lymph node metastases from breast carcinoma. reviewing the dilemma

1188

Lymph Node Micrometastases from Breast CarcinomaReviewing the Dilemma

BACKGROUND. The presence or absence of regional lymph node metastases hasKambiz Dowlatshahi, M.D.1

been one of the most important determining factors in recommending adjuvantMing Fan, M.D.1

chemotherapy for patients with breast carcinoma. However, because of the 15–Howard C. Snider, M.D.2

20% failure rate at 5 years for lymph node negative patients, other tumor-relatedFahim A. Habib, M.D.1

prognostic factors have gained greater significance in this decision-making process.

Many investigators have reported finding micrometastases that were not detected1 Department of General Surgery, Rush-Presby-by routine sectioning of the lymph nodes but were identified by multiple sectioningterian-St. Luke’s Medical Center, Chicago, Illi-and additional staining. This review attempts to evaluate the role of occult lymphnois.node micrometastases and their relevance to disease recurrence.2 Department of General Surgery, Baptist Medi-METHODS. A literature search of the entire MEDLINE data base was conducted.cal Center, Montgomery, Alabama.All relevant articles were reviewed for the criteria they used to define micrometas-

tases. The frequency of detection of micrometastases by various methodologies

and the prognostic significance of such deposits were examined.

RESULTS. Tumor deposits involving the lymph nodes were found to be arbitrarily

categorized as either micrometastases or macrometastases, with the cutoff point

ranging from 0.2–2.0 mm. The detection rate of such deposits by conventional

techniques was inadequate. Serial sectioning and immunohistochemistry appeared

to increase the detection rate by 9–33%. A definite survival disadvantage was noted

for patients with such occult metastases.

CONCLUSIONS. Current routine histologic examination of regional lymph nodes

underestimates breast carcinoma metastases. Serial sectioning and immunohisto-

chemistry increase the yield but are too labor-intensive and expensive for routine

use. However, the introduction of the sentinel lymph node biopsy in lieu of axillary

lymph node dissection in cases of breast carcinoma holds promise for making

these methods practical and cost-effective. Cancer 1997;80:1188–97.

q 1997 American Cancer Society.

KEYWORDS: breast carcinoma, lymph nodes, micrometastases, occult metastases.

Breast carcinoma remains an important health care problem. It isthe most common cancer in women (31%) and carries the second

highest mortality rate, exceeded only by that of lung carcinoma.1 Tra-ditional view holds that malignant cells disseminating from the pri-mary tumor are first harbored in regional lymph nodes. They mayremain quiescent there for a variable time but ultimately reach thesystemic circulation. A more recent hypothesis is that most breastcarcinomas are systemic from the outset, but the axillary lymph node

Address for reprints: Kambiz Dowlatshahi, M.D., status still has major prognostic implications.2 Therefore, it is under-Department of Surgery, Rush-Presbyterian-St. standable that in evaluation of the clinical stage of breast carcinomaLuke’s Medical Center, 1653 West Congress

and, consequently, therapy and outcome, emphasis continues to beParkway, Chicago, IL 60612.placed on axillary lymph node status. Clinical examination of theaxillary lymph nodes alone is inadequate, yielding many false-nega-Received January 27, 1997; revision received

May 14, 1997; accepted May 14, 1997. tive and even more false-positive findings. Thus, axillary lymph node

q 1997 American Cancer Society

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Lymph Node Micrometastases from Breast Carcinoma/Dowlatshahi et al. 1189

dissection and subsequent histologic examination cur- lary lymph node micrometastases (õ2 mm) and mac-rometastases (ú2 mm) and evaluated their signifi-rently are the accepted ‘‘yardsticks.’’ In approximately

16% of patients in whom tumors are classified as cance. At 8 years of follow-up, survival rates were sig-nificantly better among patients with micrometastaseslymph node negative by standard histologic examina-

tion, tumors recur within 5 years of initial treatment.3,4 than those with macrometastases and essentially thesame as those without lymph node involvement. Atti-Prospective randomized clinical trials have shown the

beneficial effects of adjuvant therapy in these high risk yeh et al.16 reevaluated the group of Huvos et al. after14 years of follow-up, still finding no adverse effect ofpatients.5–10 However, such therapy does carry atten-

dant morbidity and mortality.11 Therefore, it would be micrometastases on survival. Because the 10- and 14-year survival rates were the same, they believed thatof immense clinical value if this high risk group could

be accurately identified. a 10-year follow-up was adequate for long term evalu-ation.Technologic advances in diagnosis now allow the

detection of smaller, frequently lymph node negative In 1978 Fisher et al.17 serially sectioned negativelymph nodes at 5-mm intervals, staining every fourthbreast carcinomas. This earlier diagnosis augments the

need to accurately identify the high risk subgroup so section with H & E. The rationale for this sectioninginterval was that because tumor cells were ú 20 mmthat they alone can receive adjuvant therapy and its

injurious effects can be avoided in low risk patients. in size, sections every 20 mm should reveal all meta-static foci. Conversion to positive lymph nodes wasThe discrepancy between lymph node status on

conventional histologic examination and patient sur- observed in 19 of 78 patients (24%), with tumor depos-its occurring in 2 distinct patterns. In 10 of 19 patientsvival has been attributed to several factors.12 The carci-

noma could be systemic at the time of diagnosis with- (53%), free tumor emboli were observed in the periph-eral sinus or subcapsular lymphatic spaces. Parenchy-out involvement of regional lymph nodes, or the in-

volved lymph nodes (e.g., internal mammary, Level 3) mal involvement was present in 9 of the 19 patients(47%). The dimensions of the metastases ranged frommight not be examined. The involved lymph nodes

might be removed and examined but metastases not 0.2–1.3 mm, averaging 0.35 mm. At a mean follow-upof 5 years, there was no statistically significant survivaldetected because of inadequacies in diagnostic tech-

niques. difference between patients with and those withoutoccult micrometastases. In another study, Fisher etThis review was undertaken to examine the vari-

ous methods of detecting occult metastases in the re- al.18 further subdivided micrometastases into thoseõ1.3 mm and thoseú 1.3 mm butõ2 mm. They basedgional lymph nodes, the distinction between micro-

and macrometastases, and their prognostic signifi- this division on their previous report that 1.3 mm rep-resented the largest metastasis detected by serial sec-cance. The ability of these occult metastases to define

the high risk group requiring adjuvant therapy was tioning that was not found on routine histologic exam-ination. Dividing metastases into those ú 2 mm orõ2examined, perhaps bridging the gap between negative

lymph node status and outcome. mm yielded similar disease free survival (DFS) andoverall survival (OS) rates. The survival of patients withlymph node metastasesõ 1.3 mm was similar to thoseReview

Shortcomings in the routine histologic evaluation of patients without metastases but significantly betterthan those patients in whom the metastases wereú1.3dissected axillary lymph nodes were first demon-

strated by Saphir and Amromin in 1948.13 Employing mm (P Å 0.01).Black et al.19 defined micrometastases as tumorthe technique of serial sectioning and hematoxylin and

eosin (H & E) staining of alternate sections, they de- occupying õ20% of the sectioned area. Even by thisdefinition, no significant prognostic difference couldtected additional metastatic disease in 10 of 30 pa-

tients (33%) with primary invasive carcinoma and neg- be demonstrated between patients with and withoutmicrometastases, but outcome was poorer amongative axillary lymph nodes on routine examination.

They concluded that the routine examination of axil- those with macrometastases (P õ 0.05). Lymph nodehistologic features were used to stratify risk. Only pa-lary lymph nodes was inadequate to detect ‘‘obscure

metastases.’’ In 1961 Pickren14 confirmed the in- tients with operable disease by the 1974 TNM criteriawere included. Lymphocyte predominance, an un-creased detection of metastatic disease by serial sec-

tioning negative lymph nodes at 12-mm intervals, stimulated state, and the presence of sinus histio-cytosis were associated with a low recurrence ratefinding occult metastases in 21 of 97 cases (22%). Fol-

low-up at 5 years showed no recognizable difference (9%). Lymphocyte depletion, germinal center predom-inance, and the presence of micrometastases were as-in prognosis between the 2 groups. In 1971 Huvos et

al.15 introduced an arbitrary distinction between axil- sociated with an intermediate recurrence rate (23%),

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1190 CANCER October 1, 1997 / Volume 80 / Number 7

whereas the presence of macrometastases was associ- cells either located in the sinuses or diffusely distrib-uted in the lymphoid tissue, rendering the techniqueated with a high recurrence rate (58%).

Rosen et al.20 reviewed the original histology slides more useful in infiltrating lobular carcinoma (ILC), inwhich the neoplastic cells are smaller and may mimicof 147 patients, using the 2 mm criterion to differenti-

ate micro- and macrometastases. They also divided sinus histiocytosis. The small number of patients andlimited follow-up precluded evaluation of prognosticthe study population into those with tumors õ 2 cm

(T1N1M0) and tumors ú 2 cm (T2N1M0). In the first significance. Trojani et al.,25 using 5 monoclonal anti-bodies directed against epithelial antigens, found me-3 years, only macrometastases in the T1N1M0 group

were associated with a higher recurrence rate, and tastases in 21 of 150 cases (14%). They also noted ahigher conversion rate for ILC. A mean follow-up ofeven that difference was not statistically significant.

No difference could be observed between patients 10 years revealed a significant prognostic influence ofmicrometastases on both recurrence and survival (Pwith and without micrometastases in the initial 6 years

of study. A statistically significant difference evolved Å 0.0025 and 0.02, respectively) for IDC. The samplesize for ILC was too small to detect a similar signifi-at 10 years of follow-up. The prognosis for women

with a single micrometastasis and those with a single cance. Bryne et al.26 evaluated IH by restaining theoriginal slides with a monoclonal antibody to EMA,macrometastasis was nearly identical, but both groups

had poorer survival than did lymph node negative pa- finding metastases in 4 of 40 cases (10%). Three of thefour metastatic deposits were single cells. The in-tients (P Å 0.01). No statistically significant difference

could be demonstrated for the T2N1M0 group. Rosen creased yield was not believed to be of practical clini-cal value because of the additional time and expenseet al.21 further evaluated the association between intra-

mammary lymphatic emboli and the presence of oc- involved.Using 2-mm serial sections and H & E stains,cult metastases with regard to treatment failures. The

detection rate was 32% (9 of 28 cases) and all metasta- Friedman et al.27 found previously undetected tumoremboli in the sinus margins of lymph nodes in 43 ofses were õ2 mm in greatest dimension. No significant

effect on DFS or OS could be demonstrated. 456 cases (9.4%). They noted that these ‘‘clandestinemetastases’’ increased the risk of distant recurrenceWilkinson et al.12 retrospectively studied the in-

creased detection rate with serial sectioning. A 17% (P Å 0.05; relative risk, 1.7) by the same proportion asparenchymal metastases and were important prog-conversion rate was found (89 of 525 cases). Of these

89, 20% were identified on review of the original sec- nostic indicators. Berry et al.,28 using a panel of mono-clonal antibodies (HMFG1, HMFG2, E29, and CAM 5.2)tions. In 71 of the 89 (80%), the metastatic deposit

could be detected only on resectioning. These data found metastases not detected by H & E staining in17.3% of patients (13.1% for IDC and 37.5% for ILC).confirmed the findings of Huvos et al.15 and Attiyeh et

al.16 that no significant DFS or OS disadvantage was The limited number of patients and short follow-upprecluded detailed statistical analysis. Sedmak et al.,29observed in women with micrometastases compared

with those without similar foci. They did find a sig- using AE1/AE3 and anticytokeratin antibody, showedan 11% increase in the detection of metastases. Nonificantly poorer outcome independent of lymph node

status in patients with tumors õ 2 cm and in tumors evaluation of prognosis was made.Apostolikas et al.30 obtained an increased detec-with vascular or lymphatic invasion. The significance

was greater when no occult metastases were present. tion rate with serial sectioning (7 of 50 patients [14%])and noted that all occult metastases were õ1 mm inUsing immunohistochemical staining (IH) with 3

monoclonal antibodies (E29, HMFG2, and KL1), Wells size. Raymond and Leong31 pointed out that the 2 mmlimit for the differentiation of micrometastases waset al.22 detected metastases in 7 of 45 cases (15.5%)

previously believed to be lymph node negative. The purely arbitrary. The greatest dimensions of metasta-ses that they detected using CAM 5.2 and AE1/AE3increase in the detection rate was greater for lobular

carcinoma than for infiltrating ductal carcinoma (IDC) ranged from 0.2–0.6 mm. They found metastases in 7of 30 patients (23%), noting an average of 50 carci-(33% vs. 9%); most cases involved single or small clus-

ters of tumor cells. In contrast, Sloane et al.,23 using a noma cells per metastatic deposit (range, 5–200 cells).The first major prospective study was that of thesingle monoclonal antibody to epithelial membrane

antigen (EMA), found no increase in the detection rate. International (Ludwig) Breast Cancer Study Group.32

Serial sectioning and H & E staining in 921 patientsBussolati et al.24 confirmed the value of IH, detectingmetastases in 12 of 59 cases (20%) using the mono- with Stage I breast carcinoma revealed metastatic dis-

ease in 83 patients (9%). At 5 years the DFS rates forclonal antibodies EMA, HMFG2, and antikeratin com-pared with 5 of 50 cases (10%) using H & E alone. patients with micrometastases compared with those

with negative lymph nodes were 58% versus 74% (P ÅMetastases detected were mainly isolated noncohesive

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0.003) and OS rates were 79% versus 88% (P Å 0.002). would become larger. The other might not be in anearly stage but was small for other reasons such as anThe addition of perioperative chemotherapy increased

DFS in the former group. The authors concluded that effective host response or insufficient angiogenesis.They postulated that the former would be associated‘‘the pathological examination of a single H & E

stained node section is probably no longer clinically with an effectively metastasizing tumor and wouldportend an unfavorable prognosis. The latter might betenable.’’ Neville et al.33 reported that at 6 years of

follow-up, DFS (53% vs. 71%; P Å 0.0008) and OS (70% more common in larger tumors but might not neces-sarily be associated with a poor prognosis.vs. 86%; P Å 0.0009) achieved even greater statistical

significance. It was their opinion that the only re- Hainsworth et al.40 evaluated 343 cases with IH(BC2/BC3 and 3E1.2), finding occult metastases in 41maining issue was that of achieving the increased de-

tection of micrometastases without the tedium of se- cases (12%), 10 of which also were found to be positiveon blind review of H & E stains. Thirty-one of therial sectioning.

Springall et al.34 confirmed an increased detection occult metastases wereõ2 mm in greatest dimension.At a median follow-up of 79 months, the presence ofrate with IH (8 of 40 [20%]) and reported that a larger

study with longer follow-up was underway. Galea et occult metastases predicted a higher recurrence rate(32% vs. 17%; P Å 0.05) but no difference in survival.al.,35 using IH staining, demonstrated a definite but

smaller increase in the detection rate. In a study of 98 When two or more lymph nodes were positive, therealso was a decreased rate of survival (P Å 0.01).patients, 3-mm sections were cut from the previously

sampled surface and stained with H & E and mono- Elson et al.41 recut the original ‘‘negative’’ lymphnodes in 97 patients and stained the 5-mm sectionsclonal antibodies to CAM 5.2 and NCRC-11. Occult

metastases were detected in 9 of 98 sections (9%); all with AE1/AE3 and DF3. Metastases were found in 20of 97 patients (20.6%), 9 of whom (9.3%) had tumor9 were CAM 5.2 positive but 1 was missed by NCRC-

11. A 14-year follow-up revealed no survival disadvan- cells that were overlooked on the original H & E sec-tions. Nasser et al.42 took 5 sections from ‘‘negative’’tage for patients with occult metastases. Chen et al.36

(1991) stained 4-mm sections in ‘‘negative’’ lymph lymph nodes 150 mm apart and evaluated them withH & E and keratin immunostaining. Fifty of 159 pa-nodes, using polyclonal and monoclonal antibodies to

cytokeratin, a monoclonal antibody to milk fat globule tients (31%) had metastases, 28 of which (56%) weredetected by both H & E and IH and an additional 22membrane antigen, and polyclonal antibodies to car-

cinoembryonic antigen (CEA). They found previously (44%) only by IH. In 19 patients (38%), metastaseswere ú0.2 mm and in 31 (62%) they were °0.2 mm.unsuspected tumor cells or microfoci in 23 of 80 pa-

tients (29%). Follow-up in 61 patients revealed distant Patients with metastasesú 0.2 mm had a worse recur-rence rate (P Å 0.02), worse DFS (P Å 0.04), and worsemetastases in 18% of lymph node positive and 2% of

lymph node negative patients (P õ 0.05). There was OS (P Å 0.07) than did those with metastases õ 0.2mm. Recurrence and survival in the latter group wereno difference in local recurrence.

Bryne et al.,37 using monoclonal antibodies CA 15- comparable to those of lymph node negative patients.In a recent study of serial sectioning and IH stain-3 and MCA, demonstrated an increased detection rate

and showed that patients with micrometastases had a ing, McGuckin et al.43 took 4 sections at 100-mm inter-vals from 208 patients. Occult metastases were de-poorer outcome after a mean follow-up of 3.6 years

(P õ 0.001). Using serial sectioning and a cutoff point tected in 53 (25%), 28 of which (53%) were located inthe capsular or subcapsular region, 13 (25%) in theof 0.5 mm to differentiate micro- from macrometasta-

ses, de Mascarel et al.38 found micrometastases in 7% parenchyma, and 12 (23%) in both regions. Approxi-mately 67% of the metastases were õ0.5 mm in great-of patients and macrometastases in 13%. There was

no significant difference in prognosis between those est dimension. At a 5-year follow-up, DFS (P Å 0.007)and OS (P Å 0.021) were poorer in patients with occultgroups, but there was a significant difference in recur-

rence (P Å 0.005) and survival (P Å 0.0369) between metastases. Involvement of more than one lymphnode, the size of metastases, and histologic and nu-lymph node negative patients and those with even a

single metastasis. clear grade were significant prognostic indicators.Molland et al.44 demonstrated that the c-erb B-2Clayton and Hopkins39 found a statistically sig-

nificant prognostic difference (P Å 0.05) between pa- oncogene may be another useful way of detecting thepresence of metastatic lymph node disease. In a studytients with micrometastases and those with no metas-

tases only in a subset with primary tumors õ 1.8 cm. of 88 lymph node negative patients with primary oper-able breast carcinoma, 28 of 88 samples (32%) stainedThe authors hypothesized that there might be two

types of micrometastases. One type was small simply positive for the c-erb B-2 oncogene. Follow-up re-vealed a statistically significant DFS (P õ 0.001) andbecause it was still in an early stage and eventually

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OS (P Å 0.003) difference that was evident at 2 years women with breast carcinoma, regardless of lymphnode status, may derive some benefit from systemicand persisted throughout the 5-year follow-up period.

In recent years, several groups have used reverse- therapy.5–10 Early results from the National SurgicalAdjuvant Breast and Bowel Project (NSABP B-13 andtranscriptase polymerase chain reaction (RT-PCR) to

further improve the detection of lymph node metasta- B14) were considered significant enough for the Na-tional Cancer Institute to adopt a novel method ofses beyond that obtained with serial sectioning and

IH. Using the marker cytokeratin 19, which is found disseminating information even before its publicationin peer-reviewed journals. They issued their first everin breast tissue but not in normal lymph nodes,

Schoenfeld et al.45 examined 57 lymph nodes, 18 of Clinical Alert9 concluding that ‘‘adjuvant hormonal orcytotoxic chemotherapy can have a meaningful impactwhich (32%) were known to contain metastatic disease

and 39 of which (68%) were histologically negative. All on the natural history of node-negative breast cancerpatients.’’ Fisher et al.7 reported the 8-year follow-up18 positive lymph nodes were positive with PCR as

well. In addition, 4 of the histologically negative lymph of NSABP B-13, one of the original studies that led tothe Clinical Alert. They randomized 760 lymph nodenodes (10%) were positive with PCR and ethidium

staining, and an additional 10 of 35 lymph nodes negative, estrogen receptor negative patients to re-ceive either chemotherapy or placebo. DFS was sig-(28.6%) were positive after Southern blot hybridiza-

tion. A two-stage amplification was too sensitive, de- nificantly superior in the treated group compared withthe placebo group (74% vs. 59%; Põ 0.001). This bene-tecting keratin 19 in patients with normal lymph

nodes. Forty cycles of RT-PCR and Southern blot hy- fit was observed both in patients age ° 49 years (69%vs. 56%; P Å 0.006) and those age ¢ 50 years (89% vs.bridization was the optimum method of distinguishing

metastatic lymph nodes from normal lymph nodes. 80%; P Å 0.03). Similar advantages can be gained bythe use of tamoxifen in lymph node negative, estrogenMori et al.,46 studying a variety of cancers, evaluated

the ability of RT-PCR to detect lymph node metastases receptor positive tumors as shown by the NSABP B-14 study. The early trialists’ large meta-analysis alsoby the expression of CEA mRNA. All 30 histologically

positive lymph nodes also were positive with RT-PCR. revealed systemic therapy to be of benefit in both pre-menopausal and postmenopausal lymph node nega-RT-PCR detected evidence of tumor in 47 of 87 histo-

logically negative lymph nodes, increasing the positive tive patients.5,6 On the basis of these data, many oncol-ogists adopted a policy of treating all patients systemi-rate from 26% using histology to 66% using RT-PCR.

Noguchi et al.47 studied 10 histologically positive and cally, regardless of lymph node status, but this courseoften results in overtreatment of the majority of lymph53 histologically negative lymph nodes, using RT-PCR

to detect MUC1 mRNA and keratin 19 mRNA. Both node negative patients who would do well with locore-gional therapy alone. These women are thus need-mRNAs were detected in all ten histologically positive

lymph nodes. Keratin 19 was ten times as sensitive as lessly subjected to the risk, side effects, and expenseof adjuvant therapy.MUC1 on dilution studies. Keratin 19 also detected

evidence of tumor in 5 of 53 histologically negative The traditional method of evaluating axillarylymph nodes for metastases has been shown to belymph nodes (9%) in comparison with 3 (6%) with

MUC1. In a phase of the study in which portions of notoriously unreliable.12–43,45–48 The current challengeis to define a cost-effective method of determiningall of the axillary lymph nodes were pooled before RT-

PCR, those in one patient were histologically positive which lymph nodes are truly negative and which har-bor occult metastases. How this information thenbut negative by RT-PCR. The authors speculated that

this false-negative finding could have resulted from should be used in making therapeutic decisions needsclarification.dilution by the normal lymph nodes in the axilla or

possibly because the portion of the lymph node thatwas pooled contained no tumor. Definition of Micrometastases

Lymph node metastatic involvement has been arbi-trarily subdivided into micro- and macrometastases,DISCUSSION

The advent of screening mammography has led to the usually according to the size of the tumor deposits,with the cutoff point ranging from 0.2–2.0 mm.15,42increased detection of nonpalpable breast carcino-

mas, an increasing proportion of which are small and One group of authors19 defined micrometastases as õ20% involvement of the lymph node sectional area;lymph node negative. This trend poses a dilemma for

the clinician, who must decide which patients to treat this parameter is even more arbitrary because of thegreat variability in lymph node size and in enlarge-with adjuvant systemic therapy. In ú15% of lymph

node negative patients, tumors recur within 5 years ment due to factors other than metastases. The au-thors of the current study see no useful purpose inof initial therapy. Several studies have shown that all

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continuing the arbitrary, inconsistent division of of cells may be mistaken for histiocytes on routinestaining.lymph node involvement into micro- and macrome-

tastases. The presence of any tumor in a lymph node, The use of extensive serial sectioning and IH onall axillary lymph nodes is too expensive and labor-regardless of size, must be considered in light of what

it implies about tumor biology. A single malignant cell intensive to be practical. However, it has been shownthat the vast majority of lymph node metastases woulddetected in a subcapsular sinus by IH has demon-

strated the capacity to break through anatomic barri- be detected by taking 2 sections 0.3 mm apart andstaining them with a single monoclonal antibodyers (basement membrane, interstitium, etc.) but has

not demonstrated its ability to survive in the hostile (BC2).43 It appears reasonable to implement such apolicy for those patients in whom the detection ofenvironment. Surrounded by lymphocytes and im-

mune substrates, one of two fates awaits the intruder: occult metastases would alter their adjuvant therapy.In many centers these patients would be those withit can be destroyed by the body’s immune system, or it

can establish a new home, multiply, grow, and perhaps tumorsõ1 cm in size, who would not be treated unlesslymph node metastases were demonstrated.even spread from there to yet another location. Circu-

lating tumor cells may be detected by RT-PCR as well, The use of RT-PCR has been shown to detect oc-cult lymph node metastases, but the usefulness of thisand their significance currently is unknown. In con-

trast, a group of cells in the parenchyma, regardless technique awaits clarification. It even may be too sen-sitive, detecting single circulating cells that have notof how small, likely indicates the biology of the tumor

allows survival and growth in sites other than the pri- established the ability to survive in the lymph nodeand may have no clinical significance.mary location. Whether some small clusters remain

relatively dormant as postulated by Clayton and Hop-kins39 whereas others grow aggressively, remains to be Occult Metastases and Their Relation to Prognosis

The impact of occult metastases on prognosis hasclarified.been an issue of great debate. Initial studies14–17 didnot reveal any survival disadvantage in patients found

Occult Metastasis Detection Rate to have ‘‘micrometastases.’’ Consequently, these smallNearly half a century ago, it was clearly demonstrated foci of tumor were not believed to be of clinical sig-that the procedure of obtaining a few sections through nificance, and it was generally believed that a searchthe middle of a lymph node and staining them with H & for them probably was unwarranted. More recentE was woefully inadequate for detecting metastases.13

studies have shown that opinion to be no longer tena-Nevertheless, that technique remains the standard in ble. Rosen et al.20 found that patients with T1 primariesmost pathology laboratories. The increased yield of serial had poorer DFS and OS at 10 years even if their lymphsectioning with H & E staining has been reported vari- node metastases were õ2 mm in greatest dimension.ously as ranging from 7–33% (Table 1).12–15,17–21,27,30,32

No such survival disadvantage was found for T2 pa-Analysis of these reports reveals great variability in terms tients, supporting the later contention of Clayton andof the sectioning interval. The Ludwig group32 sectioned Hopkins39 that small lymph node metastases might beeach block at 6 levels and prepared 6 3-mm sections at qualitatively different, depending on the size of theeach level. They found one of the lowest conversion rate primary. In a large study, Wilkinson et al.12 failed to(9%) of all studies to date and attributed their low yield show a survival disadvantage for occult metastases,to inadequate sectioning and the lack of IH staining. Use but every study since then of at least 100 patients hasof a 48-mm sectioning interval21 increased the yield to shown decreased DFS or OS for at least a subset of32%. Therefore, it is obvious that serial sectioning with patients.25,27,32,38–40,42,43 This survival disadvantage hasH & E is superior to routine histopathology, but the been demonstrated for small tumor deposits down tosectioning interval has a significant impact on the detec- a size of only 0.2 mm.42 It is likely that with largertion rate. series and longer follow-up, even smaller metastases

A number of studies have confirmed the increased will be found to be significant.ability of IH to detect metastatic cells in lymph node Rosen et al.49 showed that with 6-year follow-up,tissue. A variety of monoclonal antibodies have been survival rates for patients with ‘‘micrometastases’’used, with detection rates ranging from 10–23% (Table were similar to those for lymph node negative patients,1).22,23,25,26,34,37,41,48 The addition of IH has been shown but at 10 years, survival rates were distinctly poorerconsistently to increase the yield from 14% to 17% for patients with ‘‘micrometastases’’ and similar toin comparison with H & E staining alone.24,28,29,42 The those of patients with ‘‘macrometastases.’’ Attiyeh etincreased yield has been greater for infiltrating lobular al.,16 although demonstrating no difference in out-

come, did show that the rates at 10 and 14 years ofcarcinoma, in which the single small cells or clusters

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TABLE 1Studies of Micrometastases, their Detection Rate, and Prognostic Significance

% of lymph Follow-upNo. of Staining nodes period

Author Year cases Sections method positive (yrs) DFS OS

Saphir and Amromin13 1948 30 332 sections per block H & E 33 3 — —Pickren14 1961 51 12-mm sections H & E 22 5 NS NSHuvos et al.15 1971 208 — H & E — 8 NS NSAttiyeh et al.16 1977 105 — H & E — 14 NS NSFisher et al.17 1978 78 Sec at 5 mm, stain every H & E 24 5 NS NS

fourthSloane et al.23 1980 39 Original section IH No increase — — —Black et al.19 1980 172 — H & E 7.50 3 NS NSRosen et al.20 1981 147 Original section H & E — 10 — P Å 0.01b

Rosen et al.21 1982 28 48-mm sections H & E 32 10 NS NSWilkinson et al.12 1982 525 24-mm and 48-mm H & E 17 15 NS NS

sectionsWells et al.22 1984 45 Serial sections H & E and IH 20 — — —Bussolati et al.24 1986 50 5 serial sections H & E and IH 24 3.5 — —Trojani et al.25 1987 150 Original sections IH 14 10 P Å 0.0025 P Å 0.02Byrne et al.26 1987 40 Original sections IH 10 5 NS NSFriedman et al.27 1988 456 1-2-mm serial sections H & E 9.40 10 — P Å 0.05Berry et al.28 1988 50 4-mm sections IH 17.40 2 — —Sedmak et al.29 1989 5 4-mm sections H & E and IH 30 — — —Apostolikas et al.30 1988 50 6 sec of 5 mm each H & E 14 — — —Raymond and Leong31 1989 30 Single section IH 23 — — —Ludwig Breast Cancer 1990 921 6 levels per block H & E 9 5 P Å 0.003 P Å 0.002

Study Group32

Springall et al.34 1990 40 — IH 20 — — —Galea et al.35 1991 98 4 3-mm sec from prv H & E and IH 9 14 NS NS

sufChen et al.36 1991 80 4-mm sections IH 29 3.2 P õ 0.05 —Neville et al.33 1991 921 6 levels per block H & E 9 6 P Å 0.0008 P Å 0.0009Byrne et al.37 1992 39 2 new sections IH 12.80 3.6 P õ 0.001 —de Mascarel et al.38 1992 336 1.5-mm slices IH 7 7 P Å 0.005 P Å 0.0369Clayton and Hopkins39 1993 399 — H & E — 16.7 P õ 0.05c —Hainsworth et al.40 1993 343 4-mm sections IH 12 6 P ú 0.05 NSElson et al.41 1993 97 4-mm sections IH 20.60 5.7 NS NSNasser et al.42 1993 159 5-mm sec at 150-mm H & E and IH 31 11 P Å 0.02c P Å 0.07

intervalsMcGuckin et al.43 1996 208 4 levels 100 mm apart H & E and IH 25 5 P Å 0.021 P Å 0.007

DFS: disease free survival; OS: overall survival; sec: section; prv suf: previously sampled surface; H & E: hematoxylin and eosin; IH: immunohistochemistry; NS: not significant.a For metastases ú1.3 mm in greatest dimension.b For T1N1M0 tumors only.c For the subset of primary tumors õ1.8 cm.d For metastases ú0.2 mm.

follow-up were similar. This suggests that future stud- had inadequate numbers of patients (range, 28–105patients) to detect small differences in sur-ies should have at least 10 years of follow-up.

At first glance, it is puzzling that many early stud- vival.14,16,17,21,26,35,41 Others had relatively short follow-up periods (range, 3–5.7 years), which are inadequateies failed to show survival differences in patients with

occult metastases, whereas more recent studies have to detect survival differences in patients with breastcarcinoma.14,17,19,26,42 All studies that showed survivalconsistently shown such differences. Closer scrutiny

reveals that, with the exception of the article by Wilkin- differences had larger patient populations (range, 147–921 patients),20,25,27,32,38–40,42,43 follow-up of at least 6son et al.,12 the differences can be accounted for by

patient population size, length of follow-up, the use years,20,25,27,33,39,42 or detection of occult lymph nodemetastases by IH.25,36–38,40,42,43 It is likely that largerof IH staining, or a combination of the three. Many of

the studies that have failed to show survival differences numbers of patients, longer follow-up, or the conver-

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sion of some of the occult metastases from the ‘‘nega- tion will no doubt shed some light on the accuracyof the procedure. However, serial sectioning and IHtive’’ groups by IH would have resulted in the demon-

stration of survival differences in most of the series. staining are not a part of that study so one wouldanticipate that a significant number of occult lymphThe authors are unable to account for the lack of sur-

vival difference in the series by Wilkinson et al., which node metastases will be missed. In a limited studycurrently in progress, the authors found occult metas-had a large patient population (525), long follow-uptases in 3 of 13 positive sentinel lymph nodes (23%)(15 years), and a reasonable conversion rate (17%).12

only by serial sectioning. The metastases would haveThe relatively recent application of sentinel lymphbeen missed by routine sectioning. To the authors’node biopsy to patients with breast cancer holdsknowledge, no studies (including the current study)promise for making the use of serial sectioning andhave examined both the sentinel lymph node and allIH staining practical and cost-effective for routine use.other axillary lymph nodes by serial sectioning or IH.Such a technique already has been demonstrated toUntil that is done, one cannot say that occult metasta-be reliable in detecting lymph node metastases in pa-ses are not being overlooked in nonsentinel lymphtients with melanoma.50 Presented with a single lymphnodes when the sentinel lymph node is negative.node (or a small number of lymph nodes) most likely

The heterogeneous nature of the series in this re-to harbor metastases, pathologists could devote moreview and the fact that most series did not analyze suchtime and resources to an exhaustive evaluation of thatprognostic factors as nuclear grade, DNA ploidy, S-lymph node. For sentinel lymph node biopsy either aphase fraction, hormone receptor status, and lym-radioactive (technetium Tc 99m sulfur colloid) or vi-phatic/vascular invasion (LVI) precluded the authors’sual (isosulfan blue) tracer is injected into the regionability to analyze their impact on adjuvant therapy orof the tumor, and the lymph node to which the tracersurvival. Thus, the authors were unable to concludedrains is determined intraoperatively. Theoretically,that occult lymph node metastases are an indepen-tumor cells would have coursed through the samedent predictor of survival separate from all other prog-lymphatics to the same lymph node. Using gammanostic factors. It is possible that in the future otherprobe localization, Krag et al.51 found the radiolabeledtumor parameters may render axillary lymph node sta-sentinel lymph node in 18 of 22 patients (82%). Thetus moot. Chadha et al.54 demonstrated that tumorsentinel lymph node was positive in all 7 patients withsize, nuclear grade, LVI, and age were all determinatesaxillary lymph node metastases and was the only focusfor lymphatic metastases. Tumor size and LVI wereof metastases in 3 patients (42.8%). Using isosulfanindependent predictors in multivariate logistic regres-blue, Giuliano et al.,52 found the sentinel lymph nodesion analyses. Seventeen of 25 patients (68%) within 114 of 174 patients (65.5%). The sentinel lymphboth features had lymph node metastases in contrastnode accurately predicted axillary lymph node statuswith 7 of 79 patients (9%) who had neither feature.in 109 of the 114 patients (95.6%). With experience,Bland et al.55 evaluated Ha-ras, c-myc, c-fos, and p53Giuliano et al. were able to detect the sentinel lymphas prognostic discriminates for breast carcinoma,node in 78% of patients.52 The authors’ own experi-finding an increasing likelihood of recurrence with in-ence with use of a gamma probe revealed a detectioncreasing oncogene coexpression. Expression of 1 on-rate ú 90%, with a relatively short learning curve (un-cogene predicated a 17.2% chance, 2 oncogenes apublished data). When the sentinel lymph node was56.3% chance, and 3 or 4 oncogenes a 100% chanceevaluated with serial sectioning and IH, Giuliano etof recurrence (P Å 0.001).al.53 found metastases in 68 of 162 patients (42%) in

Future studies should include a comparison be-comparison with 39 of 134 patients (29%) when thetween sentinel lymph nodes and the remainder of thefull axillary lymph node dissection was processed inaxillary lymph nodes in which all lymph nodes arethe usual manner (P õ 0.03). The metastases weresubjected to serial sectioning and IH. The number ofsmaller than 2 mm in 4 of 39 patients (10.3%) in thepatients evaluated should be large enough to substrat-full axillary lymph node dissection group, comparedify them according to a number of variables, includingwith 26 of 68 patients (38.2%) in the sentinel lymphnot only size but also oncogene expression and en-node group (P õ 0.0005).zyme activity. Only then can a determination be madeAlthough sentinel lymph node biopsy with serialas to whether the findings on sentinel lymph nodesectioning and IH may offer a highly accurate, cost-biopsy accurately predict prognosis and serve as inde-effective method of determining axillary lymph nodependent variables.status in the future, insufficient data currently exist

to support that assumption. A large multicenter trial CONCLUSIONScurrently is in progress evaluating some aspects of sen- Advances in diagnostic techniques have led to the ear-

lier detection of breast carcinomas, the vast majority oftinel lymph node biopsy. Its conclusion and publica-

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adjuvant chemotherapy for breast cancer. Lancet 1983;which are found to be lymph node negative by routine2(8349):542–4.histology. Numerous studies have demonstrated that

12. Wilkinson EJ, Hause L, Hoffman RG, Kuzma JF, Rothwell DJ,up to 33% of these patients harbor occult tumor de-Donegan WL, et al. Occult axillary lymph node metastases

posits in the lymph nodes, which can be detected only in invasive breast carcinoma: characteristics of the primarywith serial sectioning, IH, or RT-PCR. In the past de- tumor and significance of the metastases. Pathol Annu

1982;17(Pt 2):67–91.cade, large studies with adequate follow-up have dem-13. Saphir O, Amromin GD. Obscure axillary lymph node metas-onstrated consistently that these small metastases

tases in carcinoma of the breast. Cancer 1948;1:238–41.have important prognostic implications and therefore14. Pickren JW. Significance of occult metastases. A study ofcould be important in making therapeutic decisions.

breast cancer. Cancer 1961;14:1266–71.The routine evaluation of these occult metastases 15. Huvos AG, Hutter R, Berg JW. Significance of axillary macro-must be incorporated into clinical practice. It is hoped metastases and micrometastases in mammary cancer. Ann

Surg 1971;173(1):44–6.that the refinement and widespread use of sentinel16. Attiyeh FF, Jensen M, Huvos AG, Fracchia A. Axillary micro-lymph node biopsy will allow their accurate detection

metastases and macrometastases in carcinoma of the breast.without requiring undue expenditure of time and re-Surg Gynecol Obset 1977;144(6):839–42.sources.

17. Fisher ER, Swamidoss S, Lee CH, Rockette H, Redmond C,Fisher B. Detection and significance of occult axillary nodemetastases in patients with invasive breast cancer. Cancer

REFERENCES 1978;42:2025–31.1. Parker SL, Tong T, Bolden S, Wingo PA. Cancer statistics. 18. Fisher ER, Palekar A, Rockette H, Redmond C, Fisher B.

1996. CA Cancer J Clin 1996;46:5–27. Pathologic findings from the National Surgical Adjuvant2. Fisher B, Redmond C, Fisher ER. The contribution of recent Breast and Bowel Project (Protocol #4) V. Significance of

NSABP clinical trials of primary breast cancer therapy to an axillary nodal micro- and macrometastases. Cancer 1978;understanding of tumor biology—an overview of findings. 42:2032–8.Cancer 1980;46:1009–25. 19. Black RB, Roberts M, Stewart HJ, Prescott R, Cant EL, Sumer-

3. Fisher B, Bauer M, Wickerham DL, Redmond CK, Fisher ER, ling MD, et al. The search for occult metastases in breastCruz AB, et al. Relation of number of positive axillary nodes cancer: does it add to established staging methods? Aust Nto prognosis of patients with primary breast cancer; an Z J Surg 1980;50(6):574–9.NSABP update. Cancer 1983;52(9):1551–7. 20. Rosen PP, Saigo P, Weathers E, Fracchia AA, Kinne DW. Axillary

4. Rosen PP, Saigo P, Braum DW Jr., Weathers E, Depalo A. micro- and macrometastases in breast cancer: prognostic sig-Predictors of recurrence in Stage I (T1N1M0) breast carci- nificance of tumor size. Ann Surg 1981;194(5):585–91.noma. Ann Surg 1981;193:15–25. 21. Rosen PP, Saigo P, Braun DW Jr., Beattie EJ Jr., Kinne DW.

5. Early Breast Cancer Trialists’ Collaborative Group. SystemicOccult axillary lymph node metastases from breast cancers

treatment of early breast cancer by hormonal, cytotoxic orwith intramammary lymphatic tumor emboli. Am J Surg Pa-

immune therapy: 133 randomized trials involving 31,000 re-thol 1982;6(7):639–41.

currences and 24,000 deaths among 75,000 women. Lancet22. Wells CA, Heryet A, Brochier J, Gatter KC, Mason DY. The1992;339(8785):1–15.

immunohistochemical detection of axillary micrometastases6. Early Breast Cancer Trialists’ Collaborative Group. Systemic

in breast cancer. Br J Cancer 1984;50(2):193–7.treatment of early breast cancer by hormonal, cytotoxic or

23. Sloane JP, Ormerod M, Imrie SF, Coonbes RC. The use of anti-immune therapy: 133 randomized trials involving 31,000 re-sera to epithelial membrane antigen in detecting micrometas-currences and 24,000 deaths among 75,000 women. Lancettases in histological sections. Br J Cancer 1980;42(3):392–8.1992;339(8785):71–85.

24. Bussolati G, Gugliotta P, Morra I, Pietribiasi F, Berardengo7. Fisher B, Dignam J, Mamounas EP, Constantino JP, Wick-E. The immunohistochemical detection of lymph node me-erham DL, Redmond C, et al. Sequential methotrexate andtastases from infiltrating lobular carcinoma of the breast. Brfluorouracil for the treatment of node-negative breast can-J Cancer 1986;54(4):631–6.cer patients with estrogen receptor-negative tumors: eight-

25. Trojani M, de Mascarel I, Bonichon F, Coindre JM, Delsolyear results from National Surgical Adjuvant Breast andG. Micrometastases to axillary lymph nodes from carcinomaBowel Project (NSABP) B13 and first report of findings fromof the breast. Br J Cancer 1987;55(3):303–6.NSABP B-19 comparing methotrexate and fluorouracil with

26. Byrne J, Waldron R, McAvinchey D, Dervan P. The use ofconventional cyclophosphamide, methotrexate and fluoro-monoclonal antibodies for the histopathological detectionuracil. J Clin Oncol 1996;14(7):1982–92.of mammary axillary micrometastases. Eur J Surg Oncol8. Goldhirsch A, Castiglione M, Gelber RD. The International1987;13(5):409–11.Breast Cancer Study Group. A single perioperative chemo-

27. Friedman S, Bertin F, Mouriesse H, Benchabat A, Genin J,therapy course for node-negative breast cancer: five yearSarrazin D, et al. Importance of tumor cells in axillary noderesults of trial V. Monogr Natl Cancer Inst 1992;11:89–96.sinus margins (clandestine metastases) discovered by serial9. NCI. Alert on node-negative breast cancer. Breast Cancersectioning in operable breast cancer. Acta Oncol 1988;Res Treat 1988;12:3–5.27(5):483–7.10. Fisher B, Redmond C. The National Surgical Adjuvant Breast

28. Berry N, Jones D, Marshall R, Smallwood J, Taylor I. Compar-and Bowel Project. Systemic therapy in node-negative pa-tients: updated findings from NSABP clinical trials. Monogr ison of the detection of breast carcinoma metastases by rou-

tine histological diagnosis and by immunohistochemicalNatl Cancer Inst 1992;(11):105–16.11. Ludwig Breast Cancer Study Group. Toxic effects of early staining. Eur Surg Res 1988;20(4):225–32.

/ 7b71$$1343 09-10-97 10:15:57 cana W: Cancer


29. ML. Occult axillary lymph node metastases in ‘‘node-nega-Sedmak DD, Meineke T, Knechtges DS. Detection of meta-tive’’ breast carcinoma. Hum Pathol 1993;24(9):950–7.static breast carcinoma with monoclonal antibodies to cyto-

keratins. Arch Pathol Lab Med 1989;113:786–9. 43. McGuckin MA, Cummings MC, Walsh MD, Hohn BG, Ben-nett IC, Wright RG. Occult axillary node metastases in breast30. Apostolikas N, Petraki C, Agnantis AG. The reliability of his-cancer: their detection and prognostic significance. Br J Can-tologically negative axillary lymph nodes in breast cancer.cer 1996;73(1):88–95.Pathol Res Pract 1988;184:35–8.

44. Molland JG, Barraclough BH, Gebski V, Miliken J, Bilous31. Raymond WA, Leong A-Y. Immunoperoxidase staining inM. Prognostic significance of c-erbB-2 oncogene in node-the detection of lymph node metastases in Stage I breastnegative breast cancer. Aust N Z J Surg 1996;66(2):64–70.cancer. Pathology 1989;21:11–5.

45. Schoenfeld A, Luqmani Y, Smith D, O’Reilly S, Shousha S,32. International (Ludwig) Breast Cancer Study Group. Prognos-Sinnett HD, et al. Detection of breast cancer micrometas-tic importance of occult axillary lymph node micrometas-tases in axillary lymph nodes using polymerase chain reac-tases from breast cancer. Lancet 1990;335(8749):1565–8.tion. Cancer Res 1994;54(11):2986–90.33. Neville AM, Price K, Gelber RD, Goldhirsch A. Axillary node

46. Mori M, Momori K, Inoue H, Barnard GF, Tsuji K, Nanbaramicrometastases and breast cancer. Lancet 1991;337(8749):S, et al. Detection of cancer micrometastases in lymph nodes1110.by reverse transcriptase-polymerase chain reaction. Cancer34. Springall RJ, Rytina E, Millis RR. Incidence and significanceRes 1995;55(15):3417–20.of micrometastases in axillary lymph nodes detected by im-

47. Noguchi S, Aihara T, Motomura K, Inaji H, Imaoka S, Koy-munohistochemical techniques. J Pathol 1990;160:174A.ama H. Detection of breast cancer micrometastases in axil-35. Galea MH, Athanassiou E, Bell J, Dilks B, Robertson JF, Elstonlary lymph nodes by means of reverse transcriptase-poly-CW, et al. Occult regional lymph node metastases from breastmerase chain reaction. Am J Pathol 1996;148(2):649–56.carcinoma. Immunohistochemical detection with antibodies

48. Trojani M, de Mascarel I, Coindre JM, Delsol G. Micrometas-CAM 5.2 and NCRC-11. J Pathol 1991;165(3):221–7.tases to axillary lymph nodes from invasive lobular carci-36. Chen Z-L, Wen D-L, Coulson WF, Giuliano AE, Cochran AJ.noma of the breast: detection by immunohistochemistryOccult metastases in the axillary lymph nodes of patientsand prognostic significance. Br J Cancer 1987;56:838–9.with breast cancer node negative by clinical and histological

49. Rosen PP, Saigo P, Braun DW, Weathers E, Kinne DW. Prog-examination and conventional histology. Dis Markers 1991;nosis in stage II (T1N1M0) breast cancer. Ann Surg 1981;9(5):239–48.194(5):576–84.37. Byrne J, Horgan P, England SS, Callaghan J, Given HF. A

50. Morton D, Wen D-R, Wong JH, Economou JS, Cagle LA,preliminary report on the usefulness of monoclonal anti-Storm FK, et al. Technical details of intraoperative lymphaticbodies to CA 15-3 and MCA in the detection of micrometas-mapping for early stage melanoma. Arch Surg 1992;127(4):tases in axillary lymph nodes draining primary breast can-392–9.cer. Eur J Surg 1992;28:658–60.

38. 51. Krag DN, Weaver D, Alex JC, Fairbank JT. Surgical resectionde Mascarel I, Binichon F, Coindre JM, Trojani M. Prognosticsignificance of breast cancer axillary node micrometastases and radiolocalization of sentinel lymph node in breast can-

cer using a gamma probe. Surg Oncol 1993;2:335–9.assessed by two special techniques: re-evaluation withlonger follow-up. Br J Cancer 1992;66(3):523–7. 52. Giuliano AE, Kirgan D, Guenther JM. Lymphatic mapping

39. Clayton F, Hopkins CL. Pathologic correlates of prognosis and sentinel lymphadenectomy for breast cancer. Ann Surg1994;220:391–401.in lymph node positive breast carcinomas. Cancer 1993;

71(5):1780–90. 53. Giuliano AE, Dale P, Turner RR, Morton DL, Evans SW,40. Hainsworth PJ, Tjandra J, Stillwell RG, Machet D, Henderson Krasne DL. Improved axillary staging of breast cancer with

sentinel lymphadenectomy. Ann Surg 1995;222(3):394–401.MA, Rennie GC, et al. Detection and significance of occultmetastases in node-negative breast cancer. Br J Surg 1993; 54. Chadha M, Chabon AB, Friedmann P, Vikram B. Predictors80(4):459–63. of axillary lymph node metastases in patients with T1 breast

41. Elson CE, Kulfe D, Johnson WW. Immunohistochemical de- cancer: a multivariate analysis. Cancer 1994;73:350–3.tection and significance of axillary lymph node micrometas- 55. Bland KI, Konstadoulakis MM, Vezeridis MP, Wanebo HJ.tases in breast carcinoma. Anal Quant Cytol Histol Oncogene protein coexpression: value of Ha-ras, c-myc, c-1993;15(3):171–8. fos, and p53 as prognostic discriminates for breast carci-

42. Nasser IA, Lee A, Bosari S, Saganich R, Heatley G, Silverman noma. Ann Surg 1996;221(6):706–20.

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lymph node metastases from breast carcinoma. reviewing the dilemma

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