Colorectal Cancer Study Group-12trial,3 and the Adjuvant ZoledronicAcid to Reduce Recurrence trial,4 allsuggested that the inhibition of oste-oclast activity with zoledronic acidcan result in reductions in distantrecurrence in postmenopausal womenwith early-stage breast cancer (eithernaturally through aging or via lutein-izing hormone-releasing hormoneagonists). Meta-analyses of thesetrials are currently under way. Somedebate exists concerning the interpre-tation of the results of these trialsbecause disease-free survival was notthe primary endpoint in some of thetrials and subset analysis was used inthe interpretation of the results ofothers. Nonetheless, when at least 4well-conducted phase III trials allpoint in the same direction, a real andclinically significant biological effectis likely.

The theory of overactive boneresorption resulting in increasedrecurrence predicts that postmeno-pausal women with overactive boneresorption should have a higherrecurrence rate from early-stagebreast cancer. In the article by Liptonand colleagues, this is exactly what

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happens. In this retrospective case-control study of postmenopausalwomen enrolled in the NationalCancer Institute of Canada MA.14trial of tamoxifen with or withoutoctreotide, women with a pretreat-ment serum B-CTx of collagen greaterthan 0.710 ng/ml had a 3.5-foldhigher risk of bone metastasis and asignificantly shorter bone metastasisefree survival duration.

These data support the contentionthat suppression of bone resorptionmay change the natural history ofearly-stage breast cancer in postmen-opausal women. Rare toxic effects (eg,osteonecrosis of the jaw, renal insuf-ficiency, insufficiency fracture, and apotentially increased risk of esopha-geal cancer with oral bisphospho-nates) of anti-resorptive therapies doexist, and these therapies should beused for this indication with caution;however, the benefits of anti-resorptivetherapies seem to far outweigh therare risks. We may be on the cusp ofthe widespread adoption of suchtherapies to reduce breast cancerrecurrence in postmenopausal women.

A. Brufsky, MD, PhD

terly

References1. Brufsky AM, Harker WG, Beck JT,

et al. Final 5-year results of Z-FASTtrial: adjuvant zoledronic acidmaintains bone mass in postmeno-pausal breast cancer patients receivingletrozole. Cancer. 2012;118:1192-1201.

2. Eidtmann H, de Boer R, Bundred N,et al. Efficacy of zoledronic acid inpostmenopausal women with earlybreast cancer receiving adjuvantletrozole: 36-month results of the ZO-FAST Study. Ann Oncol. 2010;21:2188-2194.

3. Gnant M, Mlineritsch B, Stoeger H,et al; Austrian Breast and ColorectalCancer Study Group, Vienna, Austria.Adjuvant endocrine therapy pluszoledronic acid in premenopausalwomen with early-stage breastcancer: 62-month follow-up from theABCSG-12 randomised trial. LancetOncol. 2011;12:631-641.

4. Coleman RE, Marshall H, Cameron D,et al; AZURE Investigators. Breast-cancer adjuvant therapy withzoledronic acid. N Engl J Med. 2011;365:1396-1405.

Comparison of estrogen andprogesterone receptor status ofcirculating tumor cells and theprimary tumor in metastaticbreast cancer patients

Aktas B, Müller V, Tewes M, et al (Univ ofEssen, Germany; Univ Med Ctr Hamburg-Eppendorf, Germany; et al)

Gynecol Oncol 122:356-360, 2011

Objectives.dTheexpressionofpre-dictive markers including the estrogen(ER) and progesterone receptor (PR)

expression can change during the courseof the disease. Therefore, reassessmentof these markers at the time of diseaseprogression might help to optimizetreatment decisions. Metastatic tissuemay be difficult to obtain for repeatedanalysis. In this context, characteriza-tion of circulating tumor cells (CTCs)could be of relevance. It was the purposeof the present study (1) to reevaluate theER/PR expression by CTCs and (2) tocompare the hormone receptor statusexpression profile of CTCs with theprimary tumor.

Methods.dWe evaluated 193 bloodsamples from metastatic breast cancerpatients at the time of first diagnosis ofmetastatic diseaseordiseaseprogression.All samples underwent immunomag-netic enrichment using the AdnaTestBreastCancerSelect (AdnaGen AG,Germany) within 4 h after blood with-drawal followed by RNA isolation andsubsequent gene expression analysis byreverse transcription and Multiplex-PCR in separated tumor cells using theAdnaTest BreastCancerDetect. CTCswere analyzed for the three breast

cancer-associated markers: EpCAM,Muc-1, Her-2 and actin as an internalPCR control. Expression of the ER andPR was assessed in an additional RT-PCR. The analysis of PCR products wasperformed by capillary electrophoresison the Agilent Bioanalyzer 2100.

Results.dThe overall detectionrate forCTCswas 45% (87/193 patients)with the expression rates of 71% forEpCAM (62/87 patients), 73% forMUC1 (64/87 patients), 48% for HER2(42/87 patients), 19% for ER (17/87patients) and 10% for PR (9/87 patients),respectively. Comparisons with the pri-mary tumor were only performed inCTC+ patients (n¼ 87). In 48/62(77%) patients with ER+ tumors, CTCswere ER� and 46/53 (87%) patientswith PR+ tumors did not express PRon CTCs. Primary tumors and CTCsdisplayed a concordant ER and PRstatus in only 41% (p¼ 0.260) and45% (p¼ 0.274) of cases, respectively.

Conclusion.dMost of the CTCswere ER/PR-negative despite the pres-ence of an ER/PR- positive primarytumor. The predictive value of hormonereceptor status expression profile ofCTCs for palliative endocrine therapyhas to be prospectively evaluated.

Statement.dWe recently demon-strated in more than 400 primary breastcancer patients that the expression pro-file between CTCs and the primarytumorwith regard to ER/PR/HER2 posi-tivity differs. The concordance ratebetween ER, PR and HER2 status ofCTCs and the primary tumor was 29%,25% and 53%, respectively (Fehm Tet al., Breast Cancer Res Aug 10 2009,11(4) pR59). Based on these results westudied blood samples of 193 metastaticbreast cancer patients participating in theGerman DETECT study (1) to reevalu-ate the ER/PR expression by CTCs and(2) to compare the hormone receptorstatus expression profile of CTCs withthe primary. As already shown for pri-mary breast cancer, most of the CTCs

were ER/PR-negative despite the pres-ence of an ER/PR- positive primarytumor. In the metastatic setting thephenotype of CTC reflects the pheno-type of metastatic disease. Thereforepalliative treatment selected based onthe expression profile may not be effec-tive since the phenotype has changedduring disease progression. To ourknowledge, this study is one of thebiggest to compare hormonal receptorexpression on CTC and the primarytumor. We hope that our manuscript issuitable for publication in GynecologicOncology.

Reassessment of ER and PR ex-pression in breast cancer patients isrecommended at the time of tumorrecurrence, as the expression status ofpredictive markers can change duringthe course of the disease. The authorsof this article hypothesized that, inpatients with metastatic breast cancer,ER and PR expression in CTCs wouldreflect the phenotype of the metastaticdisease. If so, treatment decisions couldbe based on the assay results of a bloodsample rather than a tissue biopsy.This would be particularly useful forpatients in whom tissue from themetastatic site is difficult to obtain.

The authors observed that 48(77%) of 62 patients with ER-positiveprimary tumors had ER-negativeCTCs, and 46 (87%) of 53 patientswith PR-positive primary tumors hadPR-negative CTCs. They suggestedthat hormone receptor-negative CTCsindicate a likelihood of hormonereceptor-negative metastatic diseaseand concluded that further studiesshould be performed to prospectivelyevaluate the predictive value of thehormone receptor status of CTCs forassessing the effectiveness of pallia-tive endocrine therapy.

Although the notion that CTCsobtained at the time metastatic diseaseis discovered might share its predictive

Breast D

marker phenotype is an attractivehypothesis, it is important to note thatin a previous study in which CTCswere obtained at the time of theprimary tumor diagnosis, the sameauthors found a similarly markeddecrease in hormone receptor expres-sion in the CTCs compared with theprimary breast cancers.1 In ER-positive primary breast cancers, theyobserved ER-negative CTCs in 71% ofpatients, and in PR-positive primarybreast cancers, they observed PR-negative CTCs in 75% of patients. Thisrate of discordance is much greaterthan that observed between primaryand recurrent breast cancers.2

Others have hypothesized thatCTCs and disseminated tumor cells inbone marrow have a stem cell pheno-type.3 If this is true in at least a largeproportion of cases, it would explainthe apparent down-regulation ofhormone receptors in the CTCs ofmany patients. Regardless of whetherCTCs have a stem cell-like phenotype,however, empirical data suggest thatCTCs do not faithfully represent thepredictive marker phenotype of therecurrent tumors. We would not likelyconsider withholding endocrinetherapy from over 70% of primarybreast cancer patients with hormonereceptor-positive tumors just becausetheir CTCs were hormone receptornegative. Evidence to date suggeststhat the majority of patients withhormone receptor-positive disease areat risk for recurrence of hormonereceptor-positive disease.2

As the discordance observedbetween the primary tumor and CTCsobtained at the time the primary tumoris diagnosed is just as great as thediscordance observed when CTCs areobtained at the time of tumor recur-rence, the predictive value of thehormone receptor status of CTCs forpalliative endocrine therapy inpatients with metastatic disease may

iseases: A Year Book� Quarterly 245Vol 23 No 3 2012

be just as low as the predictive valueappears to be in primary breast cancer.

M. Z. Gilcrease, MD, PhD

References1. Fehm T, Hoffman O, Aktas B, et al.

Detection and characterization of

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circulating tumor cells in blood ofprimary breast cancer patients by RT-PCR and comparison to status of bonemarrow disseminated cells. BreastCancer Res. 2009;11:R59.

2. Liedtke C, Broglio K, Moulder S,et al. Prognostic impact ofdiscordance between triple-receptormeasurements in primary and

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recurrent breast cancer. Ann Oncol.2009;20:1953-1958.

3. Balic M, Lin H, Young L, et al. Mostearly disseminated cancer cellsdetected in bone marrow of breastcancer patients have a putative breastcancer stem cell phenotype. ClinCancer Res. 2006;12:5615-5621.

An increase in cancer stem cellpopulation after primary systemictherapy is a poor prognosticfactor in breast cancer

Lee HE, Kim JH, Kim YJ, et al (Seoul NatlUniv Hosp, Jongno-gu, Korea; Seoul NatlUniv College of Medicine, Jongno-gu,Korea; et al)

Br J Cancer 104:1730-1738, 2011

Background.dThecancer stemcell(CSC) hypothesis has important clinicalimplications for cancer therapeuticsbecause of the proposed role of CSCsin chemoresistance. The aim of thisstudy was to investigate changes in theCSC populations before and after pri-mary systemic therapy (PST) and theirprognostic role in human breast cancer.

Methods.dPaired samples (beforeand after PST) of breast cancer tissuewere obtained from clinical stage II orIII patients (n¼ 92) undergoing PSTwith the regimen of doxorubicin plusdocetaxel (AD) (n¼ 50) or doxorubicinplus cyclophosphamide (AC) (n¼ 42)and subsequent breast resection. Theproportions of putative CSCs withCD44+/CD24� or aldehyde dehydroge-nase 1 + (ALDH1 +) phenotypes weredetermined by immunohistochemistry.

Results.dA higher proportion ofCD44+/CD24� tumour cells andALDH1 positivity in pre-chemotherapytissue was correlated with higher histo-

logic grade, oestrogen receptor (ER)negativity, high Ki-67 proliferationindex and basal-like subtype of breastcancer. Aldehyde dehydrogenase 1 posi-tivity in pre-chemotherapy biopsy wasalso associated with a higher rate ofpathologic complete response followingPST. In comparisons of putative CSCpopulations before and after PST, theproportions of CD44+/CD24� andALDH1 tumour cells were significantlyincreased after PST. The cases withincreased CD44+/CD24� tumour cellpopulations after PST showed highKi-67 proliferation index in post-chemotherapy specimens and thosewith increased ALDH1 + tumour cellpopulation after PST were associatedwith ER negativity and p53 overexpres-sion. Furthermore, cases showing suchan increase had significantly shorterdisease-free survival time than thosewith no change or a reduced number ofCSCs, and the survival difference wasmost notable with regard to the changesof ALDH1 + tumour cell population inthe patients who received AC regimen.

Conclusion.dThe present studyprovides the clinical evidence that theputative CSCs in breast cancer are che-moresistant and are associated withtumour progression, emphasising theneed for targeting of CSCs in the breastcancer therapeutics (Fig 4).

The occurrence of distant meta-static disease in breast cancer patients

after complete surgical resection hasled to the common conception thatmicrometastases from the primarytumor disseminate to other parts of thebody. The ability of these cells to mani-fest years after the original diagnosisdespite aggressive adjuvant chemo-therapy has provided circumstantialevidence of a “stem cell hypothesis.”1

This hypothesis is based on the notionthat there are seed cells (so-calledCSCs)within the primary tumor that arefundamentally refractory to therapy andthat these cells, despite their smallnumbers, are the ones that metastasizeto areas outside the breast and give riseto metastatic lesions. These cells arethought to be “stem-like” because oftheir intrinsic self-renewing properties.Their resistance to treatment is thoughtto occur via a variety of mechanisms,including enhanced DNA repair, highexpression of adenosine triphosphate-binding cassette drug transporters, andactivation of the PI3K/ACTand Wntpathways.2 They also appear to takeadvantage of favorable microenviron-mental conditions, moving in and outof a quiescent state in response to stressand demonstrating plasticity by movingthrough the epithelial-mesenchymaltransition (EMT).3 While defining thiscell population histopathologically hasbeen difficult, the most common CSCmarkers include low expression ofCD24, high expression of CD44, andthe presence of ALDH1.