Dr KP TsuiDepartment of Surgery

Tseung Kwan O Hospital

Malignant Rectal PolypPolyps with cancer cells invading the

muscularis mucosaInvasion limited to submucosa T1 lesion

Incidence of malignant colorectal polyps as a proportion of all adenomas removed varies between 2.6 and 9.7%.

Average 4.7%

Sobin L, Wittekind C (eds). TNM classification of Malignant Tumours (6th Edition). Wiler-Liss: New York, 2002.

Size most important determinant factor determining risk of malignant transformation within a polyp

> 1 cm: 38.5%> 42 mm: 78.9%

Tytherleigh et al. BJS 2008;95:409-423

Villous adenomas have highest risk of malignancy at 29.8%

Tubular adenomas have lowest at 3.9%

Tytherleigh et al. BJS 2008;95:409-423

Haggitt Classification

Kikuchi Classification of Adenocarcinoma in Sessile Polyps

Treatment Staging Histological Assessment

Clinical Scenario 1Colonoscopy: 2 cm rectal polyp

(5 cm from anal verge)Biopsy: adenocarcinoma

Endorectal ultrasound

Best method to differentiate between T1 and T2 lesion

T stage N stage Accuracy: 90 % Accuracy: 80%

Sensitivity : 85% Sensitivity: 70%Specificity: 95% Specificity: 80%

Bretagnol et al. Dis Colon Rectum 2007;50:523-533

Can assess residual tumor after polypectomy

Follow up after local excision

Hernandez De Anda et al. Dis Colon Rectum 2004; 47: 818–824

LimitationsOperator dependent

Upper rectal lesions

Tumor stenosis

Peritumoral fibrosis and inflammatory tissue

Effect of radiotherapy or hemorrhage after

biopsy

Pelvic MRIOverall T stage accuracy 59-95%T1,2 lesion (vs ERUS)

- Similar sensitivities- Lower specificity (69%)

N stage - Comparable to EUS

Can evaluate entire pelvis

Bretagnol et al. Dis Colon Rectum 2007;50:523-533Tytherleigh et al. BJS 2008;95:409-423

CT abdomen + pelvis Distant metastasesLow accuracy for T staging, 52 – 94% and N stage,

54-70%

Alexandre Jin Bok Audi Chang et al. Journal of Surgical Education; Vol 65: Number 1Bretagnol et al. Dis Colon Rectum 2007;50:523-533

PETLimited role for local and regional stagingSensitivities for lymph node metastases 22-

29%

Abdel-Nabi H, Doerr RJ, Lamonica DM, et al. Radiology. 1998;206:755-760

Surgical OptionsLocal excision vs Radical Surgery

Park’s per anal excision Abominoperineal

resection

TEM Total Mesorectal

Excision

Anterior

resection

Local ExcisionOpportunity of cure with less detriment

Sphincter preservation

Less morbidity and mortality

Less sexual or urinary dysfunction

Park’s per anal excision- Aid of anal retractors

- 6-10 cm of anal margin

- Full thickness excision

- At least 1 cm margin

- Defect usually closed with absorbable sutures

Transanal endoscopic microsurgeryRectoscope

Usually below peritoneal reflection

Full thickness excision

Excision margin of 1 cm Difficult for lesions within 6 cm

Long-handled transanal endoscopic microsurgery instrument

ComplicationsOverall rate 6-31%

Postoperative hemorrhage 1-13%

Perforation 0-9%

Suture line dehiscence

Perirectal abscess

Rectal stenoses

Hiroko Kunitake, et al. Perm J 2012 Spring;16(2):45-50

Local Excision

Vs

Radical Surgery

Generally accepted that local excision, by either

endoscopic polypectomy or transanal surgery is

adequate treatment for low risk ERC

Tytherleigh et al. BJS 2008;95:409-423

Histopathological FeaturesLow risk early rectal cancer High risk early rectal cancer

Well or moderately differentiated Poorly differentiated

No vascular or lymphatic invasion

Vascular or lymphatic invasion

Hagitt 1-3Kikuchi Sm 1 and ?Sm2

Kikuchi Sm3 and ?Sm2Positive resection margin

Poorly differentiated carcinoma: 50% risk

of lymph node metastasis

Coverlizza S, Risio M, Ferrari A, Fenoglio-Preiser CM, Rossini FP. Cancer 1989;64:1937-47

Lymphovascular invasion, sm3 invasion,

undifferentiated carcinomas have

significant risks of LN metastases.

Nascimbeni et al. Dis Colon Rectum 2002;45:200-206

Des.

Depth of invasion was found to be best estimate of the probability of regional LN metastasis

Bretagnol et al. Dis Colon Rectum 2007;50:523-533

Rate of lymph node metastasis

Sm1 1-3%

Sm2 8%

Sm3 23%

Nascimbeni et al. Dis Colon Rectum 2002;45:200-206

Optimal choice of surgeryThe role of local excision as a curative

procedure has been questioned due to inferior outcome in some long term follow up series.

Alexandre Jin Bok Audi, MD, et al. Journal of Surgical Education; Vol 65: Number 1 (2008)

Alexandre Jin Bok Audi, MD, et al. Journal of Surgical Education; Vol 65: Number 1 (2008)

Most literature data are based on case reports or small series with no standard criteria for patient selection

Adjuvant chemoradiotherapyMay be beneficial Recommended for high risk T1 lesions,

assuming further surgery is not an option

Tytherleigh et al. BJS 2008;95:409-423

Bretagnol et al. Dis Colon Rectum 2007; 50:523-533

LimitationsMost retrospective studiesLack of controlled dataNo defined protocol for chemotherapy

Salvage surgery Between 56 and 100% of recurrence suitable

for salvage surgeryMay not offer same outcomes as initial

treatmentShould not be delayed in case of recurrence

Tytherleigh et al. BJS 2008;95:409-423

Clinical Scenario 2Colonoscopic polypectomy of rectal polypPathology: adenocarcinoma

Radical Surgery Follow up

ERUS MRI CT

LN+

High Risks FeaturesSm3 (Sm2)Gradelymphovascular

No High Risks FeaturesHaggitt level 1,2,3 Kikuchi Sm1

Margin involvement

Yes

Local Excision

Histological assessment not

adequate

No

High Risks Features

NoYes

LN-

Pathology

Follow up Digital rectal exam + Endoscopy + CEA

First 3 years: every 3 monthsNext 2 years: every 6 monthsThen annually

Endorectal ultrasound should be performed at every outpatient session

Mellgren et al. Dis Colon Rectum 2000; 43: 1064–1071NCCN guideline

SummaryLocal excision

Recommended for low risk T1 Sm1 lesionRadical surgery

For high risk T1 lesion Adjuvant therapy if further surgery is not an option

Recurrence Diagnose early for salvage surgery

Follow up Endoscopic surveillance of rectum and scar