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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