Malignant Rectal Polyp Joint Hospital Surgical Grand Round 18 Apr 2009 Malignant Rectal Polyp Dr Kit-wai Lai Department of Surgery Tuen Mun Hospital
Malignant Rectal Polyp Polyps with cancer cells penetrating the muscularis mucosa Invasion limited to submucosa i.e. T1 lesion
Size the most important factor determining risk of malignant transformation within a polyp Tytherleigh et al. BJS 2008;95:409-423 >1cm 38.5% >42mm 78.9%
Haggitt Classification Level 0: noninvasive (severe dysplasia) Level 1: invading through the muscularis mucosa but limited to the head of a pedunculated polyp Level 2: invading the neck of a pedunculated polyp Level 3: invading the stalk of a pedunculated polyp Level 4: invading into the submucosa below the stalk of a pedunculated polyp ( Sessile malignant polyplevel 4 ) All sessile polyps with invasive cancer are level 4
Kikuchi Classification of Adenocarcinoma in Sessile Polyp Haggitt level 1,2,3 = Kikuchi Sm1 level 4 = Sm1, Sm2 or Sm3
Local Therapy Opportunity of cure with less detriment Staging is critical to management Histological Assessment Most important factor to predict risk of lymphatic spread Local Therapy Opportunity of cure with less detriment Tytherleigh et al. BJS 2008;95:409-423
Histopathological Features Low-risk ERC High-risk ERC Depth of wall invasion Haggitt 1-3 Kikuchi Sm1 & (possibly Sm2) Kikuchi Sm3 & (possibly Sm2) Grade Well Moderate differentiated Poorly differentiated Undifferentiated Lymphovascular invasion - + 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 Poorly differentiated 43% Goldstein et al. Am J Clin Pathol 1999;111:51-8 Depth: best estimate of the probability of regional LN metastasis Grade of initial bx may be diff from excised specimen Moderate 20% *Risk of LN metastasis vs sm1/2/3: Nascimbeni, Kikuchi *Nascimbeni et al. [15] studied histological specimens retrospectively from 353 patients undergoing colorectal resection for sessile T1 lesions.(1979-1995) The authors reported that the depth of invasion into the lower third of the submucosa (classified as ‘sm3’), the presence of lymphovascular invasion, and lesions in the lower third of the rectum were significant predictors of lymph node metastasis *(St Marks) S. Rasheed et al. Colorectal Disease, 10, 231–237. (1971-96)total 313 T1 in 55 (18.2%) and T2 in 248 (81.2%). The node positive group did however contain a significantly higher number of patients with poorly differentiated tumours (P = 0.001) and patients with evidence of extramural vascular invasion (P = 0.002). Finally there was no significant difference in the number of patients with sm1, sm2, sm3(12-14%), or T2 (~19%) tumour depths within the lymph node positive and negative groups Limitation: small sample size of T1, retrospective, surgeon choose for radical excision rather than local excision
Clinical Scenario 1. Post Colonoscopic polypectomy of rectal polyp Colonoscopy: 2.5cm rectal polyp (3cm from anal verge) Biopsy: adenocarcinoma 2. Post Colonoscopic polypectomy of rectal polyp Pathology: adenocarcinoma arise from tubular adenoma
Clinical Scenario 1. Colonoscopy: 2.5cm rectal polyp (3cm from anal verge) Biopsy: adenocarcinoma
Scenario 1 2.5cm rectal Polyp Digital rectal exam ERUS MRI CT LN + LN - Radical Sx AR/TME/APR T2 T1 Local Excision + Adj ChemoRT High Risks Features Sm3 (Sm2) Grade lymphovascular No High Risks Features Follow-up Recurrence No Recurrence Salvage Surgery APR for an ERC should be unusual as there are many sphincter-preserving techniques that can be empolyed Pt’s choice, co-morbidity, body habitus will also affect tx decision Local excision + adj chemoRT for T2 and high risk T1: assuming that further surgery is not an option
ERUS Best method to determining T stage T stage N stage Accuracy: 90 % Sensitivity : 85% Specificity: 95% N stage Accuracy: 80% Sensitivity: 70% Specificity: 80% hypoechoic nodes with short axis diameters of 5 mm or more, nodes of any diameter with heterogeneous echogenicity, or hypoechoic nodes of any diameter in cases with biopsy-proven Bretagnol et al. Dis Colon Rectum 2007;50:523-533
ERUS T1-slight (Sm1) detection Sensitivity (99%) Specificity (74%) Accuracy (96%) Akasu et al. World J Surg 2000;24:1061-1068 May assess residual tumour following polypectomy Follow up after local excision or radical surgery Hernandez De Anda et al. Dis Colon Rectum 2004; 47: 818–824 Limitations Sm1 Operator dependent Tumor height Tumour stenosis Peritumoral fibrosis and inflammatory tissue Effect of pre op radiotherapy or haemorrhage in bowel wall after bx Sensitivity/specificity/overall accuracy rates for detection of slight submucosal invasion, massive submucosal invasion, and muscularis propria invasion were 99%/ 74%/96%, 98%/88%/97%, and 97%/93%/96%, respectively Limitations: peritumoral fibrosis and inflammatory tissue, operator dependent, tumor height, tumour stenosis, effect of pre op radiotherapy or haemorrhage in bowel wall after bx -the substitution of the typical five-layer structure of the rectal wall by a mixed echoic pattern involving a segment of the rectal wall. The staples after an anastomosis are usually visualized as a circumferential line of small, bright echoes without a shadow. Local recurrence often appears as a well-defined hypoechoic homogenous mass involving the rectal wall or as a hypoechoic extrarectal node, persisting in at least two consecutive exams (Figs. 1 and 2). Recurrence was confirmed by endoscopic biopsy, ultrasound-guided biopsy, or CT scan-guided biopsy. Sm2
MRI Overall T stage accuracy 59-95% T1,2 lesion (vs ERUS) N stage Similar sensitivities Lower specificity (69%) N stage Comparable vs ERUS Endorectal and phased-array coils--> better resolution and accuracy for predicting tumour stage New techniques accuracy ~ 90% A meta analysis: T1, 2 lesion: ERUS, MRI smilar sensitivities, ERUS 86% specificity sig higher MRI69% Bretagnol et al. Dis Colon Rectum 2007;50:523-533
Scenario 1 2.5cm rectal Polyp Digital rectal exam ERUS MRI CT LN - LN + T1 T2 Local Excision High Risks Features Sm3 (Sm2) Grade lymphovascular No High Risks Features APR for an ERC should be unusual as there are many sphincter-preserving techniques that can be empolyed Pt’s choice, co-morbidity, body habitus will also affect tx decision Local excision + adj chemoRT for T2 and high risk T1: assuming that further surgery is not an option Follow-up Local Excision + Adj ChemoRT Radical Sx AR/TME/APR Recurrence No Recurrence Salvage Surgery
Local Excision Potential advantage Sphincter preservation Minimal mortality and morbidity Low urinary/sexual dysfunction risk
Local Excision Parks’ Per Anal Excision Lesions 6-10cm from anal verge Aid of anal retractors Full thickness excision Transanal Endoscopic Microsurgery Resectoscope Usual below peritoneal reflection Snare polypectomy or endoscopic mucosal resection is used to treat polyps that are thought to be benign. A polyp that does not ‘lift’ on submucosal infiltration should be regarded as malignant ???peritoneal reflection
Local Excision LR Bretagnol et al. Dis Colon Rectum 2007;50:523-533
Local Excision vs Radical Sx T1sm3 lesion Radical Surgery had lower rates of distant metastasis and better survival Bretagnol et al. Dis Colon Rectum 2007;50:523-533 NASCIMBENI ET AL Dis Colon Rectum 2004; 47: 1773–1779 We compared 70 patients who underwent local excision with 74 patients who underwent oncologic resection. Among patients with lesions in the middle or lower third of the rectum, 1) the five-year and ten-year outcomes were significantly better for overall survival and cancer-free survival in the oncologic resection group, but there were no significant differences in local recurrence or distant metastasis; 2) the multivariate risk factors for long-term, cancer-free survival were invasion into the lower third of the submucosa, local excision, and older than aged 68 years; and 3) for lesions with invasion into the lower third of the submucosa, the oncologic resection group had lower rates of distant metastasis and better survival. Among patients with lesions in the lower third of the rectum, 1) the five-year and tenyear outcomes showed no significant differences in survival, local recurrence, or distant metastasis between the two groups; and 2) for lesions with invasion into the lower third of the submucosa, the oncologic resection group showed a trend of improved survival, which was not statistically significant, possibly because of low statistical power from the small sample size
Scenario 1 2.5cm rectal Polyp Digital rectal exam ERUS MRI CT LN - LN + T1 T2 Local Excision High Risks Features Sm3 (Sm2) Grade lymphovascular No High Risks Features APR for an ERC should be unusual as there are many sphincter-preserving techniques that can be empolyed Pt’s choice, co-morbidity, body habitus will also affect tx decision Local excision + adj chemoRT for T2 and high risk T1: assuming that further surgery is not an option Follow-up Local Excision + Adj ChemoRT Radical Sx AR/TME/APR Recurrence No Recurrence Salvage Surgery
Adjuvant chemoradiotherapy Limited data May be helpful If further surgery is not an option T1 lesions with adverse pathologic features T2 lesions (Tytherleigh et al. BJS 2008;95:409-423) Difficult to interpret Most retrospective studies Lack of controlled data Adjuvant regime not always based on a defined protocol Difficult to interpret Most series retrospective studies with heterogeneous gp of pt n lack of controlled data adjuvant regime is not always based on a defined protocol In conclusion, the limited data suggest that adjuvant chemoradiotherapy may be helpful in patients with T1 lesions with adverse pathologic features and T2 lesions, achieving a local recurrence rate < 20 percent. Bretagnol et al. Dis Colon Rectum 2007;50:523-533
Scenario 1 2.5cm rectal Polyp Digital rectal exam ERUS MRI CT LN - LN + T1 T2 Local Excision High Risks Features Sm3 (Sm2) Grade lymphovascular No High Risks Features APR for an ERC should be unusual as there are many sphincter-preserving techniques that can be empolyed Pt’s choice, co-morbidity, body habitus will also affect tx decision Local excision + adj chemoRT for T2 and high risk T1: assuming that further surgery is not an option Follow-up Local Excision + Adj ChemoRT Radical Sx AR/TME/APR Recurrence No Recurrence Salvage Surgery
Follow up Regular endoscopic surveillance of rectum and scar Digital rectal exam + Endoscopy + CEA First 2 years: every 3 months Next 3 years: every 6 months Then annually National comprehensive Cancer Network guidelines recommended for T1 with local excision Q3m x 2yr Q6m x 3 yr q1y Mellgren et al. Dis Colon Rectum 2000; 43: 1064–1071 NCCN guideline
Follow up ERUS Advisable Frequency: subject to debate One study showed More isolated local recurrence in the follow-up ERUS group underwent Salvage Surgery (44% vs 23 %), but the differences were not significant Hernandez De Anda et al. Dis Colon Rectum 2004; 47: 818–824 ERUS every four months for the first three years and every six months for the two years after curative surgery
Scenario 1 2.5cm rectal Polyp Digital rectal exam ERUS MRI CT LN - LN + T1 T2 Local Excision High Risks Features Sm3 (Sm2) Grade lymphovascular No High Risks Features APR for an ERC should be unusual as there are many sphincter-preserving techniques that can be empolyed Pt’s choice, co-morbidity, body habitus will also affect tx decision Local excision + adj chemoRT for T2 and high risk T1: assuming that further surgery is not an option Follow-up Local Excision + Adj ChemoRT Radical Sx AR/TME/APR Recurrence No Recurrence Salvage Surgery
Recurrence Long-term FU beyond 10 years is necessary Unresected disease in regional lymphatics cause local failure Diagnose early for salvage surgery Tytherleigh et al. BJS 2008;95:409-423
Salvage Surgery 56-100% of patients with recurrence suitable for salvage surgery Results controversial May not afford same outcomes as initial classical treatment Decreased survival if resection is delayed at time of recurrence (for adverse pathology of local excision specimen) Disease free survival rates 20-35% Mellgren et al. Dis Colon Rectum 2000; 43: 1064–1071
Clinical Scenario 2. Colonoscopic polypectomy of rectal polyp Pathology: adenocarcinoma arise from tubular adenoma
Scenario 2 Post polypectomy (Adenoca arise from TA) No High Risks Features Haggitt level 1,2,3 Kikuchi Sm1 High Risks Features Sm3 (Sm2) Grade lymphovascular ERUS MRI CT LN- LN+ Margin involvement Yes Histological assessment not adequate No Local Excision No Yes Follow up Radical Surgery High Risks Features
Summary Staging and Adequate Histological Assessment is crucial in management of malignant rectal polyp
Summary Local excision Radical Surgery Recurrence Recommended for low risk T1 sm1 lesion Adjuvant therapy considered in high risk T1, T2 if surgery not an option Radical Surgery Recommended for high risk T1 , T2 lesion Recurrence Diagnose early for salvage surgery
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