Malignant Rectal Polyp
Dr Kit-wai Lai
Department of Surgery
Tuen Mun Hospital
Joint Hospital Surgical Grand Round 18 Apr 2009
Malignant Rectal Polyp
• Polyps with cancer cells penetrating the muscularis mucosa
• Invasion limited to submucosa
• i.e. T1 lesion
Malignant?Malignant?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%
• Level 0: noninvasive (severe dysplasia)
• Level 1: invading through the muscularis mucosa but limited to the headhead of a pedunculated polyp
• Level 2: invading the neckneck of a pedunculated polyp
• Level 3: invading the stalkstalk of a pedunculated polyp
• Level 4: invading into the submucosa below the stalkbelow the stalk of a pedunculated polyp
( Sessile malignant polyplevel 4 )
Haggitt Classification
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
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
- +
Poorly differentiated 43%Goldstein et al. Am J Clin Pathol 1999;111:51-8
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
Clinical Scenario2.
• Post Colonoscopic polypectomy of rectal polyp
• Pathology: adenocarcinoma arise from tubular adenoma
1.
• Colonoscopy: 2.5cm rectal polyp (3cm from anal verge)
• Biopsy: adenocarcinoma
Clinical Scenario
1.
• Colonoscopy: 2.5cm rectal polyp (3cm from anal verge)
• Biopsy: adenocarcinoma
Scenario 12.5cm rectal Polyp Digital rectal exam
ERUS MRI CT
LN + LN -
Radical Sx
AR/TME/APR
T2 T1
Local Excision+ Adj ChemoRT
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Local Excision
Follow-up
Recurrence No RecurrenceSalvage Surgery
ERUS
• Best method to determining TT stagestage
T stage Accuracy: 90 %
Sensitivity : 85%
Specificity: 95%
N stageAccuracy: 80%
Sensitivity: 70%
Specificity: 80%
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
•Operator dependentOperator dependent
•Tumor heightTumor height
•Tumour stenosisTumour stenosis
•Peritumoral fibrosis and inflammatory tissuePeritumoral fibrosis and inflammatory tissue
•Effect of pre op radiotherapy or haemorrhage in Effect of pre op radiotherapy or haemorrhage in bowel wall after bxbowel wall after bx
Sm1
Sm2
MRI
• Overall T stage accuracy 59-95%
• T1,2 lesion (vs ERUS)– Similar sensitivities– Lower specificity (69%)
• N stage– Comparable vs ERUS
Bretagnol et al. Dis Colon Rectum 2007;50:523-533
Scenario 12.5cm rectal Polyp Digital rectal exam
ERUS MRI CT
LN +LN -
Radical Sx
AR/TME/APR
T2 T1
Local Excision+ Adj ChemoRT
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Local Excision
Follow-up
Recurrence No RecurrenceSalvage 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
– Full thickness excision
Local Excision
Bretagnol et al. Dis Colon Rectum 2007;50:523-533
LR
Local Excision vs Radical Sx
Bretagnol et al. Dis Colon Rectum 2007;50:523-533T1T1sm3sm3 lesion lesion
Radical Surgery had lower rates of
distant metastasis and better survival
Scenario 12.5cm rectal Polyp Digital rectal exam
ERUS MRI CT
LN + LN -
Radical Sx
AR/TME/APR
T2 T1
Local Excision+ Adj ChemoRT
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Local Excision
Follow-up
Recurrence No RecurrenceSalvage Surgery
Adjuvant chemoradiotherapy
Bretagnol et al. Dis Colon Rectum 2007;50:523-533
Difficult to interpretDifficult to interpret
Most retrospective studies Most retrospective studies
Lack of controlled dataLack of controlled data
Adjuvant regime not always based on a defined protocolAdjuvant regime not always based on a defined protocol
Limited dataLimited data
May be helpful May be helpful
If further surgery is not an option If further surgery is not an option
T1 lesions with adverse pathologic features T1 lesions with adverse pathologic features
T2 lesionsT2 lesions (Tytherleigh et al. BJS 2008;95:409-423)
Scenario 12.5cm rectal Polyp Digital rectal exam
ERUS MRI CT
LN +LN -
Radical Sx
AR/TME/APR
T2 T1
Local Excision+ Adj ChemoRT
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Local Excision
Follow-up
Recurrence No RecurrenceSalvage 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
Mellgren et al. Dis Colon Rectum 2000; 43: 1064–1071NCCN 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
Scenario 12.5cm rectal Polyp Digital rectal exam
ERUS MRI CT
LN +LN -
Radical Sx
AR/TME/APR
T2 T1
Local Excision+ Adj ChemoRT
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Local Excision
Follow-up
Recurrence No RecurrenceSalvage 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)
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)
Radical Surgery Follow up
ERUS MRI CT
LN+
High Risks FeaturesSm3 (Sm2)Gradelymphovascular
No High Risks Features
Haggitt level 1,2,3
Kikuchi Sm1
Margin involvement
Yes
Local Excision
Histological assessment not adequate
No
High Risks FeaturesNoYes
LN-
Summary
StagingStaging and
Adequate HistologicalAdequate Histological AssessmentAssessment
is crucial in management of malignant
rectal polyp
Summary
• Local excisionLocal excision
Recommended for low risk T1 sm1 lesion
Adjuvant therapy considered in high risk T1, T2 if surgery not an option
• Radical Surgery Radical Surgery Recommended for high risk T1 , T2 lesion
• Recurrence Recurrence
Diagnose early for salvage surgery
Thank YouThank You