Malignant Rectal Polyp

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


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%


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



ERUS MRI CT

LN +LN -

Radical Sx

AR/TME/APR

T2 T1




Local Excision

Follow-up


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


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


ERUS MRI CT

LN + LN -

Radical Sx

AR/TME/APR

T2 T1




Local Excision

Follow-up


Adjuvant chemoradiotherapy


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)


ERUS MRI CT

LN +LN -

Radical Sx

AR/TME/APR

T2 T1




Local Excision

Follow-up


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


ERUS MRI CT

LN +LN -

Radical Sx

AR/TME/APR

T2 T1




Local Excision

Follow-up


Recurrence

• Long-term FU beyond 10 years is

necessary

• Unresected disease in regional lymphatics

cause local failure

• Diagnose early for salvage surgery


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+



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

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Malignant Rectal Polyp