Transcript Treatment of Early Malignant Rectal Polyp

Dr KP Tsui
Department of Surgery
Tseung Kwan O Hospital
Malignant Rectal Polyp
 Polyps with cancer cells invading the muscularis
mucosa
 Invasion 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 1
 Colonoscopy: 2 cm rectal polyp (5 cm
from anal verge)
 Biopsy: adenocarcinoma
Endorectal ultrasound
 Best method to differentiate between T1 and T2 lesion

T stage
Accuracy: 90 %
Sensitivity : 85%
Specificity: 95%
N stage
Accuracy: 80%
Sensitivity: 70%
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
Limitations
 Operator dependent
 Upper rectal lesions
 Tumor stenosis
 Peritumoral fibrosis and inflammatory tissue
 Effect of radiotherapy or hemorrhage after biopsy
Pelvic MRI
 Overall 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;50:523-533
Tytherleigh et al. BJS 2008;95:409-423
CT abdomen + pelvis
 Distant metastases
 Low 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 1
Bretagnol et al. Dis Colon Rectum 2007;50:523-533
PET
 Limited role for local and regional staging
 Sensitivities for lymph node metastases 22-29%
Abdel-Nabi H, Doerr RJ, Lamonica DM, et al. Radiology.
1998;206:755-760
Surgical Options
Local excision
vs
Radical Surgery
Park’s per anal excision
Abominoperineal resection
TEM
Total Mesorectal Excision
Anterior resection
Local Excision
 Opportunity 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 microsurgery
 Rectoscope
 Usually below peritoneal reflection
 Full thickness excision
 Excision margin of 1 cm
 Difficult for lesions within 6 cm
Long-handled transanal endoscopic
microsurgery instrument
Complications
 Overall 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 Features
Low 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 1-3
Kikuchi Sm 1 and ?Sm2
Kikuchi Sm3 and ?Sm2
Positive 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 surgery
 The 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 chemoradiotherapy
 May 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
Limitations
 Most retrospective studies
 Lack of controlled data
 No defined protocol for chemotherapy
Salvage surgery
 Between 56 and 100% of recurrence suitable for salvage
surgery
 May not offer same outcomes as initial treatment
 Should not be delayed in case of recurrence
Tytherleigh et al. BJS 2008;95:409-423
Clinical Scenario 2
 Colonoscopic polypectomy of rectal polyp
 Pathology: adenocarcinoma
Pathology
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
Radical Surgery
Yes
High Risks Features
No
Follow up
Follow up
 Digital rectal exam + Endoscopy + CEA
First 3 years: every 3 months
Next 2 years: every 6 months
Then annually
 Endorectal ultrasound should be performed at every
outpatient session
Mellgren et al. Dis Colon Rectum 2000; 43: 1064–1071
NCCN guideline
Summary
 Local excision
Recommended for low risk T1 Sm1 lesion
 Radical 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