1. Polyps – Where do they come from and what do you do with them?!
Ron G. Landmann, MD
Grand Rounds
Department of Surgery
St. Luke’s-Roosevelt Hospital Center
March 21, 2007

2. Polyps Cancer epidemiology Definition of the malignant polyp
Natural history of adenomatous polyps
Biology of polyps
The anatomy of the polyp
Correlations with Malignancy
Endoscopic polypectomy alone???
Special considerations
* No discussion of technique

3. Colorectal Cancer – Epidemiology
Incidence: Approx. 150,000 cases/year
Deaths: Approx. 50,000 deaths/year
At diagnosis
10% in situ disease
30% local disease
30% regional disease
30% distant disease
5 year survival, all patients: 50%
local - 90%
regional - 60%
distant - 5%
U.S. Cancer Statistics Working Group. United States Cancer Statistics: 2003 Incidence and Mortality (preliminary data). Atlanta (GA): Department of Health and Human Services, Centers for Disease Control and Prevention, and National Cancer Institute; 2006.

4. Incidence/Prevalence of Polyps
Adenomatous polyps
30% of Western population
Most cancers arise from polyps
*excludes syndromes

5. Carcinoma in situ vs. cancer
 Think
Carcinoma in situ = high grade dysplasia
Carcinoma in situ ≠ cancer
Histology
Colorectal cancer is defined by invasion of/through muscularis mucosa

6. Colorectal cancer is defined by invasion of muscularis mucosa
Histology
Colorectal cancer is defined by invasion of muscularis mucosa
Lymphatics are located in submucosa
Genetic model of colorectal tumorigenesis

7. Colon Cancer Staging T-stage Tis
Intraepithelial or invasion of lamina propria T1
Invades submucosa T2
Invades muscularis propria T3
Invades subserosa or pericolic/rectal tissues T4
Into other organs/perforates visceral peritoneum
N-stage
0 LN 1
1-3 positive LNs 2
> 3 positive LNs

8. Colon Cancer Staging AJCC 5 Stage T N M 5 year DSS (%) Colon Rectum
Tis I
1-2 75 70 II
3-4 65 55
III
Any 45 40 IV 1 5

9. Relationship Between TNM Stage and Survival in Colorectal Carcinoma
CA Cancer J Clin 2004;54;

10. Treatment of CRC  Pathology is key! Polypectomy Colonic Resection
Treatment depends on the risk of lymph node metastasis.
 Pathology is key!
Colorectal cancer is defined by invasion of muscularis mucosa
Lymphatics are located in submucosa

11. Incidence of malignant polyps
Definition
Malignant polyps or T1 lesions (limited to the submucosa)
Represent 5% of all adenomas
Colonoscopy polypectomy series: 2 – 12%
Colorectal resection series: 4 – 9%

12. Haggitt Level (1985) Classification of polyps with invasive cancer
Definition
Resected (N)
+ LN (N)
Carcinoma in situ 1
Invasion of head 6
0 (< 1%) 2
Invasion of neck 3
Invasion of stalk 4
Invasion of submucosa of bowel wall below polyp 13
4 (31%, %)
Haggitt RC, Glotzbach RE, Soffer EE, Wruble LD. Prognostic factors in colorectal carcinoma arising in adenomas: Implications for lesions removed by endoscopic polypectomy. Gastroenterology 89:328-36, 1985, p 330.
Villuous/sessile (flat) polyps with invasive cancer are by definition Haggitt 4.

13. Sessile Polyps Kudo, 1993
Risk of lymph node metastasis in each sessile lesion is not the same
Haggitt’s: no detail for sessile lesions
Classification of submucosal invasion:
Sm1—Invasion into the upper third of the submucosa
Sm2—Invasion into the middle third of the submucosa
Sm3—Invasion into the lower third of the submucosa
High rate of LN metastasis: 12-25%

14. Sm system Able to determine Sm1, Sm2, Sm3 in 97% of cases
Haggitt Level 1, 2, 3 = Sm1
Haggitt Level 4 = Sm1, Sm2, or Sm3
Endoscopist must properly resect and prepare specimen
Pathologist must properly section and examine all layers

15. Correlations with Malignancy Morphology
Incidence
% Malignant
Tubular 75 5
Tubulovillous 15 20
Villous 10 40

16. Correlations with Malignancy Grade
Dysplasia
% malignant
Mild 5
Moderate 20
Severe 30

17. Correlations with Malignancy Size
Size (cm)
% malignant
< 1 1
1 – 2 10
≥ 2 50
Muto, 1975

18. Correlations with Malignancy Size
Size (cm)
% malignant
< 1 1
1 – 2 10
≥ 2 50
Size (cm)
% malignant
≤ 0.5
Negligible
0.6 – 1.5 2
1.6 – 2.5 19 43
≥ 3.5 76
Muto, 1975
Nusco, 1997

19. Relationship between Size and Morphology
Tubular
Tubulovillous
Villous
< 1 cm
76%
25%
14%
1-2cm
20%
47%
26%
> 2 cm 4%
28%
60%
St. Mark’s Hospital Data

20. Increased risk of LN Metastasis
Unfavorable pathologic features of malignant CR polyps
Poor differentiation (only on univariate)
Lymphovascular invasion (P < 0.009)
Invasion below submucosa (Haggitt Level 4)
Depth of invasion in Sm3 (P < 0.001)
Site in lower 1/3 of the rectum (P < 0.001)
Positive resection margin (< 1 mm or 1 HPF)
Not really – this is inadequate treatment, not an adverse risk factor!
P-values from Nascimbeni et al. N = 353 T1 colorectal sessile lesions

21. Management of Pedunculated Malignant Polyps
Haggitt Level 1, 2, 3
Complete excision or snaring
Risk of LN metastasis < 1%
Haggitt Level 4
Treat as sessile lesions

22. Management of Sessile Malignant Polyps
< 2cm in diameter
Adequate snare in one piece via colonoscopy
Requires microscopic free margin of at least 2mm
Piecemeal removal
Requires further excision/follow-up or resection
High risk factors (LVI, Sm3, distal 1/3 rectum)
Oncologic resection
Full thickness transanal excision

23. Lesions amenable to colonoscopic polypectomy
Pedunculated or sessile < 2cm
Well/moderately differentiated
No lymphovascular invasion
Haggitt Level 1-3 or Sm1
Close follow-up available
Endoscopically complete excision
Negative resection margins (2mm)

24. Criteria for Treatment of Malignant CR Polyps by Polypectomy Alone
Determined by risk of metastasis
Low risk of Lymph Node Metastasis
Pedunculated
Haggitt Level 1, 2, 3
Level 4 Sm1, Sm2
Sessile
Sm1, Sm2
High risk of Lymph Node Metastasis
Lower 1/3 of the submucosa (Sm3)
LVI
Distal 1/3 of rectum

25. Malignant Colorectal Polyps that Should have an Oncologic Bowel Resection
Lesions in colon
Pedunculated Haggitt Level 4 with invasion into distal third of submucosa (Sm3) or LVI
Sessile lesions removed with margin < 2mm
Sessile lesions removed piecemeal
Sessile lesions with depth of invasion into distal third of submucosa (Sm3)
Sessile lesions with LVI
Lesions in middle third and upper third rectum
Same as lesions in colon
Lesions in distal third rectum
Pedunculated Haggitt Level 4 with invasion into distal third of submucosa (Sm3) or pedunculated lesions with LVI
All sessile lesions

26. Why not just resect anyway?!

27. What if ??? What if it’s clipped in ½?
Pedunculated
Repeat endoscopy.
Require good resection with margin (2mm)
Sessile
Requires operative oncologic resection (even if Sm1, Sm2)
Unable to determine exact pathologic depth
What if it’s shredded by forceps?
Requires operative oncologic resection
What if it’s a very small lesion?
Requires marking/tattoo CIRCUMFERENTIALLY
What if it’s carcinoma in situ?
It’s not cancer. This is high grade dysplasia. Requires close follow-up.
Unless,
poor margins: repeat endoscopy with good margins
Piecemeal resection: discussion with pathologist and patient
What if it’s a large, non-endoscopically resectable polyp?
Repeat endoscopy (2nd MD?)
Oncologic resection

28. Other considerations…
When in doubt
Repeat colonoscopy (endoscopy)
Personally review pathology
Get a second opinion
Have a frank discussion with patient

30. Polyps Natural history of adenomatous polyps Biology of polyps
Cancer epidemiology
The anatomy of the polyp
Correlations with Malignancy
Endoscopic polypectomy alone???
Special considerations
Indications for Polypectomy
What if it’s clipped in ½
What if it’s shredded by forceps?
Pathology…
Marking/tattoo
Chances of Malignancy by histopath and size/morphology
* NO technique **