Cancer risk in endoscopically unresectable colon polyps

Area of Science:

• Gastroenterology
• Surgical Oncology
• Colorectal Surgery

Background:

• Endoscopic resection is standard for polyps, but some are unresectable.
• The malignancy rate in unresectable polyps requires definition.

Purpose of the Study:

• To determine the rate of underlying malignancy in endoscopically unresectable polyps.
• To identify risk factors associated with malignancy in these polyps.

Main Methods:

• Retrospective review of patients undergoing colectomy for unresectable polyps (1997-2006).
• Inclusion criteria: adenomatous polyp without invasive cancer on initial biopsy.
• Data abstracted included patient demographics, polyp characteristics, and outcomes.

Main Results:

• 16% of patients (13/80) had invasive cancer in surgical specimens.
• No significant association between polyp size or histology and invasive cancer.
• Polyps distal to the splenic flexure were more likely to harbor malignancy (OR 1.38).
• Surgical morbidity was 37% with 3% in-hospital mortality.

Conclusions:

• The cancer risk in unresectable polyps is lower than previously suggested.
• Polyp location distal to the splenic flexure is a risk factor for occult malignancy.
• Neither polyp size nor histology predicts malignancy in these cases.