Management of malignant colonic polyps: a population-based analysis of colonoscopic polypectomy versus surgery

Abstract

Background: The management of colon polyps containing invasive carcinoma includes surgical resection or colonoscopic polypectomy. To date, there are very limited population-based data comparing outcomes with the 2 management approaches.

Methods: Using the linked Surveillance Epidemiology and End Results-Medicare database, we identified 2077 patients aged ≥66 years with an initial diagnosis of stage T1N0M0 malignant polyp from 1992-2005. Patients were categorized as surgical or polypectomy depending on the most invasive treatment. To adjust for potential selection bias in treatment assignment, using multivariate analysis, patients were divided into quintiles of likelihood of polypectomy (propensity scores), and outcomes were compared in each quintile.

Results: Surgical resection was performed in 1340 (64.5%) patients and polypectomy was performed in 737 (35.5%) patients. Predictors for undergoing polypectomy (P<.001) included older age, greater comorbidity, no history of polyps, diagnosis in 2002 or later, left colon site of cancer, well-differentiated tumors, and colonoscopy performed in an outpatient setting. Both 1-year and 5-year survival were higher in the surgical group (92% and 75%, respectively) than in the polypectomy group (88% and 62%, respectively). The unadjusted hazard ratio was 1.51 (95% confidence interval [CI], 1.31-1.74). After adjusting for propensity quintile, the hazard ratio was 1.15 (95% CI, 0.98-1.33). Within each propensity quintile, the risk of death was similar between the 2 groups (interaction test P = .96).

Conclusions: In this large, population-based sample, more than one-third of patients with malignant polyps were treated with colonoscopic polypectomy. Outcomes were similar to surgical patients with comparable clinical characteristics and could be offered to patients who meet appropriate clinical criteria.

Copyright © 2011 American Cancer Society.

Figures

Figure 1

Long-term survival among 2,077 patients with malignant polyps treated with surgical resection or colonoscopic polypectomy. In unadjusted analysis, survival was improved among patients treated surgically (log rank p

Figure 2

Long-term survival in patients with malignant polyps treated with surgical resection (solid lines) or colonoscopic polypectomy (dashed lines), stratified by propensity quintile. Data are shown for the quintile least likely to undergo polypectomy (panel a) through most likely (panel e). Within each quintile, survival did not differ between groups (log rank p=0.21 quintile 1; p=0.50 quintile 2; p=0.41 quintile 3; p=0.71 quintile 4; p=0.33 quintile 5).