Colonoscopic Polypectomy: Long-Term Benefit in Preventing Colon Cancer Deaths

A multi-institutional, NCI-funded retrospective study in the New England Journal of Medicine highlights the significant long-term benefit of colonoscopic polypectomy in preventing death from colon cancer, with polypectomy cutting the incidence of colon cancer–related mortality in half compared with the general population.

Identification and removal of a pedunculated colonic polyp at colonoscopy; source: Gilo1969, Wikimedia Commons

For the study, Ann G. Zauber, PhD, from the department of epidemiology and biostatistics at Memorial Sloan-Kettering Cancer Center, and coauthors aimed to evaluate the long-term effect of colonoscopic polypectomy on mortality from colorectal cancer, by following patients from the National Polyp Study (NPS), which showed removal of adenomatous polyps during colonoscopy prevented colorectal cancer.

Included in the NEJM study, published in the February 23 issue, were all patients prospectively referred for initial colonoscopy (between 1980 and 1990) at NPS clinical centers who had adenomas and nonadenomas. (Patients with nonadenomatous polyps served as the internal control group.)

Using the National Death Index to identify deaths and their causes during a follow-up period as long as 23 years, Dr. Zauber and coauthors assessed mortality from colorectal cancer among patients with adenomas removed, compared with patients who had nonadenomatous polyps and with the expected incidence-based mortality from colorectal cancer in the general population (using data from the Surveillance Epidemiology and End Results [SEER] Program).

After a median of 15.8 years, of 2,602 NPS patients who had adenomas removed, 1,246 had died from any cause and 12 had died from colorectal cancer. “Given an estimated 25.4 expected deaths from colorectal cancer in the general population, the standardized incidence-based mortality ratio was 0.47 (95% CI, 0.26–0.80) with colonoscopic polypectomy, suggesting a 53% reduction in mortality,” the investigators wrote.

During the first 10 years after polypectomy, they said, mortality from colorectal cancer was similar among patients with adenomas vs nonadenomatous polyps. In conclusion, they wrote that their study results “support the hypothesis that colonoscopic removal of adenomatous polyps prevents death from colorectal cancer.”