Publication Abstract

Authors: Sundararajan V, Mitra N, Jacobson JS, Grann VR, Heitjan DF, Neugut AI

Title: Survival associated with 5-fluorouracil-based adjuvant chemotherapy among elderly patients with node-positive colon cancer.

Journal: Ann Intern Med 136(5):349-57

Date: 2002 Mar 05

Abstract: BACKGROUND: Randomized clinical trials have demonstrated the efficacy of adjuvant 5-fluorouracil (5-FU)-based chemotherapy after surgical resection of node-positive colon cancer. Although this treatment became the standard in 1990 following a National Institutes of Health Consensus Conference, among those at least 65 years of age it is less likely to be offered to older or nonwhite patients. OBJECTIVE: To determine the association between 5-fu-based chemotherapy and survival in older patients. DESIGN: Retrospective cohort study. SETTING: Combined database of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program and Medicare. PATIENTS: 4768 patients 65 years of age or older who received a diagnosis of node-positive colon cancer from 1992 to 1996, were covered by Medicare Parts A and B, and resided in the population covered by the SEER program. MEASUREMENTS: Propensity scores to control for known predictors of receiving treatment, Cox proportional hazards models to assess the association of 5-FU therapy with survival, and sensitivity analyses to estimate the possible effects of unknown confounders. RESULTS: Fifty-two percent of patients received 5-FU therapy. For this sample, the hazard ratio for death associated with 5-FU therapy was 0.66 (95% CI, 0.60 to 0.73). Confounding could have accounted for this association only if an unmeasured confounder were extremely unequally distributed between the treated and untreated groups or increased mortality by at least 50%. CONCLUSIONS: 5-Fluorouracil adjuvant therapy is significantly associated with reduced mortality in older patients, similar to the association found in randomized, controlled trials among younger patients. More frequent use of 5-FU therapy in older patients would probably reduce death from colon cancer.