Safety and Effectiveness of Oxaliplatin-Based Chemotherapy Regimens in Adults 75 Years and Older With Colorectal Cancer

BackgroundAlthough the safety and efficacy of oxaliplatin-based chemotherapy regimens for colorectal cancer (CRC) have been demonstrated in adults ≥ 75 years of age who are enrolled in clinical trials, safety and effectiveness outside the trial setting are less established.MethodsWe retrospectively collected cases of patients ≥ 75 years of age who were diagnosed with stage III and metastatic CRC and initiated treatment between January 2000 and January 2007 at 2 academic hospitals in Boston, MA. Cases were matched in a 1:2 ratio to controls who were < 75 years of age by hospital site, stage of disease (stage III vs. metastatic) and line of therapy (first- or second-line or beyond). The primary study endpoints were grade ≥ 3 treatment-associated toxicities and intolerance (number of dose delays/reductions and hospital/facility admissions during treatment). The secondary endpoint was overall survival.ResultsWe identified 84 patients ≥ 75 years of age (25% ≥ 80 years) and 168 controls. In the cohort, 77% had colon cancer, 75% had metastatic disease, and 60% were receiving oxaliplatin as first-line therapy. There was no significant difference in grade ≥ 3 treatment-associated toxicities between the patients and the controls (71.4% vs. 68.5%, respectively; P = .63). Further there was no statistically significant difference between patients and controls for combined endpoints of any grade ≥ 3 toxicity or hospital/facility admission (P = .92). With a median follow-up of 52 months, 2-year overall survival was similar between patients and controls (43% vs. 52%, respectively; P = .87).ConclusionOlder adults with stage III and metastatic CRC treated outside of a clinical trial experienced safety and effectiveness of oxaliplatin-based chemotherapy regimens that was comparable to that of younger adults.