Oxaliplatin-Based Chemotherapy in Patients with Metastatic Colorectal Cancer Aged at Least 75 Years: A Post-Hoc Subgroup Analysis of Three Phase II Trials

Patients older than 75 years of age are usually excluded from metastatic colorectal cancer studies based on a combination chemotherapy containing oxaliplatin. Our group conducted three phase II trials in elderly patients in recent years. A post-hoc subgroup analysis of 67 patients aged at least 75 years was included in this study. Oxaliplatin was combined with capecitabine in two trials and with uracil-tegafur (UFT) plus folinic acid in the third trial. In one study, bevacizumab was also added to chemotherapy. The median age of patients was 77 years, and all had a good performance status (0 to 1). The observed overall response rate was 45%, comparable to younger patients (51%, p = 0.49). The estimated median progression-free survival (PFS) time and overall survival (OS) time were 8.7 and 19.3 months, respectively. These results did not significantly differ from those in younger patients (8.0 months for PFS (p = 0.58) and 19.7 months for OS (p = 0.94), respectively). The most common grade 3–4 adverse events included diarrhea (13%), fatigue (13%), peripheral neuropathy (10%), and neutropenia (7%). Moreover, the toxicity was never statistically different from that in younger patients. The efficacy of oxaliplatin-based combination was maintained in fit elderly patients ≥75 years.