Efficacy and safety of oral 5-FU-based adjuvant chemotherapy for geriatric patients with colorectal cancer: Integrated analysis of seven clinical trials conducted at the Japanese Foundation for Multidisciplinary Treatment of Cancer.

Abstract

Adjuvant chemotherapy after radical resection is recommended for patients with high-risk Stages II and III colorectal cancer (CRC). However, the efficacy and safety of adjuvant chemotherapy in geriatric patients require elucidation. We analysed data from seven clinical trials conducted by the Japanese Foundation for the Multidisciplinary Treatment of Cancer. Survival curves were estimated using the Kaplan-Meier method and compared using the log-rank test. Survival analysis was performed using a Cox proportional hazards model. This study included 7756 non-geriatric (<70 years) and 1706 geriatric patients (≥70 years). Adjuvant chemotherapy significantly improved the 5-year overall survival in non-geriatric patients (81.6% vs. 73.6%, p < 0.001) but did not significantly improve the survival rate in geriatric patients (78.9% vs. 76.1%, p = 0.129). However, adjuvant chemotherapy was effective for N+ geriatric patients (hazard ratio, 0.48; 95% confidence interval, 0.35-0.66; p < 0.001). Adverse events associated with adjuvant chemotherapy were significantly more frequent in geriatric than in non-geriatric patients. Adjuvant chemotherapy in geriatric patients with node-positive CRC was as effective as in non-geriatric patients, although no benefit was shown in geriatric patients with node-negative CRC. More adverse events were observed in geriatric patients than in non-geriatric patients.