Survival benefit of adjuvant chemotherapy in elderly patients with colon cancer: a systematic review and meta-analysis.

ABSTRACT

BACKGROUND: Adjuvant chemotherapy after curative resection is established as a standard therapy for colon and rectal cancer. Although the efficacy of adjuvant chemotherapy has been shown by pooled analyses from randomized controlled trials, elderly patients still receive adjuvant chemotherapy less frequently than younger patients. In this systematic review and meta-analysis, we aimed to assess the survival benefit of adjuvant chemotherapy in elderly patients based on observational studies in which the elderly patients would likely be representative of those encountered in real-world clinical settings. METHODS: A comprehensive literature search was conducted using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. Observational studies that investigated the survival benefit of adjuvant chemotherapy after curative resection in elderly patients (age ≥ 70 years) with colon or rectal cancer were included. The 5-year overall survival (OS) rate and OS were assessed. Risk of bias was assessed using the ROBINS-I tool. RESULTS: Eleven studies in elderly patients with colon cancer were included. No relevant study was identified for rectal cancer. Elderly patients who received adjuvant chemotherapy had a significantly higher 5-year OS rate than those who did not (risk ratio 1.51, 95% confidence interval 1.29-1.76, P < 0.001). There was also a significant improvement in OS in elderly patients who received adjuvant chemotherapy (hazard ratio 0.59, 95% confidence interval 0.53-0.66, P < 0.001). The overall risk of bias was judged to be critical for both outcomes. CONCLUSION: Adjuvant chemotherapy provides a survival benefit for elderly patients with colon cancer, although the quality of evidence is low.