Does adjuvant chemotherapy improve outcomes in elderly patients with colorectal cancer? A systematic review and meta-analysis of real-world studies

Abstract

ABSTRACT Background Elderly patients are frequently excluded from randomized trials. It is unclear if adjuvant chemotherapy improves outcomes of colorectal cancer in such patients. The current study aimed to review evidence on the impact of adjuvant chemotherapy on overall survival (OS) and disease-free survival (DFS) in elderly patients with stage II/III colorectal cancer by pooling data from real-world studies. Methods PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched for observational studies reporting adjusted data on OS and DFS in elderly (≥70 years) colorectal cancer patients based on receipt of adjuvant chemotherapy. Results Thirteen studies included. The meta-analysis demonstrated statistically significant improved OS in elderly patients receiving adjuvant chemotherapy (p < 0.00001). Results were similar for sub-group analysis based on cancer stage and definition of elderly. Improvement in OS was noted in only Western population studies with no difference in Asian patients. The meta-analysis also revealed no statistically significant difference in DFS in elderly patients receiving adjuvant chemotherapy vs surgery alone (p = 0.14). Conclusion Real-world evidence indicates that adjuvant chemotherapy significantly improved OS but not DFS in elderly colorectal cancer patients. Scarce evidence suggests a limited role of adjuvant chemotherapy in Asian patients which needs confirmation by further studies.