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

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.

KEYWORDS:

• Colorectal cancer
• chemotherapy
• elderly
• survival
• recurrence

Abbreviations

OS: overall survival

DFS: disease-free survival

Authors’ contributions

J Chen, C Zhang conceived and designed the study; J Chen, C ZZhang,and Y Wu were involved in literature search and data collection; J Chen, C ZZhang,and Y Wu analyzed the data; Y Wu wrote the paper and reviewed and edited the manuscript. All authors read and approved the final manuscript.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Additional information

Funding

The second chest radiotherapy ward of Shanxi Cancer Hospital (No. 2019139).