Background: The impact of the duration of chemotherapy on the overall survival of patients with metastatic colorectal cancer (mCRC) is controversial and studies have failed to define a clear standard.
Methods: We searched medical literature databases and oncology conferences proceedings for randomized controlled trials (RCT) that compared the overall survival of mCRC patients who received continuous first-line chemotherapy until disease progression versus those who were offered complete treatment stop after a fixed number of cycles. Studies including targeted agents were also included. A meta-analysis of reported hazard ratios (HRs) for survival was performed.
Results: We retrieved 240 trials, of which six were eligible and five were included in the pooled analysis of overall survival (N = 3061). The overall survival between continuously delivered chemotherapy and complete stop was not statistically different (HR = 0.93, 95% CI 0.85-1.02; p = 0.12; I² = 5%). The results are similar when we analyzed separately the trials performing randomization before versus after induction therapy. The median chemotherapy free interval in the complete stop group was 3.9 months (3.6-4.3 months). Chemotherapy administered until progression was associated with more adverse effects and impaired quality of life.
Conclusion: Compared with first-line continuous chemotherapy administered until disease progression, complete treatment stop did not have a detrimental impact on the overall survival of patients with mCRC. Identification of predictive biomarkers could help clinicians to select the patients who would benefit from continuous cancer-directed therapies.