Palliative chemotherapy for advanced colorectal cancer: systematic review and meta-analysis

Objectives To determine the benefits and harms of palliative chemotherapy in patients with locally advanced or metastatic colorectal cancer and to compare the outcomes for elderly and younger patients. Design Meta-analysis of individual patient data and published summary statistics from trials for which individual patient data could not be obtained from the investigators. Studies All randomised controlled trials comparing palliative chemotherapy with supportive care in patients with advanced colorectal cancer that were identified by computerised and hand searches of the literature, scanning references, and contacting investigators. Main outcome measures Survival, disease progression, quality of life, and toxicity. Results 13 randomised controlled trials including a total of 1365 patients met the inclusion criteria. Meta-analysis of seven trials that provided individual patient data (866 patients) showed that palliative chemotherapy was associated with a 35% reduction in the risk of death (95% confidence interval 24% to 44%). This translates into an absolute improvement in survival of 16% at both six and 12 months and an improvement in median survival of 3.7 months. No age related differences were found in the effectiveness of chemotherapy, but elderly patients were under represented in trials. The overall quality of evidence relating to treatment toxicity symptom control, and quality of life was poor. Conclusions Chemotherapy is effective in prolonging time to disease progression and survival in patients with advanced colorectal cancer. The survival benefit may be underestimated in this analysis as some patients in the control arms received chemotherapy.