A systematic review including 4 studies with a total of 875 subjects was abstracted in DARE. Individual patient data was analyzed. Chemotherapy significantly reduced the risk of death compared with no chemotherapy (HR 0.75, 95% CI: 0.64 to 0.90, P=0.001). After removing one RCT with an unusually high proportion of patients with positive resection margins, significant heterogeneity was no longer present (P=0.29) and the reduction in risk of death with chemotherapy was still statistically significant (HR 0.65, 95% CI: 0.54 to 0.80, P<0.001). Median survival was 19 months with chemotherapy and 13.5 months without. The 2- and 5- year survival rates were 38% and 19%, respectively, with chemotherapy and 28% and 12% without. There was no difference in the risk of death with chemoradiation compared with no chemoradiation (HR 1.09, 95% CI: 0.89 to 1.32, P=0.43). Median survival was 15.8 months with chemoradiation and 15.2 months without.
Comment: The quality of evidence is downgraded by poor reporting of review methodology.