A Cochrane review ¹ included 6 studies with a total of 491 subjects. The overall hazard ratio for survival was 0.75 (95% CI 0.60 to 0.96, p=0.019), suggesting a 25% relative reduction in the risk of death for chemotherapy compared to that on control. The impact of trials that stopped early, of patients not receiving allocated treatments or not receiving salvage chemotherapy is unclear. The power of the meta-analysis is clearly limited.

Comment: The quality of evidence is downgraded by imprecise results (limited study size for each comparison).