Twenty-seven RCTs (n=4,198) were included in the review.
Chemotherapy versus best supportive care (3 RCTs, n=184): overall survival was significantly longer in the chemotherapy groups (all used combination therapy) than in the best supportive care groups (HR 0.39, 95% CI: 0.28, 0.52).
Combination versus single-agent chemotherapy (11 RCTs, n=1,472): overall survival was significantly longer in the combination groups (most used fluorouracil plus an anthracycline) than in the single-agent (mainly fluorouracil) chemotherapy groups (HR 0.83, 95% CI: 0.74, 0.93).
Fluorouracil/cisplatin/anthracycline versus fluorouracil/cisplatin combinations (3 RCTs, n=501): overall survival was significantly longer in the groups treated with three-agent combination chemotherapy than in those treated with the two-agent combination (HR 0.77, 95% CI: 0.62, 0.91).
Fluorouracil/cisplatin/anthracycline versus fluorouracil/anthracycline combinations (7 RCTs, n=1,147): overall survival was significantly longer in the groups treated with three-agent combination chemotherapy than in those treated with the two-agent combination (HR 0.83, 95% CI: 0.76, 0.91).
Irinotecan-containing chemotherapy combinations versus non-irinotecan-containing combinations (3 RCTs, n=536): there was no significant difference between the groups in length of overall survival: the HR was 0.88 (95% CI: 0.73, 1.06) in favour of irinotecan-containing combinations.