S-1-based regimens and the risk of leucopenic complications; a Meta-analysis with comparison to other fluoropyrimidines and non fluoropyrimidines.

BACKGROUND: We performed a meta-analysis oriented at the risk of leucopenic complications associated with S-1-based regimens.

PATIENTS AND METHODS: The studies that were granted eligibility for inclusion include randomized phase II and III trials of patients with solid tumors on S-1; that entailed details of events of febrile neutropenia, all-grade and high-grade neutropenia and leucopenia.

RESULTS: After rejecting ineligible studies, a total of 28 clinical trials were elected eligible for further quantitative analysis. The RR of febrile neutropenia, all-grade and high-grade neutropenia for S-1 vs.non fluoropyrimidine controls was 0.27 [95% CI 0.16, 0.46; P < 0.0001] 0.69 [95% CI 0.58, 0.81; P < 0.00001] and 0.47 [95% CI 0.32, 0.70; P = 0.0002], correspondingly; while The RR of all-grade and high-grade leucopenia for S-1 vs.non fluoropyrimidine controls was 0.60 [95% CI 0.46, 0.79; P = 0.0002] and 0.34 [95% CI 0.14, 0.79; P = 0.01], respectively.

CONCLUSIONS: The risk of febrile neutropenia, all-grade and high-grade neutropenia and leucopenia is less in S-1-based therapy than in non fluoropyrimidine regimens; yet comparable to the risk associated with infusional 5FU or capecitabine-based regimens.