Irinotecan as the key chemotherapeutic agent in second-line treatment of metastatic gastric cancer after failure of first-line S-1 or S-1/CDDP therapy.

Background: S-1, an oral fluoropyrimidine, is one of the standard chemotherapeutic agents for the treatment of metastatic gastric cancer(MGC). However, the most effective second-line regimen after failure of treatment with first-line agents such as S-1 is yet to be determined. The aim of this study was to investigate the various second-line chemotherapy regimens in MGC patients.
Methods: We retrospectively studied patients with MGC who received second-line treatment after failure of the first-line S-1 or S-1/cisplatin treatment. The overall survival times with each second-line regimen were determined using the Kaplan-Meier method, and the effect on overall survival was analyzed using Cox regression analysis.
Results: The median survival time for all patients was 14. 2 months(95% confidence interval(CI): 12. 88-15. 43 months)with a 1-year survival rate of 60. 4%. Kaplan-Meier analysis revealed that the second-line regimens containing irinotecan significantly improved the median survival time as compared to regimens without irinotecan(median survival time: 16. 5 and 13. 8 months, respectively). Cox regression analysis showed that irinotecan-containing regimens were associated with improved overall survival(hazard ratio: 0. 165; 95% CI: 0. 041-0. 665).
Conclusion: The use of irinotecan-containing regimens as second-line chemotherapy after failure of first-line S-1 therapy may be beneficial for MGC patients.