Which is more recommendable as the second line chemotherapy to S-1 for advanced gastric cancer; combination of CPT-11 plus CDDP or weekly paclitaxel?

Abstract

4136 Background: Since S-1 has the highest response rate as a single-agent for advanced gastric cancer (AGC) is usually used as the first line chemotherapy in Japan. Imamura et al. reported that combination of CPT-11 plus CDDP treatment for AGC showed a good response rate (52%) and its adverse reactions were mild (ASCO 2002; 622 abstr.). On the other hand Arai et al. reported that Paclitaxel was active in AGC with a good safety profile, feasibility and activity as salvage treatment (ASCO 2003; 1040 abstr.). The aim of this study is to evaluate which is recommendable as a subsequent second line chemotherapy to S-1;depends on document reviewcombination of CPT-11 plus CDDP (group A) ordepends on document reviewPaclitaxel (group B). Methods: The eligibility criteria included microscopically proven advanced and/or recurrent gastric cancer with measurable metastatic lesions; adequate organ functions; oral intake is possible; ECOG PS of 0, 1 or 2; an age of <= 75; no prior chemotherapy; and provision of written informed consent. S-1 was administered orally 40mg/m2 twice a day for 28 consecutive days followed by a 14-day rest period. When tumor progression is observed, the second line treatment followed after 2 weeks rest. The treatment regimen consisting of CPT-11 (60mg/m2) on days 1 and 15 and CDDP (10mg/m2) on days 1, 2, 3, 15, 16, and 17 (group A; 14 patients) or Paclitaxel (70mg/m2) by on days 1, 8, 15 (group B; 11 patients) was repeated every 4 weeks. Results: The overall response rate (RR) of S-1 as the first line chemotherapy was 36% (2 CRs, 7 PRs, 10 SDs and 6 PDs). Neither grade 4 hematological toxicities nor grade 3 or 4 febrile neutropenia occurred. RRs of second line therapy in group A and B were 36% (5 PRs, 6 SDs and 3 PDs) and 36% (1 CR, 3 PRs, 4 SDs and 3 PDs), respectively (P=0.6784). There were no treatment-related deaths. After median follow up periods from the first line chemotherapy of 875 (488–1171) and 319 (163–1027) days, 1-year survival rats were 30% (MST; 355 days) and 89% in group A and B, respectively (P=0.026). Conclusion: Both regimens showed similar RR and Paclitaxel as the second line showed a better one-year survival rate than a combination of CPT-11 plus CDDP. No significant financial relationships to disclose.