A Retrospective Study Comparing S-1 Plus Oxaliplatin With S-1 Plus Docetaxel

Objective:The aim of this study was to evaluate the efficacy and safety of S-1 plus oxaliplatin(SOX) comparing with S-1 plus docetaxel(DS) in the first-line treatment of patients with advanced or recurrent gastric cancer in a retrospective way, as well as try to analysis prognostic factors.Patients and methods:84 patients with AGC who at least received 2 cycles of chemotherapy in the department of oncology between January 1, 2008 and October 31, 2015 were retrospectively analyzed in the the First Affiliated Hospital Of Nanchang University,with 41 patients in the SOX group and 43 patients in the DS group. Patients received docetaxel infusion 75mg/m2 in the DS group or oxaliplatin infusion 130 mg/m2 in the SOX group at day 1 of each 3-week cycle, while S-1 was administered orally 80mg/m2/day,twice daily for 2 weeks, followed by a 7-day rest; both schedules were repeated every 3 weeks. The objective response rate(ORR), disease control rate(DCR),progression- free survival(PFS), overall survival(OS) and adverse events were evaluated using SPSS 18.0 software. At the same time, the survival curves were depicted by Kaplan-Meier method, and the COX proportional hazards model was applied for multivariate analysis of prognostic.Results:Among 84 patients enrolled,41 patients were in the SOX group and 43 patients in the DS group. The median PFS was 4.8 months in the SOX group and 4.9months in the DS group. The median OS was 11.0 in the SOX group and 11.1 months in the DS group. The overall response rates for SOX and DS were 53.66%and58.14%,respectively, and the disease control rates were 80.48% and78.72% for SOX and DS, respectively. All the results were with no significant difference(P>0.05).Comparisons of safety between the SOX regimen and DS regime indicate that a lower incidence of toxicity in aspects of thrombocytopenia(34.1% vesus 58.1%)and hand–foot syndrome(19.5% vesus 41.8%) with SOX regimen than DS regime. Onthe other hand, the incidence of hepatic dysfunction was higher with SOX regimen(51.2% versus 25.6%).Sensory neuropathy is a characteristic toxicity of oxaliplatin,and 85.3% of the patients receiving SOX regimen had neuropathy, but only 2patients(4.8%) had severe(grade 3/4) neuropathy. The most common ? grade 3adverse events(SOX versus DS) were neutropenia(19.5% versus 16.2%),thrombocytopenia(9.7versus 18.6%), anemia(12.1% versus 13.9%),hepatic dysfunction(2.4% versus 0%), anorexia(4.8% versus 4.6%), and sensory neuropathy(4.8% versus 0%),with no significant difference(P>0.05). Multivariate analysis showed that the prognostic factors of OS included ECOG performance status,the baseline CEA level and the baseline CA125 level.Conclusion:Both combination regimes, SOX and DS, were active and well tolerated in advanced gastric cancer patients.There was a higher incidence of hepatic dysfunction and sensory neuropathy with SOX regimen, while a higher incidence of thrombocytopenia and hand–foot syndrome with DS regimen. ECOG performance status, the baseline CEA level,the baseline CA125 level were independent prognostic factors for OS.