To study the efficacy of different dosages of oxaliplatin plus S-1 on thrombocytopenia for the treatment of advanced gastric cancer.

Between August 2014 and May 2016, a total of 60 advanced gastric cancer patients at the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College were recruited to the study, and divided into two groups. Arm A received oxaliplatin at a dose of 100 mg/m² and arm B receiving oxaliplatin at a dose of 130 mg/m², started with SOX therapy. Adverse events were graded according to the National Cancer Institute-Common Toxicity Criteria version 3.0. This study used SPSS 19.0 software to undertake statistical analysis. Comparison of groups was statistically analyzed with X² test. Two-sided P<0.05 was used to indicate a statistically significant difference.

In total, the most common grade 3/4 toxicities were anemia, leukopenia, neutropenia, thrombocytopenia, nausea and vomiting in the treatment of SOX therapy for advanced gastric cancer. The incidence ofgrade 3/4 thrombocytopenia in arm A was 6.67%, which was significantly lower in arm B with 30.0%. Grade 3/4 thrombocytopenia was significantly associated with the dose of oxaliplatin [OR=3.846, 95%CI (1.091~13.56), P=0.0286) ].

The dose of oxaliplatin was one of the factors which affected affects grade 3/4 thrombocytopenia in the treatment of SOX therapy for advanced gastric cancer patients.