Prognostic factors including age and sex interaction on the efficacy of CapeOX therapy after gastric cancer surgery

<p>While Gastrectomy is recommended worldwide as the standard treatment for gastric cancer (GC), there are regional differences in the choice of adjuvant chemotherapy. In East Asia, including Japan, capecitabine plus oxaliplatin (CapeOX) is the standard adjuvant chemotherapy. CapeOX was established in the CLASSIC trial conducted in Korea, China, and Taiwan, and demonstrated a 3-year disease-free survival (DFS) rate (HR 0.58, 95% CI 0. 47-0.72, p＜0.0001) and OS (HR 0.66, 95% CI 0.1-0.85, p0.0015). Although mean survival has improved, many patients experience serious adverse events. To optimize the medicine, prognostic factors affecting treatment need to be identified, including age and sex. Thus, we examined prognostic factors using a Cox proportional hazards model with stepwise variable selection based on individual patient information from the CLASSIC trial. The interaction of sex, age, and serum albumin for OS and tumor stage (T) and nodal status (N) for DFS were identified as significant. Other overall trends were consistent for OS and DFS. The HR for OS in female patients aged ≧55 years was 1.16 (95% CI 0.55-2.47) for albumin ＜4.0 g/dL and 2.39 (95% CI 1.15-4.94) for ≧4.0 g/dL, which seemed particularly the latter patients were found to be considerably less favorable for treatment. For patients with ≧T3 and ＜N2, the HR for DFS was 0.84 (95% CI 0.60-1.17), obscuring the benefit of treatment. Although these results are hypothetical due to the post hoc analysis, patient background should be fully considered when deciding on a treatment strategy for adjuvant therapy of GC.</p>