Post-operative adjuvant chemotherapy is not indicated for stage IB/IIA gastric cancer. However, approximately 10-30% of these patients experience recurrence and metastasis. In this study, we investigated the risk of recurrence after treatment of stage IB/IIA gastric cancer patients carrying the TP53 codon 72 polymorphism and attempted to identify a subpopulation that should receive post-operative adjuvant chemotherapy.
Among 658 gastric cancer patients who received gastrectomy with curative-intent, 130 stage IB and 73 stage IIA patients were enrolled in the present study. Overall survival rate (OS) and relapse-free survival rate (RFS) were analyzed based on the status of TP53 codon 72 polymorphism Arg/Arg, Arg/Pro, and Pro/Pro. The hazard ratio for each subgroup was compared by TP53 codon 72 polymorphism. All interaction p values were calculated using the likelihood test.
Of the 189 patients for whom polymorphism analysis results were available, the 5- and 10-year OS was 84.9% and 65.1%, respectively. The 5- and 10-year RFS was 81.8% and 65.4%, respectively. When the study cohort was divided into two groups according to polymorphism status (i.e., "Arg/Arg and Arg/Pro" vs. Pro/Pro), both the OS (hazard ratio [HR], 2.799; 95% confidence interval [CI], 1.071-7.315, p = 0.036) and RFS (HR, 2.639; 95% CI, 1.025-6.794, p = 0.044) of the Pro/Pro group were significantly lower than those for the Arg/Arg and Arg/Pro groups across the entire observation period.
Among stage IB/IIA gastric cancer patients that underwent gastrectomy with curative-intent, post-operative adjuvant chemotherapy may be considered for patients carrying the TP53 codon 72 Pro/Pro polymorphism.
NCT01905969.
Christopher Brooks of Bioscience Editing Solutions.
The authors.
Ministry of Education, Culture, Sports, Science and Technology, Japan.
Y. Ohmori: Full / Part-time employment: Astellas Pharma Inc.