Preoperative radiotherapy for gastric cancer: retrospective one-center long-term survival analysis and literature review

Introduction. Stomach cancer (SC) is the second leading cause of death from cancer in the world. Surgical removal is still cornerstone of treatment for SC. Whether preoperative radiotherapy (PR) may improve survival remains unclear. Objective: retrospective comparison of overall survival (OS) in patients with resectable SC after surgical and combined treatment in Arkhangelsk Clinical Cancer Center from 1998 to 2010. Materials and methods. The OS was retrospectively assessed in patients with resectable stage 2-3 and stage 4 M0, who received radical surgery or combination with preoperative radiotherapy. Initial distributions were compared using the chi-square method. The OS evaluated using Kaplan-Meier method with log-rank for intergroup comparisons. Cox regression was applied to adjust for initial factors and for assessment of factors influencing OS. Results. There were 75 patients in surgery alone group, while 145 patients were preoperatively irradiated. Of them, accelerated fractionation (2.5 Gy b.i.d. during 5 consecutive days to total 25 Gy, AF) and large fractions (15 or 22.5 Gy in 2 to 3 daily fractions, LF) were given to 89 and 56 patients, respectively. The median follow-up for all patients was 14 years. Median, 5-yr and 10-yr OS were 52 (95% 95% confidence interval (CI), 20-84), 70 (95% CI, 36-103) and 44 (95% CI, 21-70) months, χ2 = 2,96, p = 0,227; 45% (95% CI, 33- 57), 51% (95% CI, 41-61) and 41% (95% CI, 27-55); 39% (95% CI, 27-51), 42% (95% CI, 32-52) and 27% (95% CI, 15-39) in the surgical, AF and LF group, respectively. In multivariate analysis the RT was associated with non-significant decrease risk of death both in AF (HR 0.62, 95% CI 0.35 1.12), and LF (HR 0.89, 95% CI 0.52-1.53). The only prognostic factor, significantly affecting OS was the presence of regional lymph node metastatic lesions (HR 2.32, 95% CI, 1.62-3.32) and age of patients under 50 (HR 0.34, 95% CI 0.18-0.64) and 50-59 years (HR 0.50, 95% CI 0.28-0.91). Conclusion. The retrospective analysis shows that preoperative radiotherapy may improve survival of patients with resectable SC. Only involvement of regional lymph nodes and older age of patients were independent negative risk factors in this study.