Chemoradiotherapy for locally advanced inoperable gastric cancer: a prospective analysis of survival

Background. The proportion of patients with initially locally advanced inoperable gastric cancer (LAIGC) is up to 30%. Currently, chemotherapy (CT) is the only and purely palliative treatment for patients with LAIGC. Radiation therapy (RT) alone or in combination with the CT of 5-fluorouracil, for inoperablegastric cancer is usually administered for relieving the symptoms of disease. Studies have shown the advantage of chemoradiotherapy (CRT) compared to RT, CT, but the study on the use of platinum-based combination CT in combination with RT in the treatment of patients with LAIGC not previously published. Purpose. to compare the effectiveness of CRT and CT by progression-free survival in patients with LAIGC within an open, prospective, randomized study. Methods and Materials. Randomization was carried out by the ratio 1:1. Radiation therapy was administered to a total dose of 50-68 Gy on defined target, with the first 40-44 Gy delivered within an area, encompassing lymphatic stations up to the D2+ level. Chemotherapy scheme included cisplatin 100 mg/m 2 i.v. on the D, 1, 5-fluorouracil 1000 mg/m 2 by 24-hour intravenous infusion on D1-5, totally 4-6 courses. Primary end point for comparison was progression-free survival, while secondary endpoints were response rate, toxicity of treatment, and overall survival. Distributions were estimated using the chi-square test. Survival was graphically presented with Kaplan-Meier curves, the differences in the groups were evaluated by log-rank method. Associations between survival and contributing factors were studied using Cox regression. Results. Sixty four patients with LAIGC were totally enrolled to CRT (n=32) and CT (n=32) arms. Median follow-up of all patients was 15.1 months, 28 (43.8%) patients have died. Median progressionfree survival in patients, receiving CRT, was 8.8 (95% CI: 6,5-11,1) months, CT 6.5 (95% CI: 3,9-9,2) months, respectively (χ2 = 8,988, p = 0.003). The results of the multivariate analysis showed that radiation therapy was associated with reduced progression risk, RR=0,48, (95% CI: 0,23-0,96). The median overall survival of patients in the CRT and CT groups was 15.1 (95% CI: 13,1-17,0) months and 11.1 (95% CI: 8,9-13,3) months, respectively (χ2 = 0,878, p = 0.349). Objective response rate in the CRT group was 18.8%, in the CT group 9.4%. Statistically significant differences in toxicity in the treatment groups were not observed. Conclusion. Addition RT to CT in LAIGC does not lead to significant increase in toxicity compared with only CT. The progression-free survival rate was found to be higher in patients with LAIGC who received CRT compared to patients receiving CT only.