Clinical Efficacy of Gemcitabine plus S-1 on Refractory Nasopharyngeal Carcinoma Patients and Their Influence on Immune Function

Objective To investigate the efficacy of gemcitabine plus S-1 on refractory nasopharyngeal carcinoma patients, and to detect the changes of T lymphocyte subsets in the peripheral blood before and after chemotherapy.

Methods Forty-two refractory nasopharyngeal carcinoma patients received gemcitabine (1.0 g/m² on day 1 and day 8) plus oral S-1 chemotherapy (40mg/m² twice daily, d1-14). Each cycle was repeated every 21 days, two cycles at least for each patient. The peripheral blood samples were collected before and after chemotherapy respectively, then T lymphocyte subsets were analyzed by flow cytometry. Survival analysis included univariate model and multivariate Cox regression model.

Results Forty-two patients had completed chemotherapy and follow-up. There was one case of complete response, 21 cases of partial responses, 12 cases of stable disease, 8 cases of progressive disease, the overall response rate was 52.4%(22/42), and the disease control rate was 81.0%(34/42). Median time to progression was 6.8 months and median survival was 14.6 months. The common adverse effects were myelosuppression, gastrointestinal tract reaction, rash and fatigue; no death occurred in relation to the therapy. Compared with PD group, the percentages of CD3⁺, CD3⁺CD4⁺ and CD4⁺/CD8⁺ ratios were increased significantly in the response group after chemotherapy. Liver metastasis was an independent prognostic factor for overall survival.

Conclusion Gemcitabine plus S-1 are an effective therapy with tolerable toxicity profile for refractory NPC patients. Liver metastasis is an independent prognostic factor for overall survival. Effective chemotherapy influences T lymphocyte subsets obviously.