Clinical efficacy and prognostic factors of intensity-modulated radiotherapy combined with chemotherapy for limited-stage small cell lung cancer

Abstract

Objective To investigate the clinical efficacy and prognosis of intensity-modulated radiotherapy (IMRT) combined with chemotherapy for limited-stage small cell lung cancer (LS-SCLC). Methods A retrospective analysis was performed on the clinical data of 484 LS-SCLC patients treated with chemoradiotherapy in our center from 2006 to 2014. The patients with partial or complete response to IMRT received prophylactic cranial irradiation (PCI). The Kaplan-Meier method was used to calculate survival rates, and the log-rank test and Cox regression were used for univariate and multivariate analyses, respectively. Results In all the patients, the follow-up rate was 93%; the median overall survival (OS) time was 23.8 months; the 2-, 3-, and 5-year OS rates were 48.7%, 39.8%, and 28.6%, respectively; the median progression-free survival (PFS) time was 14.1 months; the 2-, 3-, and 5-year PFS rates were 34.4%, 30.5%, and 28.3%, respectively. The incidence rates of grade ≥3 bone marrow suppression, grade ≥2 radiation esophagitis, and grade ≥2 radiation pneumonitis were 26.9%, 24.8%, and 18.4%, respectively, in SCLC patients after IMRT. The objective response rate was 84.5%. The univariate analysis showed that age, smoking history, TNM stage, PCI, and the number of chemotherapy cycles before radiotherapy were prognostic factors for OS (P=0.006, 0.001, 0.047, 0.000, and 0.046). The multivariate analysis showed that smoking history and PCI were independent prognostic factors (P=0.001 and 0.000). Conclusions IMRT combined with chemotherapy achieves satisfactory clinical outcomes in the treatment of LS-SCLC. Smoking history and PCI are independent prognostic factors for OS of LS-SCLC patients. Key words: Carcinoma, small cell lung/intensity modulated radiotherapy; Combined modality therapy; Prognosis