Prophylactic cranial irradiation could improve overall survival in patients with extensive small cell lung cancer : A retrospective study

To evaluate the effect of prophylactic cranial irradiation (PCI) on overall survival (OS) in patients with extensive small cell lung cancer (ESCLC). Between April 2005 and May 2014, 204 patients with ESCLC who had any response (according to RECIST 1.1) to initial chemotherapy were reviewed. All patients had undergone appropriate imaging tests to exclude brain metastases before initial chemotherapy. PCI was performed on 45 patients (22.1 %) and the remaining patients (77.9 %) received no such treatment (control group). Primary endpoint was OS. The incidence of brain metastases, brain metastases-free survival (BMFS), and adverse effects were also evaluated. Survival data of the 204 patients were analyzed statistically. PCI significantly prolonged median OS from 12.6 to 16.5 months as compared to the control group (hazard ratio, HR, 0.63; 95 % confidence interval, CI, 0.41 to 0.96; p = 0.033). PCI significantly lowered the risk of brain metastases (HR 0.48; 95 % CI 0.30 to 0.76; p = 0.001). The 1‑year incidence of brain metastases was 17.1 and 55.9 % in the PCI and control group, respectively. PCI significantly correlated with the increased median BMFS (p = 0.002). Additionally, multivariate analyses demonstrated that PCI was a favorable independent predictor of OS, BMFS, and the incidence of brain metastases. Acute and chronic adverse effects were generally low grade and well tolerated in patients receiving PCI. PCI after any response to initial chemotherapy significantly improved OS of ESCLC patients analyzed in this study.