Association between the timing of brain metastases and the prognosis of small cell lung cancer

Objective To investigate the association between the timing of brain metastases and the prognosis of patients with small cell lung cancer (SCLC). Methods A retrospective analysis was performed in 131 patients with limited-stage SCLC firstly metastasized to the brain were admitted to our hospital from 2007 to 2015.According to the median bone metastasis-free survival (BMFS), all patients were divided into A group (BMFS≤10 months, n=61) and B group (BMFS>10 months, n=70). The survival rates were analyzed using the Kaplan-Meier method. Between-group comparison was performed by log-rank test. The Cox regression model was used for multivariate prognostic analysis. Results In all 131 patients, the median overall survival (OS) and 1-, 2-, and 3-year OS rates were 22.5 months, 87.3%, 44.7%, and 20.8%, respectively. The median OS after brain metastases and 1-and 2-year OS rates were 9.3 months, 39.3% and 14.8%, respectively. No statistical significance was observed in the median OS after brain metastases between the A and B groups (8.6 vs. 9.3 months, P=0.695). Moreover, the OS after brain metastases did not significantly differ in patients without PCI or those receiving different therapies after brain metastases between two groups (P=0.240-0.731). Conclusions The timing of SCLC with brain metastases is significantly correlated with the OS rather than the OS after brain metastases. Therefore, prevention of brain metastases may be an effective approach to prolong the OS of patients with SCLC. Key words: Carcinoma, small cell lung/radiotherapy; Neoplasm metastasis/brain; Timing of metastasis; Prognosis