ABSTRACT
Objective:To compare the survival outcomes in patients of small cell lung cancer (SCLC) with brain-single metastasis and brain with organs-multiple metastasis.Methods:Using the US surveillance, epidemiology and final results database, 5 520 SCLC patients with complete clinical information from 2004 to 2015 were selected. SCLC patients were adjusted, stratified or matched according to the metastasis site after the stratification or matching of the propensity scores, and the lung cancer-specific survival (CSS) rate and overall survival (OS) rate were compared between brain-single metastasis group and brain with organs-multiple metastasis group. In addition, the effects of chemotherapy and radiotherapy in CSS between brain-single metastasis group and brain with organs-multiple metastasis group were compared.Results:Of the 5 520 SCLC patients, 2 658 cases was in the brain-single metastasis group, and 2 862 cases was in brain with organs-multiple metastasis group. After the stratification or matching of the propensity scores, the median survival time in brain-single metastasis group was significantly longer than that in brain with organs-multiple metastasis group (6 months vs. 4 months), and there was statistical difference ( P<0.05). The fatality rate in brain-single metastasis group was significantly lower than that in brain with organs-multiple metastasis group (80.66% vs. 85.96%), and there was statistical difference ( P<0.01). Kaplan-Meier survival curve analysis result showed that the OS rate and CSS rate in brain-single metastasis group were significantly higher than those in brain with organs-multiple metastasis group (14.72% vs. 9.50% and 19.34% vs. 14.04%), and there were statistical differences ( P<0.05). Cox analysis result showed that age, race, T stage, gender, N stage, radiotherapy, chemotherapy, tumor diameter, marriage and metastasis were the influencing factors of CSS rate in SCLC patients with brain metastasis ( P<0.01 or <0.05). Multivariate Logistic regression analysis result showed that radiotherapy and chemotherapy can significantly improve the CSS rate ( HR = 0.668 and 0.671, 95% CI 0.570 to 0.783 and 0.573 to 0.786, P < 0.01). Conclusions:The survival rate in SCLC patients with brain-single metastasis is higher than that of SCLC patients with brain with organs-multiple metastasis; chemotherapy and radiotherapy can improve the survival rate in SCLC patients with brain metastasis.