Bo Li¹, Zhengming Wang², Suozhu Sun³, Bing Liu⁴, Zhenzhen Li⁴, Kaijin Wang⁴, Xifan Wang⁴, Wei Xu⁴, Jiaomin Chen⁴, Huoming Chen⁴

¹Department of Oncology, The SecondArtillery General Hospital PLA, ²Department of Imaging,The Second Artillery General Hospital PLA, ³Department of Pathology,The Second Artillery General Hospital PLA, ⁴Department of MedicalOncology of PLA Cancer Center, The Second Artillery General Hospital PLA

Objective:To explore the risk factors of brainmetastasis (BM) and the role of treatment in patients with small cell lungcancer. Method: Clinical data of 263 prophylactic cranial irradiation(PCI) naïve patients of small cell lung cancer who were diagnosed betweenJanuary 2003 and March 2014 were analyzed retrospectively. Factors includinggender (male vs female), age (<60ys vs ≥60ys), stage, smoking status (nevervscurrent) were analyzed. Furthermore, the influence of treatment mortalities onbrain-metastasis-free survival (BMFS) and post-brain-metastasis survival (PBMS)were also studied. Result: Patients with stage II-IV at diagnosis hadsignificantly higher incidence of BM compared with those with stage I (P=0.01).Those with T1/2 (P=0.05) and never-smoking history (P=0.06) hadshorter BMFS. In patients with stage II disease at diagnosis, there was atendency that those received chemotherapy and radiotherapy had longer BMFScompared with those received chemotherapy only (21months vs 12months, P=0.06).While the difference between patients received concomitant and sequential chemoradiotherapywas comparable (P=0.63). Furthermore, in stage II patients who receivedchemotherapy only, those obtained complete remission and partialremission hadsignificantly longer BMFS (12 months vs 3 months, P<0.001). When BMoccurred, radiation to the brain could significantly improve PBMS (P<0.001).Although those received both whole brain radiation therapy (WBRT) andstereotactic radiosurgery (SRS) had longer PBMS than those received either WBRTor SRS, the difference did not reach the significant level (P=0.1).Post-BM chemotherapy could prolong the PBMS (P=0.05). However, inpatients received WBRT and/or SRS, additional chemotherapy did not furtherimproved the PBMS (P=0.2). Conclusion: Patients with stage II-IVdisease had significantly higher incidence of BM. Chmoradiotherapy couldprolongthe BMFS in patients with stage II disease. Radiotherapy to the brain couldsignificantly improve PBMS, however, additional chemotherapy failed to furtherimprove PBMS.

Key Words: small cell lung cancer  brain metastasis  surgery