A Retrospective Study On The Effect Of Prophylactic Brain Irradiation On Survival In Limited-Stage Small Cell Lung Cancer

Objective:The purpose of the study was to explore the effect of prophylactic brain irradiation(PCI)on the survival of patients with local-disease small cell lung cancer(LD-SCLC),to find out the best beneficial group or non-beneficial group and to provide a theoretical basis for the adjustment of treatment plan for LD-SCLC.Methods:We collected patients in Shandong Cancer Hospital Affiliated to Shandong University from 2012 to 2014 through medical record query system,who were diagnose as LD-SCLC by pathological or cytological technology and imaging examination.Only those that achieved complete response(CR)or partial response(PR),after the first stage therapy such as chemotherapy,radiotherapy or surgery.Basic information,treatment methods and survival were collected.According to whether PCI was performed,patients were divided into PCI group and observation group.Overall survival(OS),intracranial progression-free survival(IPFS)and progression-free survival(PFS)were estimated by Kaplan-Meier method,Log-rank non-parametric test and COX regression.Results:349 LD-SCLC patients were included in the analysis,with 129 patients in the PCI group and 220 patients in the observation group.(1)The whole median OS was 52.1 months,76.3 months in the PCI group and 50.3 months in the observation group,respectively,P=0.023.PCI and CR are important prognosis factors for OS.In stratified analysis,only in men(49.8 vs.39.7,P = 0.027),PR(60.2 vs 36.0,P = 0.004),and mediastinal lymph node metastasis(76.3 vs 36.0,P = 0.006)were found that patients with PCI were benefited,while women,PR,without lymph node metastasis,only the ipsilateral lung lymph node metastasis or supraclavicular lymph node metastasis patients did not found OS benefits.It had nothing to do with age,smoking history,the T stage.(2)PCI significantly extended IPFS.But in stratified analysis of T and N stages,no benefit was found in patients with T3,NO and ipsilateral supraclavicular lymph node metastasis(P>0.05).(3)The overall median PFS was 14.7 months,and the median PFS in the PCI group were 25.1 months and in the observation group 11.3 months,respectively,P=0.0001.In the stratified analysis of gender,effect evaluation of initial treatment,smoking history and age,all showed significant PFS benefits(P=0.01).In stratified analysis of T and N stage,no benefit was found in patients with T3,NO and ipsilateral supraclavicular lymph node metastasis(P>0.05).Conclusion:PCI is recommended for patients with non-NO stage LD-SCLC who have achieved remission after initial treatment,especially for men,PR or mediastinal lymph node metastasis.Women without lymph node metastasis,CR should be considered for close follow-up observation instead of PCI.