Multivariate Analysis The Survival And The Efficacy Of Phylactic Cranial Irradiation In Small Cell Lung Cancer

Objective:The aim of this study is to clear the prognostic factors related to the overall survival、progression free survival、local/region recurrence free survival and distant metastasis free survival of small cell lung cancer and to find the individual predictive parameters of prognosis and decide the best treatment modolity of limited-stage small cell lung cancer.Methods:A retrospective study was performed on 241 SCLC patients treated in our hospital receiving chemotherapy±radiotherapy from January2015 to December 2018.Recorded the patients’general clinical data,laboratory parameters and treatment plan.SPSS 23.0 software was used for statistical analysis.The Kaplan-Meier method was used for survival analysis,and log-rank test and Cox regression were used for unicariate and multivariate analysis of prognostic factors,especially in 174 limited-stage small cell lung in detail.Results:The follow-up time was cut off at January 10,2021 with 6patients lost and the follow-up rate was 97.5%.85 patients survived and 156patients died,the median survival time was 21 months（18.1-23.9months）.Limited/extensive stage and short-term outcome were independent prognostic factors for OS,T stage,TNM clinical stage,treatment therapy,short-term outcome and PCI were independent prognostic factors for PFS.As for limited-stage small cell lung cancer,the median OS was 26 months（19.6-32.4 months）,and the 6-month,1-year,2-year survival rates were 99.4%,84.5%and 55.2%,respectively.The median PFS was 15 months（12.3-17.7months）,and the survival rates were 90.8%,53.3%and 33.4%,respectively.A total of 64 patients（36.8%）presented with local/regional recurrence,with survival rates of 97.1%,81.2%and 60.5%.And 113 patients（64.9%）presented with distant metastasis,the distant metastases-free rates were 93.1%,59.0%and 39.0%respectively.The univariate analysis showed that sex,NSE pre-treatment,short-term outcome and PCI were OS related.Pleural effusion,T、N stage,TNM clinical stage,Pro-GRP,NSE,the number of first-line chemotherapy,short-term outcome and PCI were the prognostic factors of PFS.Pleural effusion,T stage,NSE pre-treatment,time of radiotherapy,short-term outcome and PCI were the prognostic factors of LRFS.The factors affecting DMFS included pleural effusion,T、N stage,TNM clinical stage,Pro-GRP,NSE and NSE degree of decline after chemotherapy,short-term outcome,PCI and local control.The independent prognostic factors of OS were sex,short-term outcome,number of first-line chemotherapy and time of radiotherapy.T stage,short-term outcome and PCI were independent prognostic factors of PFS and DMFS.Short-term outcome and PCI were independent prognostic factors of LRFS.PCI can reduce the incidence of brain metastasis,and dose of 25Gy/10F can further reduce the incidence of brain metastasis and prolong PFS than higher dose,but had no effect on OS.The time of PCI had no significant effect on prognosis.No OS benefit from PCI was found in male patients,age≥60 years,T₃+T₄,N₂,N₃,stage III,and patients with anemia pre-treatment.Conclusions:1.For small cell lung cancer,limited/extensive stage and short-term outcome were independent prognostic factors for OS,T stage,TNM clinical stage,treatment therapy,short-term outcome and PCI were independent prognostic factors for PFS.2.For limited-stage small cell lung cancer,the independent prognostic factors of OS were sex,short-term outcome,number of first-line chemotherapy and time of radiotherapy.T stage,short-term outcome and PCI were independent prognostic factors of PFS and DMFS.Short-term outcome and PCI were independent prognostic factors of LRFS.3.Standard protocol of PCI with 25Gy/10F should be performed as soon as possible after effective therapy in limited-stage small cell lung cancer.Patients over 60 years old,with advanced stage and anemia pre-treatment should be carefully selected.