| ObjectiveTo analyze the prognostic factors of patients with limited stage small cell lung cancer and construct an effective Nomogram model to predict the survival rate of these patients.MethodsA total of 3788 patients who were diagnosed with limited-stage small cell lung cancer from 2004 to 2015 were selected from Surveillance,Epidemiology,and End Results(SEER)database.The collected patient information includes demographic information(age,sex,race),oncology information(primary location,differentiation degree,tumor tissue size,lymph node status,distant metastasis),treatment methods(surgery,radiotherapy,chemotherapy),survival time(months),survival status(live or death).According to the oncology information,the 8th edition of TNM staging system issued by American Joint Commission on Cancer(AJCC)was used for staging adjustment.Set the seed number by "Caret" program in R package,and randomly divide all patients into training queue and verification queue according to the ratio of7:3.In this study,"Survival time" is taken as the survival time and "Death" as the research end point.Statistical analysis was performed with STATA(version 16.0),R(version 4.0.3)and SPSS(version 26.0).Kaplan-Meier method and Log-rank test were used for univariate survival analysis.Multivariate COX regression analysis was used to screen independent prognostic factors.Independent prognostic factors were used to construct a Nomogram prediction model for survival of these patients.The receiver operating characteristic curve(ROC)was plotted and the area under the curve(AUC)was used to evaluate the discrimination of the model,the calibration chart was used to test the consistency of the model,and the clinical decision curve(DCA)was used to analyze the practicality of the model.The closer the AUC is to 1,the better the discrimination,the closer the calibration curve is to 45 diagonal,the better the fitting degree,and the greater the threshold probability and net benefit of DCA curve,the stronger the practicability.Results(1)Univariate Kaplan-Meier analysis showed that age,sex,differentiation degree,TNM stage,surgical treatment,radiotherapy and chemotherapy were related to the survival time of LS-SCLC patients,and the difference was statistically significant(P< 0.05).Race and lesion site were not related to the survival time of LS-SCLC patients(P > 0.05);(2)Multivariate COX regression analysis showed that age,sex,TNM stage,surgical treatment,radiotherapy and chemotherapy were independent prognostic factors for the survival of LS-SCLC patients(P < 0.05);(3)The AUC of 1-year,2-year and 5-year Nomogram prediction model were0.738、0.715、0.733 respectively;(4)The calibration chart of 1-year,2-year and 5-year survival rate of LS-SCLC patients in training cohort and verification cohort showed that the predicted survival rate was in good agreement with the actual survival rate;(5)In the training cohort and verification cohort,the threshold probability and net benefit of the Nomogram prediction model were better than those of the 8th edition TNM stage.Conclusions(1)Age,sex,TNM stage,surgery,radiotherapy and chemotherapy are independent prognostic factors affecting the survival of patients with LS-SCLC.(2)The Nomogram prediction model can be used to predict the survival of patients with LS-SCLC,which is helpful for better individualized treatment and prognosis evaluation. |
