Prognostic Analysis And Clinical Characteristics Of Dual Primary Lung Cancer:A Population Study Based On Surveillance,Epidemiology,and End Results(SEER) Database

Background:In recent years,lung cancer has been the leading cause of cancer mortality in the world.With the improvement of medical treatment,the survival time of patients with lung cancer is gradually prolonged,which leads to an increasing trend in the incidence and detection rate of dual primary lung cancer.According to the occurrence time of primary tumor,the dual primary lung cancer can be divided into two subtypes,one is simultaneous dual primary lung cancer,the other is metachronous dual primary lung cancer.At present,clinical and basic medical research on dual primary lung cancer is still insufficient,so that the clinical decision-making,clinicopathologic features,prognostic time and quality of life are not clear.Although the TNM system is widely used to assess the prognosis of patients with cancer,this criterion is more applicable to single primary cancers.Because of the different clinical and pathological characteristics between dual primary lung cancer and single primary lung cancer,there are some limitations and disadvantages in using TNM system to evaluate dual primary lung cancer.We used retrospective analysis to explore the independent prognostic factors of dual primary lung cancer and established the prognostic model of nomogram.Materials and methods:We obtained clinical data of patients with dual primary lung cancer(DPLC)from the Surveillance,epidemiology and end results database,the data were reclassified according to the American Joint Committee on Cancer(AJCC)eighth edition tumor staging criteria.The clinical data were put into COX univariate and multivariate regression analysis to screen out the related factors that could affect the prognosis of patients with dual primary lung cancer.Furthermore,these independent prognostic factors were included the nomogram to construct a prognostic model for dual primary lung cancer and to analyze and predict the prognosis of DPLC patients by this model.The accuracy and reliability of the prognostic model were evaluated by C-index,calibration chart,receiver operating characteristic curve(ROC),decision curve analyses(DCA)and integrated discrimination improvement(IDI)scores.To further compare the precancerous symptoms and clinical characteristics between single primary lung cancer and dual primary lung cancer,we collected complete clinical data from the Thoracic Surgery Department of Shandong Provincial Hospital,the related information of 173 patients with single primary lung cancer and 173 patients with multiple primary lung cancer were collected.The factors included sex,age,smoking status before diagnosis and chronic diseases.At the same time,chi-square test was used to evaluate the difference between multiple primary lung cancer and single primary lung cancer.Results:We collected 1419 patients with dual primary lung cancer who had complete clinical data from 2004 to 2015 through the SEER Database.Twelve clinical and pathological factors of the 1419 cases were included,these included age,race,sex,primary site,pathological type,grade,TNM stage,lymph node metastasis,radiotherapy,surgery,and the interval between the two primary tumors.We included these 12 prognostic factors in univariate and multivariate COX regression analyses,in order to analyze the prognostic factors that can independently affect the prognosis of patients with dual primary lung cancer by medical statistics.The results showed that age,sex,pathological type,TNM stage,lymph node metastasis,surgery and chemotherapy were the prognostic factors of DPLC patients(p<0.05).We then incorporated these independent prognostic factors into the nomogram and constructed a prognostic model for DPLC that could predict survival time in patients with DPLC,this greatly helps clinicians to choose treatment that is more favorable to the patient’s prognosis.To further validate the efficacy of the prognostic model,the accuracy and reliability of the prognostic model were evaluated by c-index,calibration chart,receiver operating characteristic curve(ROC),decision curve analyses(DCA)and integrated discrimination improvement(IDI)scores.The above results indicate that the new model based on the large sample size of SEER database is effective and can predict the overall survival time of patients with dual primary lung cancer accurately and individually,the model is superior to the traditional TNM staging model in evaluating the prognosis of patients.At the same time,we randomly collected information on 1419 patients with single primary lung cancer from the SEER database and used the chi-square test to assess differences.We found differences between patients with single and dual primary lung cancers in clinical characteristics.We collected preoperative information from 173 patients with multiple primary lung cancer and 173 patients with single primary lung cancer at Shandong provincial hospital to complement our findings.The chi-square test was used again to evaluate the differences in clinical characteristics.The study found that there were roughly equal percentages between men and women in the two different forms of the disease,but men were the majority of patients with single primary lung cancer.Most patients with multiprimary lung cancer have no history of smoking or have chronic diseases(such as high blood pressure,diabetes,etc.).These results indicate that the preoperative clinical features of these two diseases are different,which further suggests that the pathogenesis and etiology of these two types of lung cancer may be different.Conclusion:In this study,we found that the clinical and pathological characteristics of patients with dual primary lung cancer were different from those of patients with single primary lung cancer,and established a prognostic model of dual primary lung cancer.The study can provide accurate and individualized survival prediction for patients with dual primary lung cancer.