| ObjectiveThe rarity of Neuroendocrine Tumors of the Thymus(NETTs)and the lack of prospective clinical trials have led to limited understanding of their biology,treatment information and prognosis.At present,the main treatment approaches for thymic neuroendocrine tumors include:surgical treatment,radiotherapy and chemotherapy.Among them,radical surgical treatment may be the preferred treatment strategy for most patients,while for some patients with larger tumors,receiving adjuvant treatment after surgical resection may prevent the recurrence of the disease and enable them to obtain more survival benefits.The purpose of this study is to evaluate the 254 cases of NETTs treated in the US SEER(surveillance,epidemiology and final results)database from 1988 to 2016 and 25 patients in our center between January 2014 and December 2019.Retrospective analysis and long-term follow-up of clinical data of patients.Explore the clinical characteristics and prognostic survival of patients with thymic neuroendocrine tumors(NETTs).And establish and verify the model of nomogram to predict the prognosis of patients,and provide certain reference for specific clinical patients with corresponding individualized treatment strategies.MethodsPatients with NETTs were included in the U.S.SEER(Surveillance,Epidemiology,and End Results)database between 1988 and 2016.All patients received treatment and had clear histopathological diagnosis and clinical staging.Through database query,telephone and outpatient follow-up,the clinical baseline data of the study subjects were obtained.These data include gender,age,race,tissue grade,size,marriage,American Joint Committee on Cancer(AJCC)T staging(degree of invasion),surgical status,whether or not to undergo radiotherapy and chemotherapy,and survival related information.Survival time is defined from the date of diagnosis to the date of death or the date of the last follow-up.Patients who survived or died of other causes at the end of follow-up were defined as censored data.Overall survival(OS)was estimated using the Kaplan-Meier method with the log-rank test.Univariate and multivariate Cox proportional risk regression analysis was performed to determine independent prognostic factors,and the nomogram model of NETTs was established.Consistency index and calibration curve were used to evaluate the prediction accuracy of the model.External validation of the nomogram was performed using data from our center.In order to facilitate clinical use,we have established a web server on this basis.Results254 patients with NETTs were collected in the SEER database.In the multivariate analysis,T stage,tumor grade,surgery and chemotherapy were found to be independent factors affecting the prognosis of patients(all P<0.05).A nomogram model was constructed based on these variables,and its C-index was 0.707(0.661-0.752).The results of the consistency index showed that the nomogram model showed better discrimination ability than the TNM staging system in the 8th edition 0.696(95%CI 0.647-0.745)and MK staging system 0.697(95%CI 0.648-0.746).Calibration curves show that the nomogram model can accurately predict patient prognosis.Finally,we built an online web calculator based on the nomogram model to facilitate the calculation and analysis of clinical data.ConclusionsNETTs are a rare aggressive tumor with a poor prognosis.According to our research,its possible significant effects on tumors include T staging,histological classification of tumors,whether it can be surgically removed,and whether adjuvant chemotherapy is required.Based on the clinical risk factors found in the SEER database,the first practical nomogram to objectively and accurately predict the long-term OS of individualized NETTs patients was established.In addition,the external queue verification results show that the nomogram performs well,with high accuracy and reliability.At the same time,the C index of the prediction model which is significantly higher than the AJCC eighth edition staging system and MK staging system.Therefore,we believe that compared with the TNM staging system and some previous prognostic models,the established nomogram model represents a more accurate prognostic model.And as a nomogram validated based on external data,we believe that doctors can use this model to more accurately assess the long-term survival status of patients and provide appropriate individualized treatment strategies for specific patients. |
