Construction Of Nomogram Of Patients With Invasive Extramammary Paget Disease And Evaluation Of Treatment Prognosis Based On SEER Database

Objective Extramammary Paget disease(EMPD)was a skin malignant tumor originating from the epithelium,which occured in areas rich in apocrine sweat glands,such as the vulva,penis or scrotum,armpits,and groin.So far,no standardized diagnosis and treatment guidelines had been established for the diagnosis,treatment and follow-up of EMPD.This article aimed to construct a nomogram survival prediction model to evaluate the prognosis of EMPD patients through the SEER database,and to analyze the effects of different treatment methods on the prognosis of EMPD patients,so as to provide a basis for the establishment of standardized treatment guidelines for EMPD.Materials A total of 2683 patients with invasive extramammary Paget disease diagnosed from 1975 to 2016 were collected from the Surveillance,Epidemiology,and End Results(SEER)of the National Cancer Institute in the United States.Randomly divided into training group and verification group according to 1:1.Univariate and multivariate Cox proportional hazards regression models were used to analyze and determine independent factors affecting the prognosis of patients in the training group.The above factors were included and constructed to predict the 5-year and 10-year overall survival(OS)nomograms of EMPD patients.Validate the nomogram internally and externally through the C-index(the concordance index(C-index)),calibration curve and the area under the receiver operating characteristic curve(AUC)to evaluate its prediction value.Finally,the Kaplan-Meier curve was used to compare the effects of different treatment methods on the prognosis of EMPD patients and the effects of different clinicopathological parameters on the prognosis.Results1.A total of 2683 patients were randomly assigned to the training group(n=1342)or validation group(n=1341).Univariate and multivariate Cox proportional risk regression models showed that age,sex,race,tumor stage,and treatment were correlated with OS in EMPD patients(P<0.05).Sex,tumor size,combined with other malignancies,and tumor stage were associated with cancer specific survival(CSS)in EMPD patients(P < 0.05).2.The above factors were incorporated into and constructed a nomogram to predict the5-year and 10-year OS of EMPD patients.The C index of OS in the training group was 0.732(95%CI: 0.704-0.76),and that in the validation group was 0.766(95%CI: 0.739-0.793).The calibration curves of the two groups also showed good consistency.At the same time,the areas under the ROC curves of the 5-year and 10-year OS predicted by internal verification were0.744 and 0.79,and the areas under the ROC curves of the 5-year and 10-year OS predicted by external verification were 0.768 and 0.798.3.Survival analysis showed that EMPD patients treated with surgery had the best prognosis(P < 0.001),with 5-year and 10-year overall survival of 78.26% and 58.47%,respectively,while patients treated with radiotherapy and chemotherapy had poor prognosis.Among surgical patients,female patients and local tumor staging had a better prognosis,while tumor size than 7.6cm and perianal EMPD had a poorer prognosis.There was no statistical difference in the effects of age and race on the CSS of patients.In female vulva EMPD patients,the CSS of surgical treatment patients was significantly better than that of patients receiving radiotherapy and chemotherapy(P < 0.001),and there was no statistical difference in the effect of treatment methods on the CSS of male penile or scrotal EMPD patients.Patients receiving radiotherapy and chemotherapy had a poor prognosis regardless of the presence of other malignancies(P < 0.001).Conclusions1.The Nomogram for the survival prognosis of EMPD patients established in this study has certain predictive value,which will help clinicians to provide a better and more accurate prognosis assessment for EMPD patients and to identify high-risk EMPD patients.2.The overall prognosis of patients with invasive EMPD is good.For early EMPD patients,with or without other malignant tumors,surgical treatment has the best prognosis,and the prognosis is acceptable without intervention.The advanced patients received radiotherapy and chemotherapy have a poor prognosis.