Development and validation of a SEER-based prognostic nomogram for patients with early-onset upper tract urothelial carcinoma

The study aims to investigate the clinicopathological differences between early-onset and elderly patients with upper tract urothelial carcinoma (UTUC) and to develop a nomogram for assessing the prognosis of early-onset upper tract urothelial carcinoma. Patients diagnosed with UTUC between 2004 and 2015 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The clinicopathological characteristics of early-onset and elderly patients were compared, and survival analysis was performed for both groups. Cox regression was used to identify predictors of overall survival (OS) and cancer-specific survival (CSS) in early-onset UTUC patients. Nomograms for OS and CSS were constructed and internally validated using the concordance index, decision curve analysis, receiver operating characteristic curves, and calibration plots. External validation was performed using data from 255 early-onset UTUC patients. Finally, Kaplan-Meier curves were plotted to compare survival outcomes among different risk subgroups. This study included a total of 2694 early-onset patients and 4144 elderly patients. early-onset patients were divided into training (1886 patients) and validation (808 patients) cohorts in a 7:3 ratio. Cox regression analysis identified age, tumor size, T stage, N stage, M stage histologic subtype and chemoradiotherapy as independent risk factors for OS, while age, tumor grade, tumor size, T stage, N stage, and M stage, histologic subtype and radiotherapy were independent risk factors for CSS. Nomograms of OS and CSS were constructed based on these factors. Both internal and external validations demonstrated good predictive accuracy for the nomograms. For OS, the area under the receiver operating characteristic curve (AUC) values at 1, 3, 5, and 8 years were 0.807, 0.774, 0.760, and 0.736 in the training cohort; 0.811, 0.793, 0.763, and 0.752 in the internal validation cohort; and 0.793, 0.767, 0.754, and 0.730 in the external validation cohort, respectively. Regarding CSS, the area under the receiver operating characteristic curve (AUC) values at 1, 3, 5, and 8 years were observed to be 0.834, 0.822, 0.816, and 0.792 in the training cohort; 0.863, 0.833, 0.811, and 0.820 in the internal validation cohort; and 0.819, 0.815, 0.806, and 0.780 in external validation cohort, respectively.Kaplan-Meier curves showed statistically significant differences in survival outcomes among different risk subgroups for both OS and CSS. This study developed a nomogram based on the SEER database to predict overall survival in patients with early-onset UTUC, aiming to aid in prognostic assessment and guide clinical treatment.