Primary Breast Malignancy in Children and Adolescents: A Population-Based Study.

Primary breast cancer in children and adolescents is extremely uncommon and presents with different characteristics from those found in adult women. We aimed to conduct a population-based cohort study to predict overall survival (OS) in pediatric patients with breast cancer. Demographic and clinicopathological data on pediatric breast cancer patients were obtained from the Surveillance, Epidemiology, and End Results database (2000-2019). The survival rates were measured using the Kaplan-Meier method. Univariate survival analysis used the log-rank test, while multivariate analysis used Cox proportional hazards regression to identify factors influencing OS. Furthermore, we created a nomogram to predict OS in pediatric patients. A total of 115 pediatric patients were analyzed, with a median age at diagnosis of 18 years (range: 2-19 years). In terms of tumor grade, 27 (23.4%) patients had well or moderately differentiated tumors and 32 (27.8%) had poorly or undifferentiated tumors. The predominant histological type was phyllodes tumor, accounting for 36.5%, followed by infiltrating duct carcinoma at 31.3%, and other types at 32.2%. The SEER and M stages were substantial independent indicators of OS. A nomogram was created to predict OS in pediatric breast cancer patients. Our findings confirmed that the SEER stage and M stage were the most critical predictors of OS in pediatric patients with breast cancer. By focusing on this rare demographic, our study fills an important gap in the literature, as there are few comprehensive studies available that explore a prognosis in pediatric breast cancer.