Survival and prognosis of metastatic breast cancer in young women: SEER 2010-2015

Although breast cancer in young women (BCYW) is not as common as in older individuals, the incidence of BCYW is increasing. Due to the particular considerations regarding pregnancy, fertility preservation, early menopause, body image, lactation, and quality of life, BCYW deserves unique management. We sought to estimate the survival and prognosis of such patients. In this article, we extracted 9761 primary breast cancer patients' data between 2010 and 2015 from the Surveillance Epidemiology and End Results (SEER) database. We included patients under 70 years and divided them into two groups by age (＜40 vs. 40-69 years). We defined the clinicopathologic characteristics, comprehensively analyzed and compared the OS and BCSS of breast cancer between two age groups among tumor subtypes. Patients under 40 years have longer OS and BCSS than older patients, while these survival benefits are limited in HR+ or/and HER2+ patients, except for TNBC, which needs further investigation. In addition, we developed an efficient predictive nomogram to predict 1-, 3- and 5-year OS of metastatic BCYW. These nomograms can aid oncologists in distinguishing, assessing and evaluating the risk and prognosis of metastatic BCYW, which can help oncologists select the next treatment strategies for BCYW.