Clinical Characteristics and Long-Term Outcomes of Young Women With Breast Cancer: A Multicenter Study From Uruguay

Breast cancer in women aged ≤40 years is uncommon but clinically challenging, often associated with aggressive pathological features and advanced-stage diagnosis. In Latin America, real-world data on long-term outcomes in this population remain limited. This study aimed to describe clinicopathological characteristics, treatment patterns, and survival outcomes of young women with breast cancer treated in Uruguay.

We conducted a multicenter retrospective cohort study including women aged 18-40 years diagnosed with invasive breast cancer between 2006 and 2024 at two public referral centers. Clinical, pathological, and treatment data were collected from medical records. Overall survival (OS) and disease-free survival (DFS) were estimated using Kaplan-Meier analysis.

A total of 267 patients were included (mean age at diagnosis, 34.8 years). Invasive ductal carcinoma was the predominant histology (85.8%), with a high proportion of grade III tumors (39.3%). The most common biological subtype was luminal (48.8%), followed by HER2-positive (27.7%) and triple-negative disease (17.2%). Stage II disease was most frequent (40.4%), while 28.7% of patients presented with stage III disease. Modified radical mastectomy was the most commonly performed surgical procedure (38.2%). Most patients received surgery, radiotherapy, and systemic therapy according to recurrence risk. With a median follow-up of 52.3 months, estimated OS was 84.8% at 5 years and 80.9% at 10 years. Survival outcomes differed significantly according to clinical stage but not biological subtype.

Young women with breast cancer in Uruguay frequently present with aggressive tumor features and advanced disease at diagnosis. Nevertheless, when managed within a multidisciplinary framework and treated according to current standards of care, long-term survival outcomes are favorable and comparable to international reports. These findings underscore the importance of early detection strategies and equitable access to guideline-based care in middle-income countries.