Clinical Features and Outcomes of Triple-Negative Breast Cancer Among Latin American Adolescents and Young Adults Compared to Middle-Aged and Elder Females: A Cohort Analysis Over 15 Years.

Outcomes of females with triple-negative breast cancer (TNBC) are rarely explored in adolescents and young adults (AYAs). We compared clinical and survival outcomes of Latin American AYAs (≤39 years) with middle-aged (40-59 years) and older (≥60 years) females with TNBC by cancer stage. We performed a single-center retrospective cohort study among treated females with cancer stages I-III diagnosed from 2000 to 2014 in Peru. We evaluated overall survival (OS) and event-free survival (EFS). Time-to-event methods were used for analyses. Of 1582 females with TNBC, 350 (22%) were AYAs, 887 (56%) were middle-aged, and 345 (22%) were older women. Tumor size >5 cm, histological grade III, and brain metastasis were more common features in AYAs. AYAs were treated more frequently with neoadjuvant chemotherapy. With a median follow-up of 102 months, the 5-year OS/EFS for AYAs was 55%/53%, similar to middle-aged (54%/49%) and older females (56%/51%). AYAs were not at higher risk for decreased OS or EFS in the multivariable Cox analysis. Our findings remained consistent by cancer stage. Although Latin American AYAs with TNBC have more aggressive clinical features at diagnosis, survival outcomes were comparable with middle-aged and older women with TNBC, suggesting that age is not a risk factor for worse survival outcomes if treatment is given according to cancer stage. Our findings should be interpreted with caution given the lack of information on certain covariates such as comorbidities. Strategies for early detection in primary care and prompt referral for treatment initiation should be developed.