Abstract P6-08-08: Age-Related differences in clinicopathologic features and survival amongst women with triple negative breast cancer: A population-based study
Authors: Wong SM , Boileau J-F , Martel K , Ferrario C , Basik M 
Published: February 2018

INTRODUCTION: Women with triple-negative breast cancers (TNBC) have a tendency to present at younger ages and with more advanced disease. We sought to comprehensively evaluate the characteristic features, surgical management, and survival outcomes of a large, population-based cohort of patients with TNBC according to age at diagnosis.

METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER) database to identify women aged 18 years or older with a diagnosis of TNBC between 2010-2014. Clinicopathologic and treatment level variables were compared amongst TNBC patients according to age at the time of TNBC diagnosis. The Kaplan-Meier method and Cox PH Regression was then used to examine short-term breast cancer-specific survival (BCSS) outcomes.

RESULTS: Between 2010-2014, 214,138 women were diagnosed with breast cancer, of which 23,614 (11.13%) had TNBC. The median age at TNBC diagnosis was 57.7 years. Younger TNBC patients were more likely to be of African American (&lt;40 years, 20.1% vs. ≥70 years, 15.5%; p&lt;0.001) or Hispanic race (&lt;40 years, 21.9% vs. ≥70 years, 7.0%; p&lt;0.001), diagnosed with larger tumors (T2-T3; &lt;40 years, 70.2%; 40-49 years, 61.7%; 50-59 years, 55%; 60-69 years, 48.1%; ≥70 years, 49.5%; p&lt;0.001) and present with lymph node positive disease (&lt;40 years, 36.7%; 40-49 years, 34.8%; 50-59 years, 32.5%; 60-69 years, 27.5%; ≥70 years, 27.9%; p&lt;0.001). With respect to local therapy, younger women also had a greater tendency to undergo bilateral mastectomy (&lt;40 years, 34.3%; 40-49 years, 23.1%; 50-59 years, 13.4%; 60-69 years, 8.4%; ≥70 years, 3.3%; p&lt;0.001). The estimated one and four-year BCSS for the entire cohort was 94.4% and 79.7%, respectively, with the youngest women &lt;40 years and older women ≥70 years demonstrating the poorest unadjusted BCSS at four years (&lt;40 years, 76.95%; 40-49 years, 82.1%; 50-59 years 80.9%; 60-69 years 81.7%; ≥70 years, 78.6%; log rank p&lt;0.001). In Cox PH analysis adjusting for race, stage, pathologic features, and local therapy, age greater than 70 years remained significantly associated with worse cancer-specific survival (HR1.60, 95% CI 1.39-1.84).

CONCLUSION: In the population studied, more than 40% of very young women with TNBC are of African American or Hispanic race. When compared to older ages, younger women with TNBC are more likely to receive bilateral mastectomy and have more advanced stage at presentation. Women at both age extremes (≥70 years and &lt;40 years at diagnosis) demonstrate worse cancer-specific survival outcomes. In older women, this may be due to undertreatment, and in younger women, to delays in diagnosis and/or worse tumor biology. Further studies are needed to evaluate age-related discrepancies in local and systemic therapy and cancer-specific survival in TNBC.

Citation Format: Wong SM, Boileau J-F, Martel K, Ferrario C, Basik M. Age-Related differences in clinicopathologic features and survival amongst women with triple negative breast cancer: A population-based study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-08-08.