Factors associated with clinical presentation and survival in early-onset triple-negative breast cancer: A real-world analysis.

Abstract

e12751 Background: Early-onset triple-negative breast cancer (TNBC) is typically viewed as biologically aggressive, yet the factors underlying younger age at diagnosis and survival in these patients remain understudied. Using national real-world data, we examined clinical and sociodemographic factors associated with early-onset and overall survival (OS) among patients with TNBC. Methods: Using the National Cancer Database, we identified women younger than 40 with stage I–IV TNBC diagnosed from 2010–2019. Multivariable logistic regression evaluated factors associated with early-onset diagnosis (ages 18–40) compared to a “later-onset” reference group (ages 40–49). Multivariable Cox regression evaluated factors associated with three-year OS. Analyses adjusted for stage, diagnosis year, race/ethnicity, insurance, comorbidity index, and zip-code income quartile. Propensity-score matching (PSM) by these covariates was used to compare OS between age groups. Results: Among the final cohort with complete data for covariates, 16,529 patients were classified as early-onset. In the multivariable logistic regression, higher stage at diagnosis was strongly associated with early-onset compared with stage I (stage II: adjusted odds ratio [aOR] 1.38, 95% CI 1.31–1.46; stage III: aOR 1.50, 95% CI 1.40–1.60; stage IV: aOR 1.20, 95% CI 1.07–1.34; all p < 0.001). Compared to non-Hispanic White, Hispanic ethnicity (aOR 1.40, 95% CI 1.29–1.51, p < 0.001) and Asian American/Pacific Islander (AAPI) race (aOR 1.22, 95% CI 1.09–1.38, p < 0.001) were associated with increased odds of early-onset diagnosis, whereas non-Hispanic Black (NHB) race was associated with lower odds (aOR 0.85, 95% CI 0.80–0.90, p < 0.001). In the multivariable Cox regression, among patients with early-onset TNBC, higher stage was the strongest predictor of three-year mortality (stage IV vs stage I: adjusted hazard ratio [aHR] 30.09, 95% CI 27.64–32.75, p < 0.001). Diagnosis in 2015–2019 (versus 2010–2014: aHR 0.81, 95% CI 0.77–0.85, p < 0.001), Hispanic ethnicity (aHR 0.70, 95% CI 0.65–0.76, p < 0.001), and AAPI race (aHR 0.74, 95% CI 0.65–0.85, p < 0.001) were associated with better OS. NHB race (aHR 1.09, 95% CI 1.04–1.15, p = 0.001), uninsured status (aHR 1.56, 95% CI 1.39–1.75, p < 0.001), higher comorbidity index (≥2 vs 0: aHR 1.69, 95% CI 1.42–2.02, p < 0.001), and lower zip-code income quartile were associated with worse OS. After PSM, compared with ages 40–49, three-year mortality hazard was modestly higher for ages 30–39 (aHR 1.10, 95% CI 1.03–1.16, p = 0.003) but borderline significant for ages 20–29 (aHR 1.14, 95% CI 0.99–1.33, p = 0.08). Conclusions: Clinical and sociodemographic factors varied in their association with early-onset TNBC and OS. These findings suggest that many disparities persist in this subset of patients, and survival differences identified in our analysis may warrant further investigation.