Date of Award

May 2024

Degree Type


Degree Name

Doctor of Philosophy



First Advisor

Ellen M Velie

Committee Members

Young I Cho, Phoenix Do, Dimitri Topitzes, Dorothy R Pathak


Adverse childhood experiences, Body size, Social epidemiology, Young onset breast cancer


Background: There are significant disparities in the incidence of young-onset breast cancer (YOBC) tumor subtypes and the etiology of YOBC subtypes is not well understood. Adverse childhood experiences (ACEs) have been hypothesized to increase BC risk, but to-date no studies have evaluated associations between ACEs and YOBC subtypes nor whether associations are mediated by BC risk factors, like adult body size. Here, I examine social determinants of ACEs (i.e., childhood neighborhood poverty rate (cNPR), childhood household SEP (chSEP) index, race/racism); associations between ACEs and body size and whether social determinants modify these associations; and associations between ACEs and YOBC subtypes, and whether social determinants modify and/or adult body size mediates associations. Methods: Data are from the Young Women’s Health History Study, a population-based case (n=1812)-control (n=1381) study of invasive YOBC (diagnosed aged <50 years) among non-Hispanic Black (NHB) and White (NHW) women in Los Angeles County (LA) and Metropolitan Detroit (Detroit). Cases were identified by the LA and Detroit SEER registries 2010-2015 (tumors categorized luminal A, luminal B, HER2-enriched, or triple negative (TN)) and controls were identified through area-based sampling of households from the 2010 Census. Data were recalled or measured during in-person interviews. Weighted logistic regression and structural equation modeling were conducted to address research aims. Results: Seventy-seven percent of the population-based controls recalled at least one ACE. Among these women, low chSEP was consistently associated with higher odds of ACEs; odds were similar among NHB and NHW women with low chSEP. ACEs were associated with larger adolescent and adult body size, and chSEP significantly modified the effect of ACEs: associations only reached significance among women with lower chSEP. In case-control analyses, ACEs were significantly associated with higher odds of HER2-enriched and TN tumors. There was little evidence for effect modification by social determinants. Larger adult body size negatively mediated associations between ACEs and both luminal A and B tumors. Conclusions: In this first study to evaluate associations between ACEs and YOBC subtypes, ACEs were significantly associated with increased risk of HER2-enriched and TN tumors, suggesting that ACEs could contribute to disparities in YOBC incidence.

Available for download on Friday, May 22, 2026

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