Browsing by Author "Hirko, Kelly A."

Now showing 1 - 2 of 2

Adiposity throughout Adulthood and Risk of Young-Onset Breast Cancer Tumor Subtypes in the Young Women’s Health History Study
(American Association for Cancer Research, 2024-10) Marcus Post, Lydia; Pathak, Dorothy R.; Hamilton, Ann S.; Hirko, Kelly A.; Houang, Richard T.; Guseman, Emily H.; Sanfelippo, Dan; Carnegie, Nicole Bohme; Olson, L. Karl; Schwartz, Ann G.; Velie, Ellen M.
Background: The role of adult adiposity in young-onset breast cancer (YOBC) subtype risk is not well understood. Methods: In this population-based case (n = 1812)–control (n = 1,381) study of invasive YOBC (ages <50 years), cases were identified from the Los Angeles County and Metropolitan Detroit Surveillance, Epidemiology, and End Results registries, 2010 to 2015. Area-based, frequency-matched controls were sampled from the 2010 Census. General adiposity [body mass index (BMI)] and central adiposity (waist circumference and waist-to-height ratio) across adulthood and covariates were collected from in-person interviews and measurements. ORs and 95% confidence intervals (CI) for adiposity and YOBC tumor subtypes [i.e., luminal A, luminal B, HER2+, and triple negative (TN)] were calculated, overall and by parity, using multivariable weighted logistic regression. Results: Obese young adult BMI was inversely associated with luminal A YOBC (OR = 0.35, 95% CI, 0.16–0.79); other subtype associations were nonsignificant. Similarly, adult overweight and obese BMIs were inversely associated with luminal A (OR = 0.66, 95% CI, 0.48–0.91 and OR = 0.59, 95% CI, 0.46–0.87, respectively), but not other subtypes. Conversely, larger waist circumference was associated with higher odds of luminal B and TN YOBC (OR = 1.48, 95% CI, 1.01–2.15 and OR = 2.48, 95% CI, 1.52–3.88, respectively), but not other subtypes (with similar results for weight-to-height ratio); highest odds were among parous women. Conclusions: Findings show greater general adult adiposity is associated with reduced odds of luminal A YOBC, whereas greater central adiposity is associated with increased odds of luminal B and TN YOBC, particularly among parous women. Impact: Additional studies of central adiposity and YOBC subtype risk, especially incorporating pregnancy history, are warranted.
Lifetime alcohol consumption patterns and young-onset breast cancer by subtype among Non-Hispanic Black and White women in the Young Women’s Health History Study
(Springer Nature, 2023-10) Hirko, Kelly A.; Lucas, Darek R.; Pathak, Dorothy R.; Hamilton, Ann S.; Post, Lydia M.; Ihenacho, Ugonna; Carnegie, Nicole Bohme; Houang, Richard T.; Schwartz, Kendra; Velie, Ellen M.
Purpose. The role of alcohol in young-onset breast cancer (YOBC) is unclear. We examined associations between lifetime alcohol consumption and YOBC in the Young Women’s Health History Study, a population-based case–control study of breast cancer among Non-Hispanic Black and White women < 50 years of age. Methods. Breast cancer cases (n = 1,812) were diagnosed in the Metropolitan Detroit and Los Angeles County SEER registry areas, 2010–2015. Controls (n = 1,381) were identified through area-based sampling and were frequency-matched to cases by age, site, and race. Alcohol consumption and covariates were collected from in-person interviews. Weighted multivariable logistic regression was conducted to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for associations between alcohol consumption and YOBC overall and by subtype (Luminal A, Luminal B, HER2, or triple negative). Results. Lifetime alcohol consumption was not associated with YOBC overall or with subtypes (all ptrend ≥ 0.13). Similarly, alcohol consumption in adolescence, young and middle adulthood was not associated with YOBC (all ptrend ≥ 0.09). An inverse association with triple-negative YOBC, however, was observed for younger age at alcohol use initiation (< 18 years vs. no consumption), aOR (95% CI) = 0.62 (0.42, 0.93). No evidence of statistical interaction by race or household poverty was observed. Conclusions. Our findings suggest alcohol consumption has a different association with YOBC than postmenopausal breast cancer—lifetime consumption was not linked to increased risk and younger age at alcohol use initiation was associated with a decreased risk of triple-negative YOBC. Future studies on alcohol consumption in YOBC subtypes are warranted.