Abstract 6191: Associations of alcohol consumption with expression of CD44, CD24, and ALDH1A1 stem cell markers in incident benign breast biopsy samples

Abstract Purpose: We investigated the associations of alcohol consumption with expressions of stem cell markers CD44, CD24, and ALDH1A1 in cases of incident benign breast disease. Methods: This study included 721 cancer-free women with biopsy-confirmed benign breast disease (BBD) within the Nurses’ Health Study II cohort. Histologically normal breast tissue cores were used to construct tissue microarrays (TMAs). Immunohistochemistry (IHC) was performed on TMA sections to analyze the expression of stem cell markers. For each core, the IHC expression was assessed using semi-automated software and reported as the % of positively stained cells for each of the markers out of the total cell count. All expression measures were log-transformed for analysis. Alcohol consumption was obtained from semi-quantitative food frequency questionnaires. Other covariate information was collected on the initial questionnaire and updated biennially thereafter. We examined associations for recent (at the time of biopsy) and cumulative average alcohol consumption (from all questionnaires before the biopsy), modeled as a continuous variable (drinks/day). Generalized linear regression was used to examine the associations of alcohol with each marker’s expression (within stroma and epithelium), while adjusting for known breast cancer risk factors and BBD subtype. Results: In this study of 721 cancer-free women, the average age at the time of biopsy was 44 (range 27-63), with the majority of participants being premenopausal at the time of biopsy (81.28%). Recent and cumulative average alcohol consumption were not associated with expression of CD44, CD24, or ALDH1A1 in stroma (recent: β per drink/day=0.08, 95% Confidence Interval [CI] -0.16, 0.32; β=-0.03, 95% CI -0.11, 0.05; β=0.01, 95% CI -0.26, 0.29, respectively; cumulative average: β=-0.09, 95% CI -0.38, 0.19; β=-0.01, 95% CI -0.10, 0.08; β=-0.04, 95% CI -0.36, 0.27, respectively) or epithelium (recent: β=0.08, 95% CI -0.04, 0.21; β=0.02, 95% CI -0.01, 0.06; β=0.23x10-2, 95% CI -0.15, 0.15, respectively; cumulative average: β=-0.06, 95% CI -0.08, 0.20; β=0.04, 95% CI -0.01, 0.08; β=-0.01, 95% CI -0.18, 0.17, respectively). Conclusion: Our findings suggest that alcohol use is not associated with the expression of CD44, CD24, and ALDH1A1 in histologically normal breast tissue from benign biopsies. Citation Format: Rulla M. Tamimi, Maisey Ratcliffe, Yu Jing J. Heng, Brian Sardella, Lusine Yaghjyan. Associations of alcohol consumption with expression of CD44, CD24, and ALDH1A1 stem cell markers in incident benign breast biopsy samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6191.