Abstract PO-181: Associations of characteristics of hair dye and relaxer use with tumor clinicopathologic features among Black and White women with breast cancer
Authors: Rao Rohan , McDonald Jasmine A. , Barrett Emily S. , Teteh Dede , Montgomery Susanne , Qin Bo , Lin Yong , Hong Chi-Chen , Ambrosone Christine B. , Demisse Kitaw , Bandera Elisa V. , Llanos Adana A.M. 
Published: December 2020

Abstract
Introduction: In our previous findings from the Women’s Circle of Health Study (WCHS), we observed statistically significant associations between use of hair dye and relaxer, which contain potentially mutagenic and endocrine-disrupting chemicals, and increased breast cancer risk. In the current analysis, we sought to expand upon our earlier findings by assessing associations between hair product use and breast tumor clinicopathology. Methods: Risk factor data (including characteristics of hair product use) were collected through in-person interviews, and tumor clinicopathology data were abstracted from available pathology records of 2,998 breast cancer cases (2,227 Black, 771 White). Associations between hair product use and tumor clinicopathology were analyzed using multivariable-adjusted, binomial and multinomial logistic regression models. Further analysis was performed in subsets by race and estrogen receptor (ER) status. Results: Numerous characteristics of hair product use were associated with more aggressive tumor features. Longer (&gt;10 years) use of relaxers and earlier exposure to relaxers (≤12 years old at first use) were associated with increased odds of poorly differentiated tumors (OR 2.15, 95% CI: 1.08-4.28 and OR 2.00, 95% CI: 1.05-3.82, respectively).
History of regular relaxer use (OR 1.51, 95% CI: 1.23-1.87) and dual use of both hair dyes and relaxers (OR 1.40, 95% CI: 1.02-1.92) were associated with increased odds of ER- status. Compared to sole salon application, utilization of both salon and home- kit application types for hair dyes was associated with increased odds of higher tumor grade (moderately differentiated: OR 1.74, 95% CI: 1.05-2.87; poorly differentiated: OR 2.52, 95% CI: 1.51-4.20). These associations were consistent among Black, but not White, women. Combination use of salon and home-kit relaxer application types was associated with increased odds of tumors &gt;2.0 cm (OR 1.88, 95% CI: 1.27-2.77). Conclusions: While recent research has supported a connection between hair product use and breast cancer risk, this is the first study to examine the associations of hair product use with breast tumor features. Our findings showed that certain characteristics, particularly the magnitude of exposure to these products and application types of hair dye and relaxer, are associated with tumor features that are indicative of more aggressive phenotypes, including higher grade and ER- status. These findings generate new hypotheses about the potential impact of hair product use on breast cancer outcomes, warranting further study.
Citation Format: Rohan Rao, Jasmine A. McDonald, Emily S. Barrett, Dede Teteh, Susanne Montgomery, Bo Qin, Yong Lin, Chi-Chen Hong, Christine B. Ambrosone, Kitaw Demisse, Elisa V. Bandera, Adana A.M. Llanos. Associations of characteristics of hair dye and relaxer use with tumor clinicopathologic features among Black and White women with breast cancer [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-181.