Associations of hair dye and relaxer use with breast tumor clinicopathologic features: Findings from the Women's circle of Health Study

Rohan Rao, Jasmine A. McDonald, Emily S. Barrett, Patricia Greenberg, Dede K. Teteh, Susanne B. Montgomery, Bo Qin, Yong Lin, Chi Chen Hong, Christine B. Ambrosone, Kitaw Demissie, Elisa V. Bandera, Adana A.M. Llanos

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background: Building upon our earlier findings of significant associations between hair dye and relaxer use with increased breast cancer risk, we evaluated associations of select characteristics of use with breast tumor clinicopathology. Methods: Using multivariable-adjusted models we examined the associations of interest in a case-only study of 2998 women with breast cancer, overall and stratified by race and estrogen receptor (ER) status, addressing multiple comparisons using Bonferroni correction. Results: Compared to salon application of permanent hair dye, home kit and combination application (both salon and home kit application) were associated with increased odds of poorly differentiated tumors in the overall sample. This association was consistent among Black (home kit: OR 2.22, 95 % CI: 1.21–5.00; combination: OR 2.46, 95 % CI: 1.21–5.00), but not White women, and among ER+ (home kit: OR 1.47, 95 % CI: 0.82–2.63; combination: OR 2.98, 95 % CI: 1.62–5.49) but not ER-cases. Combination application of relaxers was associated with increased odds of tumors >2.0 cm vs. <1.0 cm (OR = 1.82, 95 % CI: 1.23–2.69). Longer duration and earlier use of relaxers and combination application of permanent hair dyes and relaxers were associated with breast tumor features including higher tumor grade and larger tumor size, which often denote more aggressive phenotypes, although the findings did not maintain significance with Bonferroni correction. Conclusions: These novel data support reported associations between hair dye and relaxer use with breast cancer, showing for the first time, associations with breast tumor clinicopathologic features. Improved hair product exposure measurement is essential for fully understanding the impact of these environmental exposure with breast cancer and to guide risk reduction strategies in the future.

Original languageEnglish (US)
Article number111863
JournalEnvironmental research
StatePublished - Jan 2022

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Environmental Science(all)


  • Breast cancer
  • Breast tumor features
  • Hair dye
  • Hair products
  • Hair relaxer
  • Personal care products


Dive into the research topics of 'Associations of hair dye and relaxer use with breast tumor clinicopathologic features: Findings from the Women's circle of Health Study'. Together they form a unique fingerprint.

Cite this