ArticleJournal of the National Cancer Institute2026
Use of hair straighteners and chemical relaxers and incidence of non-reproductive cancers.
Article in Journal of the National Cancer Institute, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
2 citing papers in PubMed.
- Chemicals of Concern in Chemical Hair Straightening Products: A Scoping Review.Current environmental health reports · 2026Article
- Diversity, equity, and inclusion as scientific rigor: progress during challenging times.JNCI cancer spectrum · 2026Article
Corrections and comments
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Authors and funding
7 authors.
Funding
Abstract
backgroundUse of hair straighteners and chemical relaxers has been associated with increased incidence of breast, ovarian, and uterine cancers. However, their potential association with non-reproductive cancers remains unknown, despite evidence that some ingredients in these products may be genotoxic. We therefore examined use of hair straighteners and chemical relaxers in relation to the incidence of non-reproductive cancers.
methodsWe analyzed data from 46 287 cancer-free women aged 35-74 years from the Sister Study, a US-wide cohort enrolled between 2003 and 2009. Participants reported frequency of hair straightener and chemical relaxer use in the 12 months prior to enrollment. Incident cancers (melanoma, thyroid, lung, non-Hodgkin lymphoma, leukemia, pancreatic, colorectal, and kidney cancers) were self-reported and confirmed with pathology reports when possible. We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for hair straightener and chemical relaxer use and incident cancers, adjusting for age, race and ethnicity, educational attainment, and smoking status.
resultsDuring a median follow-up of 13.1 years, use of hair straighteners and chemical relaxers was associated with a higher incidence of thyroid cancer (n = 225 cases; HR = 1.71, 95% CI = 1.01 to 2.89), non-Hodgkin lymphoma (n = 313 cases; HR = 1.62, 95% CI = 0.94 to 2.80), and pancreatic cancer (n = 138 cases; HR = 2.66, 95% CI = 1.25 to 5.66). There was little evidence of dose response with increasing frequency of use. We observed negligible or imprecise associations for the remaining cancer types.
conclusionsUse of hair straighteners and chemical relaxers may be associated with a higher incidence of thyroid cancer, non-Hodgkin lymphoma, and pancreatic cancer. Further research is needed to confirm these findings.
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