Radon is a well-established cause of lung cancer, but its potential role in other malignancies remains less clearly defined. A large prospective cohort study published in JAMA Network Open has now explored whether residential radon exposure may be associated with ovarian cancer risk in postmenopausal women.
The study analysed data from 127,547 participants in the Women’s Health Initiative, with a mean follow-up of 17.7 years, examining associations between estimated residential radon levels and both ovarian cancer incidence and mortality.
CLINICAL SUMMARY
What was examined
A prospective cohort study assessed the association between residential radon exposure and ovarian cancer risk in postmenopausal women.
Key findings
- High residential radon exposure was associated with increased ovarian cancer incidence (HR 1.31)
- Stronger association observed for serous ovarian cancer
- Increased ovarian cancer mortality was also observed in high-radon areas
Clinical implications
- Supports a potential link between environmental radiation exposure and ovarian cancer
- Highlights radon as a modifiable risk factor
- May inform future prevention strategies and public health policy
Women living in areas with higher estimated residential radon concentrations, defined as greater than 4 pCi/L, were at increased risk of ovarian cancer compared with those in low-exposure areas (hazard ratio [HR] 1.31). No statistically significant increase in risk was observed among women with medium levels of radon exposure.
The association appeared to be more pronounced for serous ovarian cancer, the most common and aggressive histological subtype, with a hazard ratio of 1.38 for high versus low exposure. In addition, ovarian cancer mortality was higher among women residing in areas with elevated radon levels (HR 1.31), suggesting a potential impact not only on incidence but also on disease outcomes.
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These findings point to a possible role for environmental radiation exposure in ovarian carcinogenesis and raise the prospect that radon, a common environmental exposure that can be mitigated, could contribute to disease risk. While the observational nature of the study precludes conclusions about causality, the results highlight the need for further research to clarify the biological mechanisms involved and to determine whether radon mitigation strategies could have a role in cancer prevention.
Paper: Williamson MR, Whitsel EA, Smith RL, et al. Residential Radon Levels and Ovarian Cancer Among Postmenopausal Women. JAMA Netw Open. 2026;9(4):e268641. Access online here.
