Occupational sunlight exposure linked to reduced kidney cancer risk in men

Men employed in occupations with potential exposure to high levels of sunlight have a reduced risk of kidney cancer compared with men who are less likely to be exposed to sunlight at work, according to a new study.

Research suggests that vitamin D, which is obtained from sun exposure, some foods, and from supplements, may help prevent some cancers.

Sara Karami, of the National Cancer Institute in Rockville, and her colleagues designed a study, which included 1,097 patients with kidney cancer and 1,476 individuals without cancer from four Central and Eastern European countries.

Demographic and lifetime occupational information was collected through in-person interviews and occupational sunlight exposure indices were estimated based on industry and job titles.

The investigators observed a 24% to 38% reduction in kidney cancer risk with increasing occupational sunlight exposure among male participants in the study.

No association between occupational sunlight exposure and kidney cancer risk was observed among females in the study.

The findings suggest that sunlight exposure may affect kidney cancer risk, although the authors have no explanation for the apparent differences in risk between men and women. They offer several hypotheses for the observed differences.

Biological or behavioural differences between men and women may play a role.

For example, hormonal differences may influence the body's response to sunlight exposure, females may have a higher tendency to use sunscreen on a regular basis, and men may be prone to working outdoors while shirtless.

It is also possible that the observed gender differences in risk were due to confounding by other unmeasured kidney cancer risk factors, such as recreational sunlight exposure and physical activity levels.

The study has been published early online in CANCER, a peer-reviewed journal of the American Cancer Society.