A new study published in the December 21 issue of the Journal of the National Cancer Institute says that exposure to ultraviolet B (UV-B) radiation reduces the ability to repair the chromosomal damage caused to the skin and hence increases the risk of developing basal cell carcinoma and squamous cell carcinoma.
UV radiation is the commonest cause of skin cancer and is responsible for breaking DNA strands in exposed skin cells. Patients who have a condition called xeroderma pigmentosum are unable to repair these broken strands and hence are at increased risk of developing skin cancer. Li-E Wang, M.D., and Qingyi Wei, M.D., Ph.D., of the University of Texas M. D. Anderson Cancer Center in Houston, and colleagues measured the chromatid breaks in a study involving chromatid breaks having melanoma and non-melanoma skin cancers. 329 cancer-free patients were used as a control.
researchers found that as the number of chromatid breaks increased so did the risk of developing skin cancer, but not melanoma. "These findings suggest that in vitro UVB-induced mutagen sensitivity reflects susceptibility to nonmelanoma skin cancer but not cutaneous malignant melanoma," the authors concluded.
Journal of the National Cancer Institute