Nicotinamide reduces risk of skin cancers

by Bruce Sylvester: Treatment with nicotinamide, a form of vitamin B3, significantly lowers the risk of common, non-melanoma skin cancer in high-risk patients, researchers reported on Oct. 21, 2015 in the New England Journal of Medicine.

“This is the first clear evidence that we can reduce skin cancers using a simple vitamin, together with sensible sun protection,” said lead author, Diona Damian, MBBS, PhD, professor of dermatology at the University of Sydney in Sydney, Australia. “We hope that these findings can be immediately translated into clinical practice. However, people at high risk of skin cancer still need to practice sun safe behaviour, use sunscreens and have regular check-ups with their doctor,” she added.

The investigators enrolled 386 subjects who had been diagnosed with at least two non-melanoma skin cancers in the previous 5 years. In the phase 3, double-blind, randomized, controlled trial the researchers randomized the subjects in a 1:1 ratio to receive 500 mg of nicotinamide twice daily or placebo for 12 months.

Dermatologists evaluated each subject at 3-month intervals for 18 months.

The primary endpoint was the number of new non-melanoma skin cancers, basal-cell carcinomas and squamous-cell carcinomas, that appeared during the 12-month intervention period.

Secondary endpoints were the number of new squamous-cell carcinomas and basal-cell carcinomas and the number of actinic keratosis appearing during the 12-month intervention, the number of non-melanoma skin cancers appearing during the 6-month post-intervention, and the safety of nicotinamide.

The investigators reported that at 12 months the rate of new non-melanoma skin cancers was significantly lower, by 23% (p=0.02), in the nicotinamide group than in the placebo group.

There were similar significant differences between the cohorts with respect to new basal-cell carcinomas (20% lower rate with nicotinamide, p=0.12) and new squamous-cell carcinomas (30% lower rate, p=0.05).

Emerging actinic keratoses were 11% lower in the nicotinamide group than in the placebo group at 3 months (p=0.01), 14% lower at 6 months (p<0.001), 20% lower at 9 months (p<0.001), and 13% lower at 12 months (p=0.001).

There were no significant differences between the groups with respect to incidence or type of adverse events during the 12-month intervention period, and there were no signs  of benefit after nicotinamide treatment ended.

“Oral nicotinamide was safe and effective in reducing the rates of new non-melanoma skin cancers and actinic keratoses in high-risk patients,” the authors concluded.

The research was funded by the (Australian) National Health and Medical Research Council.