The prevention of common skin cancers and precancers is possible by taking an inexpensive, widely available, oral pill twice daily. The pill—the vitamin B3 supplement called nicotinamide—cut the rate of new squamous-cell and basal-cell skin cancers by 23% compared with a placebo after 1 year among patients at high risk for skin cancer. Nicotinamide also reduced the risk of developing actinic keratosis, a common precancer of the skin.

The results of the phase 3 ONTRAC skin cancer prevention study were presented at ASCO 2015.

Do not confuse niacinamide with niacin, NADH, nicotinamide riboside, inositol nicotinate, or L-tryptophan. These are not the same.

The investigators emphasized that these results were achieved in individuals who previously had skin cancer and were thus at high risk for new skin cancers. The results do not apply to other patient populations.

In addition, the investigators emphasized that nicotinamide is the form of vitamin B3 that should be taken for prevention—not other forms of vitamin B, such as niacin—and that continuous treatment is advised.

“This form of prevention is safe and inexpensive, costing around $10 per month, and it is widely available. It is ready to go straight to the clinic for high-risk patients with a track record of skin cancer. This is a new opportunity for skin cancer prevention,” said lead investigator Diona Damian, MBBS, PhD, Professor of Dermatology, Dermatology University of Sydney, New South Wales, Australia. “The pill does not take the place of sunscreen use and regular skin checkups by dermatologists for people at high risk,” Dr Damian noted.

As the aging population continues to grow, basal- and squamous-cell carcinomas will become even more common than they currently are. The investigators are from Australia, which has extremely high rates of sun-induced skin cancers. A previous phase 2 study by this group showed that nicotinamide reduced the number of new actinic keratoses in Australian patients with sun-damaged skin.

The present study included 386 patients aged 30 to 91 years who had ≥2 nonmelanoma skin cancers over the past 5 years, and were therefore deemed high-risk. The patients were randomized to oral nicotinamide 500 mg twice daily or to placebo for 12 months. Dr Damian said that the patient mix reflected those seen in a typical skin cancer clinic. The average age was 66 years, and 66% of the patients were men, many with ongoing chronic comorbidities.

“These patients were typical of the ‘warts-and-all’ type of patients we see in the clinic,” Dr Damian said.

The patients were checked by a dermatologist every 3 months and suspicious lesions were biopsied. Nicotinamide reduced the rates of new basal-cell cancer and squamous-cell cancer diagnoses by 23% compared with placebo (P = .02). Nicotinamide reduced the rates of actinic keratoses (precancers) by 11% at 3 months and by approximately 15% after 12 months of treatment compared with placebo.

“This preventive treatment has no side effects. Unlike niacin, another form of vitamin B3, nicotinamide does not cause headache or increased blood pressure,” Dr Damian said.

This “is welcome news. With this study, we have a remarkably simple and inexpensive way to help people avoid repeat diagnoses of some of the most common skin cancers. With just a [twice-]daily vitamin pill, along with sun protection and regular skin cancer screenings, people at high risk for these types of skin cancers have a good preventive plan to follow,” said ASCO President Peter Paul Yu, MD, Director of Cancer Research, Palo Alto Medical Foundation, CA.