Prevention of common skin cancers and precancers is possible by taking an inexpensive, widely available oral pill twice a day. The pill, a vitamin B3 supplement called nicotinamide, cut the rate of new squamous and basal cell skin cancers by 23% compared with placebo after 1 year. Nicotinamide also reduced the risk of developing actinic keratosis, a common precancer of the skin.
These findings, from the phase 3 ONTRAC skin cancer prevention study, have the potential to lower healthcare costs. In the United States, nonmelanoma skin cancer is diagnosed in approximately 5 million people each year.
The authors emphasize that these results were achieved in people who had had previous skin cancer and were thus at high risk of developing new skin cancers. The results do not apply to other patient populations. Also, they emphasized that nicotinamide is the only 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 author Diona Damian, MBBS, PhD, Professor of Dermatology at the University of Sydney, Australia. “The pill does not take the place of sunscreen use and regular skin checkups by dermatologists for people at high risk,” she told listeners.
As the aging population continues to grow, basal and squamous cell carcinomas will become even more common than they are now. The authors are from Australia, which has extremely high rates of sun-induced skin cancers. A previous phase 2 study by this group found that nicotinamide reduced the numbers of new actinic keratoses in Australian patients with sun-damaged skin.
The phase 3 study included 386 patients who had had ?2 nonmelanoma skin cancers over the past 5 years and were therefore deemed to be at high risk. Patients were randomized to daily oral nicotinamide 500 mg/bid or placebo for 12 months. Damian said the patient mix reflected those seen in a typical skin cancer clinic. Average age was 66 years (range, 30-91 years), and two-thirds were men, many with ongoing chronic comorbidities.
“These patients were typical of the ‘warts and all’ type of patients we see in the clinic,” she said.
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 by 11% at 3 months and by around 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,” 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.
