The most common form of cancer — by a large margin — is non-melanoma skin cancer. There are about two million new cases of non-melanoma skin cancer diagnosed each year, whereas there are about 1.7 million diagnoses of all other types of cancer combined.
The primary cause of nonmelanoma skin cancer is exposure to ultraviolet (UV) radiation. Vitamin B3, nicotinamide, has been shown to have a protective effect against UV radiation damage. Australian researchers set out to determine if supplementing nicotinamide could reduce risk of nonmelanoma skin cancer.
In this Phase III, double-blind, randomized, controlled trial published in 2015 in the New England Journal of Medicine, 386 people with at least two non-melanoma skin cancers in the previous 5 years were given 500 mg of nicotinamide twice daily or placebo for one year.
The primary outcomes measurement was the number of new non-melanoma skin cancers diagnosed during the study period. There was a 23% reduction in new non-melanoma skin cancers in the people taking nicotinamide compared with those taking the placebo. The nicotinamide group also had an 11% lower number of actinic keratosis (sun damage spots) compared with the placebo group at 3 months and a 13% lower incidence at 12 months. The researchers also concluded that nicotinamide had a good safety profile and there are minimal side-effects even at high doses.
The RDA for vitamin B3 is 18 mg/day for men and 14 mg/day for women so the dosage used in this study far exceeds that. The researchers came up with their dose based on previous research they had done and previous studies by other researchers.
Showing efficacy in a high-risk population like this is significant because studies indicate that someone diagnosed with non-melanoma skin cancer is 35% to 50% more likely to develop another nonmelanoma skin cancer within five years. In addition to a previous diagnosis of non-melanoma skin cancer, people who have fair skin, frequent sun exposure, a history of sunburns and a diagnosis of HPV are also at risk.
The researchers conclude that nicotinamide is an inexpensive “new opportunity for chemoprevention of nonmelanoma skin cancers that is readily translatable into clinical practice.”