Dermatologists have long recommended the vitamin B3 derivative nicotinamide for patients with a history of skin cancers, following a 2015 clinical trial of 386 participants that showed fewer new tumours among those taking the supplement.
But validation in a much larger population has been limited, largely because nicotinamide is available over the counter and its use is often not captured in medical records.
A recent US large-scale study published in JAMA Dermatology now provides large-scale evidence that taking 500mg of nicotinamide twice a day can reduce the risk of developing new non-melanoma skin cancers in high-risk individuals.
Researchers at Vanderbilt University Medical Center in Nashville, Tennessee analysed electronic health records of 33,822 US veterans, of whom 12,287 had been prescribed nicotinamide 500mg twice daily for at least 30 days, and were compared with 21,479 matched unexposed controls. Overall, nicotinamide use was associated with a 14 percent reduction in new keratinocyte skin cancer diagnoses, including both basal-cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC).
More strikingly, when nicotinamide was initiated after a first skin cancer diagnosis, the risk reduction rose to 54 percent.
The protective effect was greatest for cSCC, the faster-growing subtype among non-melanoma skin cancers. The benefit decreased when supplementation was started after multiple prior skin cancers, and no statistically significant overall reduction was observed among solid-organ transplant recipients – though early use did show a reduced incidence of cSCC in that subset.
Lead author Lee Wheless, MD, PhD, told medpagetoday.com: ‘We currently don’t have formal guidelines as to when to treat with nicotinamide, though in certain high-risk populations, such as those with field cancerisation, it has been suggested to start after the second skin cancer or later. These results suggest that we need to broaden the scope of who needs earlier intervention, while also providing some pretty strong evidence that nicotinamide is in fact effective at reducing the risk of skin cancer.’
