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Soo Park, MD
Soo Park, MD
Posted: Friday, September 26, 2025
In a retrospective cohort study published in JAMA Dermatology, Breglio et al reported that nicotinamide, an oral vitamin B3 derivative, may reduce the risk of subsequent skin cancers in those with at least one prior skin cancer and among some solid organ transplant recipients (SOTRs) when initiated soon after the first skin cancer diagnosis.
The analysis included 33,822 veterans with at least one prior nonmelanoma skin cancer. Of these, 12,287 (mean age = 77.2 years) received nicotinamide at 500 mg twice daily for ≥ 30 days compared with 21,535 (mean age = 76.9 years) matched controls. The primary endpoint of the study was the time to the next skin cancer after baseline.
After adjusting for residual confounding using stratified Cox models, the study authors found a 14% overall reduction in the rate of new skin cancers among patients who initiated nicotinamide compared with unexposed patients (hazard ratio [HR] = 0.86; 95% confidence interval [CI] = 0.82–0.89). The strongest benefit (22%) was observed for cutaneous squamous cell carcinoma (HR = 0.78; 95% CI = 0.75–0.82), while no reduction was seen for basal cell carcinoma.
Despite prior evidence suggesting that nicotinamide may increase the rate of cancer growth and metastasis, the study authors found no evidence to support this concern. “Our results argued that earlier initiation of chemoprevention with nicotinamide might yield better results,” they stated.
Timing of treatment was a critical factor in the study. Initiation of nicotinamide after the first skin cancer was linked with nearly a 50% reduction in skin cancer risk, although benefit declined with each subsequent skin cancer.
Results were mixed for SOTRs. While there was no significant association of nicotinamide and skin cancer reduction among SOTRs overall, there was a significant reduction in the risk of cutaneous squamous cell carcinoma among SOTRs with only one or two prior skin cancers (HR = 0.47; 95% CI = 0.58–0.69).
As the authors noted, nicotinamide appears most effective when initiated after the first diagnosis of skin cancer and may be especially valuable in lowering cutaneous squamous cell carcinoma risk among select patients. “The results of this cohort study suggest that there is a decreased risk of skin cancer among patients treated with nicotinamide, with the greatest effect seen when initiated after the first skin cancer,” they concluded.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
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