Oral nicotinamide prevents non-melanoma skin cancer in high-risk patients

By Anne Harding

NEW YORK (Reuters Health) - Oral nicotinamide can prevent non-melanoma skin cancers (NMSCs) in high-risk individuals, according to phase 3 trial results presented at the American Society of Clinical Oncology meeting in Chicago.

Physicians should consider nicotinamide for people who have had at least two NMSCs in the past five years, Dr. Andrew James Martin told Reuters Health in a telephone interview.

Martin, a biostatistician with the National Health and Medical Research Council Clinical Trials Centre at the University of Sydney in Australia, presented the findings in a talk this past Saturday.

"We're suggesting that nicotinamide could be considered as something to add on to those routine strategies that must be maintained in people who have had a history of skin cancer and have an otherwise normally functioning immune system," including using sunscreen and avoiding sun exposure, he added.

Martin and his colleagues, including Dr. Diona Damian of Royal Prince Alfred Hospital in Camperdown, New South Wales, randomly assigned 386 immune-competent patients to receive 500 mg of nicotinamide twice a day or a placebo for 12 months.

Study participants had to have at least two confirmed NMSCs in the past five years, but on average they had about eight, Martin noted. Their average age was 66 (range, 30 to 91).

"These are folks that had really sun-damaged skin, they had a heavy track record of non-melanoma skin cancer," he added.

Patients underwent assessment for new NMSCs every three months. The average rate of NMSCs at one year, the study's primary endpoint, was 1.77 for patients on nicotinamide, versus 2.42 for patients on placebo, for an estimated relative rate reduction (RRR) of 0.23. Estimated RRR was 0.20 for basal cell carcinomas (p=0.1) and 0.30 for squamous cell carcinomas (p=0.05).

Patients in the treatment group also had fewer actinic keratoses at each assessment than patients on placebo. Adverse event rates were similar for the nicotinamide and placebo groups.

"We see some evidence within our trial that nicotinamide might be more effective for the half that were in the greatest risk category," Martin said. "There's a suggestion in our study that nicotinamide was more effective for the group that had higher numbers of skin cancers in the past."

He emphasized that nicotinamide should be considered in addition to sun protection and sunscreen use, and not as a replacement for these approaches, which remain essential for preventing NMSCs.

Animal studies have suggested that nicotinamide can help promote DNA damage repair in melanocytes, Martin noted. "It's a long way from the bench top to real life in people, but that is certainly a promising result, and we are in the process of designing and seeking funding for a trial of nicotinamide in a high risk melanoma patient group," he said.

"For patients with a high risk of squamous cell carcinoma of the skin or high risk basal cell carcinoma with multiple recurrences, I really see no downside to recommending this to patients at this point," Dr. Gary Schwartz, chief of the division of hematology and oncology at Columbia University School of Medicine and New York Presbyterian Hospital, told Reuters Health in a telephone interview. Schwartz did not take part in ONTRAC.

"The beauty is in its simplicity-a pill you take twice a day that's a vitamin with no side effects," he added. "It's so simple and has such a big impact."

Schwartz too emphasized that nicotinamide is not a replacement for sun protection, but an adjunct to it. "We cannot forget that the culprit of these skin cancers is the sun," he said. "The application of sunscreen is still a critical way to prevent all of these skin cancers."

SOURCE: http://bit.ly/1M5v8UM

Am Soc Clin Oncol 2015.

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