PDQ (Physician Data Query)

PDQ (Physician Data Query) is the National Cancer Institute’s source of comprehensive cancer information. It contains peer-reviewed, evidence-based cancer information summaries on treatment, supportive care, screening, prevention, genetics, and complementary and alternative medicine. The summaries are regularly updated by six editorial boards. The following PDQ summaries were recently updated:

Surjana D, Halliday GM, Martin AJ, et al.: Oral nicotinamide reduces actinic keratoses in phase II double-blinded randomized controlled trials. J Invest Dermatol 132 (5): 1497–500, 2012. PMID 22297641

Chen AC, Martin AJ, Choy B, et al.: A Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer Chemoprevention. N Engl J Med 373 (17): 1618–26, 2015. PMID 26488693

The PDQ Skin Cancer Prevention summary was recently updated with information about a new chemopreventive agent, nicotinamide. Nicotinamide (vitamin B3) has been hypothesized to prevent nonmelanoma skin cancer (NMSC) by counteracting the cancer promoting effects of ultraviolet radiation on immune suppression and DNA damage. Support for the hypothesis that nicotinamide could be clinically useful in preventing the recurrence of actinic keratoses was provided by two 4-month clinical trials, with reduction in the number of new actinic keratoses as the primary outcome. Data from the trials indicated that nicotinamide was associated with a significantly lower number of average new lesions in patients with four or fewer actinic lesions at baseline.

The Oral Nicotinamide to Reduce Actinic Cancer (ONTRAC) trial was a phase III trial carried out in Sydney, Australia, that tested whether an oral dose of 500mg nicotinamide twice per day for 12 months would reduce the risk of new NMSCs in patients with at least two NMSC lesions who had been diagnosed within the previous 5 years. A total of 386 patients were randomly assigned to receive either nicotinamide or a placebo; randomization was stratified by study site, sex, and the number of NMSC lesions (more than six vs. six or fewer within the previous 5 years). At the end of the 12-months intervention, the rate of new NMSCs was 23% lower in the nicotinamide group than in the placebo group ( P = .02); the results were similar for both major histologic types of NMSC, basal cell carcinoma and squamous cell carcinoma. However, the true clinical significance of the ONTRAC results is difficult to discern because the results were presented using the number of lesions as the outcome, but no data were presented to indicate whether the number of patients with recurrent NMSCs was reduced in the nicotinamide group compared with that in the placebo group. Another caveat was that higher NMSC incidence rates were observed in the nicotinamide group at the 6-month post-intervention follow-up, when one would expect to see a continuation of the benefit of a chemopreventive agent.

In summary, the current evidence indicates that nicotinamide holds promise as a chemopreventive agent, but issues in the quality and quantity of relevant data result in a current evidence rating of “inadequate.” To review the summary, please use the following link:

http://www.cancer.gov/types/skin/hp/skin-prevention-pdq#link/_122_toc

The Stage IV Prostate Cancer Treatment section of the PDQ Prostate Cancer Treatment summary was recently updated to state that the addition of chemotherapy has been shown in randomized trials to improve overall survival compared with hormonal therapy alone. Text was added to state that, in one trial, 790 patients with metastatic, hormone-sensitive disease were randomly assigned to receive ADT with or without docetaxel. Follow-up data were provided (cited Sweeney et al. and level of evidence 1iiA). To review the summary, please use the following link:

http://www.cancer.gov/types/prostate/hp/prostate-treatment-pdq#link/_2394

The PDQ Supportive and Palliative Care Board recently completed a comprehensive review of the Pruritus summary. The Board conducted a review of the published literature and revised the text and title of the summary and updated the citations. To review the summary, please use the following link:

http://www.cancer.gov/about-cancer/treatment/side-effects/skin-nail-changes/pruritus-hp-pdq#section/all .