Skin Cancer Prevention: are systemic Retinoids effective ? (Chemoprophylaxis)

• Take Home Message: There is a trend of the usefulness of retinoids in the prevention of non-melanoma skin cancers (NMSC, now called Keratinocyte Carcinoma). However the results are NOT statistically significant (see comments) (Study from the Philippines)

Comments

-Chemoprevention of skin cancer is usually done by administering oral acitretin (or other retinoids)

-It might be useful to do a study segregating isotretinoin and acitretin in 2 groups

-The study is a review of articles in the literature (see Abstract)

Abstract

-Background: Non-melanoma skin cancers (NMSC) are the most common malignancies in the human population. These consist of basal cell carcinomas (BCC) and squamous cell carcinoma (SCC). In patients with previous skin cancers, there is a ten-fold increase in incidence of developing subsequent NMSC. A chemopreventive agent may be useful in decreasing the incidence of NMSC and its sequelae. Systemic retinoids have shown promising results as chemopreventive agents in other high-risk populations, such as xeroderma pigmentosum and renal transplant patients. The objective of this study is to evaluate the safety and efficacy of systemic retinoids as chemopreventive agents in patients with previous history of NMSC.

–Methodology: The authors searched MEDLINE, Cochrane, Clinical trials, HERDIN database, and reference lists of trials and reviews for relevant studies. Two reviewers selected the studies for inclusion based on titles and abstracts, and assessed the methodological quality and risk of bias. Statistical analysis was done using the Review Manager 5 software.

–Result and Conclusion: We identified 4 trials (3,873 participants). All of the studies have moderate methodological quality. One study evaluated both 10mg isotretinoin and 25,000IU retinol compared with placebo. The interventions in the remaining studies were 10mg isotretinoin, 25,000IU retinol and 25mg acitretin. There is a trend favoring the utility of systemic retinoids in chemoprevention, but not statistically significant (RR = 0.94 [95% CI 0.89-1.00]). However, there are significantly more adverse events in the intervention group. Side effects may limit the use and utility of retinoids as chemopreventive agents, but risk and benefits should be assessed.

Reference: Regional Congress of Dermatology (RCD) 2016 – Singapore. RCD16-0321 Skin Cancers and Pre-cancers. RCD16-0150 Skin Cancers and Pre-cancers SYSTEMIC RETINOIDS IN PREVENTING SUBSEQUENT NON-MELANOMA SKIN CANCER (NMSC) IN PATIENTS WITH HISTORY OF NMSC: A SYSTEMATIC REVIEW AND META-ANALYSIS J.K. Gatmaitan1, F.M. Sumilang1, C. Ciriaco-Tan1,2,3 1University of the Philippines-Philippine General Hospital, Section of Dermatology, Manila, Philippines 2University of the East Ramon Magsaysay Medical Memorial Center, Department of Dermatology, Manila, Philippines 3St. Luke’s Medical Center, Department of Dermatology, Quezon City, Philippines