Baseline comorbidities in a skin cancer prevention trial in Bangladesh

Abstract

Background Epidemiologic research suggests that increased cancer risk due to chronic arsenic exposure persists for several decades even after the exposure has terminated. Observational studies suggest antioxidants exert a protective effect on arsenical skin lesions and cancers among those chronically exposed to arsenic through drinking water. This study reports on the design, methods, and baseline analyses from the Bangladesh Vitamin E and Selenium Trial (BEST), a population based chemoprevention study conducted among adults in Bangladesh with visible arsenic toxicity. Materials and methods BEST is a 2×2 full factorial double-blind randomized controlled trial of 7,000 adults having manifest arsenical skin lesions evaluating the efficacy of 6-year supplementation with alpha-tocopherol (100 mg daily) and L-selenomethionine (200 μg daily) for the prevention of non-melanoma skin cancer. Results In cross-sectional analyses, we observed significant associations of skin lesion severity with male sex (female prevalence odds ratio (POR)=0.87; 95% CI=0.79–0.96), older age (aged 36–45 POR=1.27; 95% CI=1.13–1.42; aged 46–55 POR=1.44; 95% CI=1.27–1.64; and aged 56–65 POR=1.50; 95% CI=1.26–1.78 compared to aged 25–35), hypertension (POR=1.29; 95% CI=1.08–1.55), diabetes (POR=2.13; 95% CI=1.32–3.46), asthma (POR=1.55; 95% CI=1.03–2.32), and peptic ulcer disease (POR=1.20; 95% CI=1.07–1.35). Conclusions We report novel associations between arsenical skin lesions with several common chronic diseases. With the rapidly increasing burden of preventable cancers in developing countries, efficient and feasible chemoprevention study designs and approaches, such as employed in BEST, may prove both timely and potentially beneficial in conceiving cancer chemoprevention trials in Bangladesh and beyond.

Arsenic exposure, telomere length, and expression of telomere-related genes among Bangladeshi individuals

“…BEST participants(n=7,000) are adult residents in Araihazar, Matlab, and surrounding areas in Bangladesh with prevalent arsenic-related skin lesions (Argos et al, 2013). For all participants, biological samples were collected at the time of the baseline interview prior to dietary supplementation, including urine samples for arsenic measurement and mononuclear cells for RNA isolation.…”

Chemoprevention of Keratinocyte Carcinomas: An Updated Review

“…Argos et al are currently testing the chemoprotective role of 100 mg of a-tocopherol with 200 lg of L-selenomethionine daily in a 6-year trial. No results of this on-going trial have been published to date [42]. The effect of vitamin E on KC prevention has yet to be confirmed.…”

Genome-wide association study of smoking behaviours among Bangladeshi adults

“…Trained study physicians, blinded to participants’ exposure to arsenic, conducted in-person interviews and clinical evaluations, and collected urine and blood samples from participants in their homes using structured protocols. BEST is a 2×2 factorial randomised chemoprevention trial evaluating the long-term effects of vitamin E and selenium supplementation on non-melanoma skin cancer risk 16. BEST participants are residents of Araihazar (the same geographic area as HEALS participants), Matlab and surrounding areas.…”