Serum 25(OH)-vitamin D concentration and risk of esophageal squamous dysplasia

Vitamin D in esophageal cancer: Is there a role for chemoprevention?

Vitamin D has emerged as a promising anti-cancer agent due to its diverse biological effects on tumor differentiation, apoptosis and suppression of cellular proliferation. Current evidence suggests a protective role of vitamin D in colon cancer. The effect of vitamin D on esophageal cancer remains controversial. Multiple studies investigated the association between vitamin D and esophageal cancer, employing different modes of assessment of vitamin D status such as serum 25-hydroxyvitamin D levels, vitamin D dietary intake or exposure to ultraviolet B (UVB) radiation. Genetic variations of the vitamin D receptor (VDR) gene and VDR expression in esophageal specimens have also been investigated. Ecological studies evaluating exposure to UVB radiation yielded an inverse correlation with esophageal cancer. When vitamin D dietary intake was assessed, direct association with esophageal cancer was observed. However, circulating 25-hydroxyvitamin D concentrations showed inconsistent results. In this review article, we present a detailed summary of the current data on the effects of vitamin D on various histological subtypes of esophageal cancer and their precursor lesions. Well-powered prospective studies with accurate measurement of vitamin D status are needed before chemoprevention with vitamin D is recommended, as current evidence does not support a chemopreventive role of vitamin D against esophageal cancer. Future studies looking at the incidence of esophageal cancer in patients with pre-cancerous lesions (Barrett's esophagus and squamous cell dysplasia) receiving vitamin D supplementation are needed.

Associations between adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations and biomarkers of inflammation, hormonal, and insulin response

Adherence to the 2007 WCRF/AICR cancer prevention recommendations has been associated with lower cancer risk but the underlying biological mechanisms have not been elucidated. We utilized dietary and lifestyle data from 11,342 women in the Nurses' Health Study and 8,136 men in the Health Professionals Follow-up Study, to investigate associations between adherence scores and markers of inflammation, hormonal and insulin response. Two scores ranging from 0 to 3 were constructed to assess adherence to the energy balance-related recommendations (weight management, physical activity, energy density); and the plant, animal foods and alcohol intake recommendations; with higher scores indicating greater adherence. The following biomarkers were assessed in plasma samples donated by chronic disease-free women (1990) and men (1994): C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α receptor 2 (TNFαR2) and adiponectin for inflammation; estrone and estradiol for hormonal response in women, C-peptide for hyperinsulinemia; and triglycerides/high density lipoprotein-cholesterol (TG/HDL) ratio for insulin resistance. In multivariable-adjusted linear regression analyses, we estimated relative concentrations of biomarkers across adherence categories. There was a significant trend of lower (higher for adiponectin) biomarker concentrations with higher adherence to the energy balance recommendations (all p trend <0.0001). Comparing the highest (3) to the lowest recommendation category (0-1), the percent difference in relative concentrations of biomarkers was CRP, -69%; IL6, -41%; TNFαR2, -13%; adiponectin, +36%; C-peptide, -43%; TG/HDL, -43%; estrone, -31%; and estradiol, -43%; in women; and CRP, -59%; IL6, -42%; TNFαR2, -10%; adiponectin, +22%; C-peptide, -44%; and TG/HDL, -40%; in men. In contrast, associations between adherence to the plant, animal foods and alcohol intake recommendations and biomarker concentrations were weaker, and mostly nonsignificant. The healthier biomarker profile associated with greater adherence to the WCRF/AICR cancer prevention recommendations is driven mainly by adherence to the energy balance-related recommendations.