The roles of ultraviolet-B irradiance, vitamin D, apolipoprotein E ε4, and diet in the risk of prostate cancer

Abstract

There have been a number of papers investigating the riskmodifying factors for prostate cancer, with diet, ultraviolet-B (UVB), and genetics among the leading factors considered, but there is still no agreement on the relative contribution of these factors. For example, the paper by Barnett et al. [1] found no link in their recent study between prediagnostic serum 25-hydroxyvitamin D [25(OH)D] and prostate cancer incidence in older men during a mean 5.3-year followup period [1]. This finding agrees with those of other recent reviews [2][3][4]. However, studies looking at prostate cancer incidence with respect to personal UVB irradiance ([5] and Refs. 31-33 in [1]) offer some of the more convincing evidence for a role of UVB and vitamin D in reducing the risk of prostate cancer. These studies were based on earlylife and/or long-term UVB irradiance, and prostate cancer is a type of cancer that progresses very slowly. There is also good evidence that vitamin D improves survival for those diagnosed with prostate cancer (Refs. 34 and 35 in [1]). Thus, vitamin D appears to be important in reducing the risk of prostate cancer over many years, so measuring 25(OH)D levels shortly before diagnosis of prostate cancer may not provide an accurate indication of the overall effect of vitamin D on prostate cancer risk.Although ecological studies have reported inverse correlations between solar UVB and prostate cancer incidence and/or mortality rates (Refs. 2, 28-30 in [1]), UVB may not be the only factor affecting the geographic variations. An inspection of the prostate cancer mortality rate maps in the Atlas of Cancer Mortality Rates in the United States, 1950States, -1994 indicates that the mortality rates are dissimilar from those of well-known vitamin D-sensitive cancers such as breast and colorectal cancer [4]. The highest rates for prostate cancer are in the northwest and the lowest are in the southeast, whereas the highest rates for breast and colorectal cancer are in the northeast and the lowest are in the southwest. Analysis of the map of greatest ancestry by county in the United States [7] found high correlations for many of the high-resolution features in prostate cancer and ancestry maps. This finding suggested that ethnic background played an important role in prostate cancer risk, which could be due to a combination of dietary and genetic factors. This finding formed the basis for a multicountry ecological study in which the apolipoprotein E e4 (ApoE4) allele and per capita gross domestic product correlated directly with prostate cancer incidence and mortality rates, and fraction of energy derived from cereals/grains correlated inversely [8]. Although this result is currently a hypothesis, it also explains several findings of prostate cancer epidemiology. It explains why black Americans, with nearly twice the ApoE4 allele prevalence of white Americans, have about twice the rate of prostate cancer [6]. It supports the finding that cholesterol is often a risk factor for prostate cancer but not for any other cancer...

Cancer Risks in Vitiligo Patients: A Nationwide Population-Based Study in Taiwan

“…Although the association between prostate cancer and vitiligo has not been reported previously, some studies have suggested the roles of ultraviolet irradiance and vitamin D in the risk of prostate cancer. Several studies indicated that vitamin D metabolites have an antiproliferative and a pro-differentiating effect on prostate cancer cell lines and that vitamin D deficiency is associated with prostate cancer risk [ 37 , 38 ]. Meanwhile, vitamin D deficiency has been linked to the development of autoimmune disorders [ 39 , 40 ].…”

Vitamin D deficiency in minority populations

“…25(OH)D 3 has a reported half-life of 15 d ( 27 ) , and therefore decreases from summer (when solar radiation is highest) to winter ( 28 ) . Observational studies suggest higher cancer mortality rates for patients diagnosed in winter ( 29 , 30 ) , at northern latitudes ( 31 , 32 ) and in areas with less UV radiation from sunshine ( 33 , 34 ) , although genetics may contribute ( 35 ) . Additionally, previous research suggests that racial differences in the synthesis of vitamin D from sunshine are largest in January ( 36 ) .…”

Prostate Cancer: Current Treatment and Prevention Strategies

“…The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was designed on 35,533 healthy men from American and African-American origin by Dunn et al(53), and they observed that neither selenium nor vitamin E, alone or together, prevented prostate cancer in this heterogeneous population. However there are evidences that vitamin D improves the survival of patients with prostate cancer, and vitamin D appeared to be important in reducing the risk of prostate cancer over many years (54). A high vitamin B-6 intake has also been suggested to improve prostate cancer survival among men with a diagnosis of localized-stage disease (55).…”