Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hypothesis that vitamin D deficiency increases the risk of clinical prostate cancer has stimulated an extensive body of research. Ecologic studies have shown that mortality rates from prostate cancer are inversely correlated with levels of ultraviolet radiation, the principal source of vitamin D. Human prostate cells express receptors for 1,25-Dihydroxyvitamin D which exerts pleitropic anticancer effects on these cells in vitro and in animal models. Moreover, normal prostate cells synthesize 1,25-Dihydroxyvitamin D from circulating levels of 25-OHD, whose levels are dependent on exposure to ultraviolet light. Analytic epidemiologic studies of vitamin D and prostate cancer have focused on polymorphisms in the vitamin D receptor (VDR), on serum vitamin D levels, and on solar exposure. A role for VDR polymorphisms in prostate cancer risk and progression is established. Prospective studies of serum 25(OH)D do not support a protective role for higher levels of 25(OH)D on prostate cancer risk overall, but a role for vitamin D deficiency is supported by several studies. Conversely, a growing body of evidence implicates low levels of 25-OHD with an increased risk of fatal prostate cancer. The results of most epidemiologic studies of sunlight exposure are consistent with a protective effect of exposure to ultraviolet radiation. The discrepancy between the results of studies of solar exposure and studies of serum 25-OHD may be related to methodological differences and to uncertainties regarding the critical period for vitamin D exposure. Additionally, both high dietary intake of calcium and high levels of calcium in serum are positively associated with prostate cancer risk. The relationship between serum 25(OH)D levels and risk of prostate cancer may differ by calcium intake.
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PMID:Vitamin D, sunlight, and the epidemiology of prostate cancer. 2309 20

Cancer mortality rates vary inversely with geographic latitude and solar ultraviolet-B doses. This relationship may be due to an inhibitory role of vitamin D on cancer development. The relationship between vitamin D and cancer appears to be stronger for studies of cancer mortality than incidence. Because cancer mortality reflects both cancer incidence and survival, the difference may be due to effects of vitamin D on cancer survival. Here we review analytic epidemiologic studies investigating the relation between vitamin D, measured by circulating levels of 25-hydroxyvitamin D (25-OHD), and cancer survival. A relationship between low 25-OHD levels and poor survival is shown by most of the reviewed studies. This relationship is likely to be causal when viewed in light of most criteria for assessing causality (temporality, strength, exposure-response, biological plausibility and consistency). A serum level of 25-OHD around 50 nmol/L appears to be a threshold level. Conversely, there are several mechanisms whereby cancer could lower serum levels of 25-OHD. The severity of disease at the time of diagnosis and time of serum sampling are key factors to clarify the temporal aspect of these relationships. Evidence that vitamin D supplementation could retard the disease process or prolong survival time would be key evidence, but is difficult to generate. However, recent clinical trial results in prostate cancer support a role for vitamin D in this regard.
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PMID:The Inverse Relationship between 25-Hydroxyvitamin D and Cancer Survival: Discussion of Causation. 2420 53

The effects of blood levels of 25-hydroxyvitamin D (25-OHD) on the risk of total, low-, and high-grade prostate cancer were examined in the Selenium and Vitamin E Cancer Prevention Trial (SELECT) and the Prostate Cancer Prevention Trial (PCPT). In the SELECT study, plasma 25-OHD levels were associated with a linear decrease in prostate cancer risk for high-grade cancers in African American men and an apparent "U"-shaped effect in other men. The "U-shaped" curve may reflect detection bias. In the PCPT study, in which detection bias was minimized, serum 25-OHD levels were associated with a linear decrease in the risk of high-grade prostate cancers. The results from these large prevention trials support the hypothesis that circulating levels of 25-OHD decrease the risk of clinically relevant prostate cancers.
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PMID:Vitamin D in blood and risk of prostate cancer: lessons from the Selenium and Vitamin E Cancer Prevention Trial and the Prostate Cancer Prevention Trial. 2508 35