Alison Mondul

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NCI

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PLCO (Learn more about this study)

2010-0178

Sep 23, 2010

Serum Vitamin D and Risk of Bladder Cancer

In the past several years, there has been growing interest in the role of vitamin D in disease prevention. Data suggest that media attention on the role of vitamin D in various diseases has led to a dramatic increase in the use of vitamin D supplements in the US. Despite the uptake of supplement use by the public, the influence of vitamin D on cancer remains unclear. Vitamin D is thought to protect against cancer at many sites, however, to our knowledge, the only study to date on the association between serum 25(OH)D and risk of bladder cancer was the study we conducted within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a large primary cancer prevention trial of (alpha)-tocopherol and (beta)-carotene supplementation among Caucasian male smokers from southwestern Finland. After multivariable adjustment, we found that men lower 25-hydroxyvitamin D (25(OH)D) had an approximately 2-fold statistically significantly increased risk of bladder cancer. These findings are exciting, but require replication and several questions remain unanswered including the generalizability to women and non-smokers. Further, because the distribution of vitamin D levels in the ATBC Study participants is rather low because the latitude in Finland is quite high. In our previous study we were unable to examine men with very high (e.g. 75 - 100 or greater than or equal to100 nmol/L) 25(OH)D levels separately. We propose to examine the association between 25(OH)D and risk of bladder cancer in the PLCO cohort, a population that includes women and non-smokers, and which has a higher distribution of 25 (OH) D concentrations than the ATBC Study. Because it is an important health concern, understanding the influence of vitamin D on the risk of bladder cancer would provide a meaningful contribution to the debate over whether vitamin D supplements are, on balance, beneficial or harmful to the public's health.