Low serum vitamin D may signal more aggressive prostate cancer




Serum 25-hydroxyviatmin D (25-OH D) deficiency was associated with greater risk for adverse pathology in men with localized prostate cancer undergoing radical prostatectomy, particularly among men with intermediate-risk disease.

Men with adverse pathology at radical prostatectomy had lower median serum 25-OH D (22.7 ng/mL; interquartile range [IQR], 15.9 to 29.0) compared with their counterparts (27.0 ng/mL; IQR, 20.0 to 34.0; P = .007), and they were more likely to have a serum 25-OH D level less than 30 ng/mL (80.5% v. 57.3%; P = .001) (J Clin Oncol. 2016 Feb. 22. doi: 10.1200/JCO.2015.65.1463).

Multiple logistic regression showed that serum 25-OH D level less than 30 ng/mL was associated with adverse pathology independent of age, serum PSA, and abnormal findings on digital rectal examination (odds ratio [OR], 2.51; 95% CI, 1.18 to 5.33; P = .02). Stratified analysis showed that in men with National Comprehensive Cancer Network intermediate prostate cancer at diagnosis, serum 25-OH D less than 30 ng/mL was significantly associated with adverse pathology (OR, 3.62; 95% CI, 1.15 to 11.46; P = .03).

The study cohort from Chicago demonstrated a disparity in vitamin D levels between black men and white men, which may contribute to differences by race observed in adverse pathology at radical prostatectomy.

“The initial assessment of our Chicago cohort demonstrated a significant disparity regarding low vitamin D levels and black race compared with white men in both univariate and multivariate analyses. In fact, greater than 90% of black men in that study had vitamin D levels less than 30 ng/mL,” wrote Dr Yaw Nyame of the Glickman Urological & Kidney Institute, Cleveland Clinic, and colleagues.

The cross-sectional, observational study from 2009 to 2014 included 190 men who underwent radical prostatectomy for localized prostate cancer. Adverse pathology was defined by the presence of dominant Gleason pattern 4, the presence of any pattern 5, and pathologic stage pT3aN0M0 or higher.

In total, 87 men (45.8%) had adverse pathology at radical prostatectomy. The median age of men with adverse pathology was 65.0 years, compared with 62.0 years for their counterparts (P = .005); median BMI was 28.9 kg/m2 vs. 27.7 kg/m2 (P = .04); and serum PSA was 6.8 ng/mL vs. 4.4 ng/mL (P less than .001). Men with adverse pathology at radical prostatectomy were more likely to self identify as black (P = .03).

Studies have shown that prostate cancer cells express the vitamin D receptor, and vitamin D has been shown to inhibit cellular proliferation, differentiation, and apoptosis.

Dr. Yaw Nyame reported having no disclosures. Several of his coauthors reported ties to industry.

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