Low vitamin D increases risk for adverse pathology of localized prostate cancer

Vitamin D deficiency or insufficiency appeared associated with elevated risk for adverse pathology in men with localized prostate cancer who underwent radical prostatectomy, according to results of a cross-sectional, observational study.

Men with prostate cancer localized to the prostate gland — particularly those with low- or intermediate-risk disease — typically are managed with surveillance, which relies on risk stratification and diagnostic testing, researchers wrote.

Prior research has suggested an association between vitamin D deficiency and the risk for aggressive prostate cancer, but limited data exist about the relationship between vitamin D and pathologic findings at the time of radical prostatectomy.

Yaw A. Nyame, MD, MBA, urology resident at Cleveland Clinic, and colleagues evaluated 190 men who underwent radical prostatectomy for clinically localized prostate cancer within 1 year of positive prostate biopsy.

The researchers assessed the relationship between serum 25 hydroxyvitamin D (25-OH D) and adverse pathology at the time of radical prostatectomy.

Prior to treatment, about one-third (34.7%) of men met National Comprehensive Cancer Network (NCCN) criteria for low risk or very low risk disease; 68.4% presented with cT1c disease; 41.1% had a Gleason score of 3 + 3; and 83.2% had a PSA less than 10 ng/mL.

At the time of prostatectomy, 31.6% of men demonstrated extraprostatic disease — defined as pT3 — and 10% had seminal vesicle invasion.

Eighty-seven men (45.8%; median age, 65 years) in the cohort demonstrated adverse pathology at radical prostatectomy, and 103 men (54.2%; median age, 62 years) demonstrated nonadverse pathology.

Men with adverse pathology had significantly higher median BMI (28.9 vs. 27.7; P = .04) and serum PSA (6.8 ng/mL vs. 4.4 ng/mL; P < .001) than men without adverse pathology.

Univariate analysis showed men with adverse pathology at prostatectomy had lower median serum 25-OH D levels (22.7 ng/mL vs. 27 ng/mL; P = .007) and were more likely to have a serum 25-OH D level less than 30 ng/mL (80.5% vs. 57.3%, P = .001) compared with men without adverse pathology.

Multivariate analysis controlled for age, serum PSA and abnormal digital rectal examination revealed that a serum 25-OH D less than 30 ng/mL was associated with increased likelihood of adverse pathology (OR = 2.64, 95% CI, 1.25-5.59).

Results of stratified analysis revealed serum 25-OH D level (OR = 0.92; 95% CI, 0.86-0.98) and serum 25-OH D less than 30 ng/mL (OR = 3.62; 95% CI, 1.15-11.46) were significantly associated with adverse pathology among men with NCCN intermediate-risk prostate cancer at diagnosis.

“In a clinical setting, men with insufficient or deficient levels of 25-OH D at the time of prostate cancer diagnosis may benefit from supplementation, with a goal of increasing serum 25-OH D levels to a range of 30 to 55 ng/mL,” Nyame and colleagues wrote. “This could be achieved by assessing the serum vitamin D level at prostate cancer diagnosis in all men with clinically

localized disease prior to supplementation.”

The researchers acknowledged the study was limited by its cross-sectional design and the sample size, as well as the fact findings from men who underwent radical prostatectomy at large, tertiary medical institutions may not be generalizable to those treated in other settings.

They suggested a large randomized trial be conducted to evaluate the impact of long-term vitamin D supplementation in men with localized prostate cancer.

“Vitamin D could serve as an important biomarker of adverse pathology in men with prostate cancer, and the associations between prostate cancer aggressiveness and vitamin D deserve continued exploration,” Nyame and colleagues wrote. – by Kristie L. Kahl

Disclosure: Nyame reports no relevant financial disclosures. Please see the full study for a list of all other researchers’ relevant financial disclosures.