Vitamin d levels in subjects with prostate cancer compared to age-matched controls

The double disparity: Vitamin D deficiency and lethal prostate cancer in black men

Epidemiological data from as early as the 1930s documented a dramatic racial disparity in prostate cancer incidence, survival, and mortality rates among Black men-a trend that persists to this day. Black men are disproportionately burdened by prostate cancer, developing the disease at younger ages, facing more aggressive and lethal forms, and ultimately experiencing double the mortality rate of men of European descent. Investigating the multifactorial contributors to this racial disparity has been extensive, but results have often been inconsistent or inconclusive, making it difficult to pinpoint clear correlations. However, there is strong evidence suggesting that vitamin D deficiency is significantly associated with lethal forms of prostate cancer. This is particularly important given that Black men are at a higher risk for both vitamin D deficiency and developing aggressive, lethal prostate cancer, presenting a double disparity. The disparity in prostate cancer and vitamin D extends to Black men outside the US, but most of the studies have been done in African American men. Understanding the available evidence on vitamin D deficiency and its influence on prostate cancer biology may reveal new opportunities for prevention and therapeutic intervention.

Association between vitamin D deficiency and prostate cancer: Prospective case-control study

Objective:

We aimed to find out the association of low serum vitamin D levels with the incidence of prostate cancer through a prospective case-control study.

Material and methods:

This study was carried out in the tertiary care hospital (India). All newly diagnosed patients of prostate cancer and age-matched controls were included. Serum vitamin D levels were measured in all of them. Vitamin D status (ng/mL) was classified as severe deficiency <10, moderate deficiency 10–<30, normal 30–100, and toxicity >100. Normality of the data was tested by the Kolmogorov–Smirnov test, statistical analysis was done with Statistical Package for the Social Sciences version 26.0, p-value of <0.05 was considered significant.

Results:

In our study, 320 cases and 320 controls were included. The mean vitamin D levels in cases and controls were 15.71 ± 6.5 (ng/mL) and 17.63 ± 4.54 (ng/mL), respectively, ( p-Value <0.01). Patients with severe vitamin D deficiency (73.58%) had a Gleason score ⩾8 on biopsy and 79.24% of them had a serum prostate specific antigen (PSA) level >20 ng/mL.

Conclusion:

We had concluded that there was no significant association between vitamin D deficiency and increased risk of prostate cancer, although patients with higher-grade prostate cancer and with higher PSA level had severe vitamin D deficiency.

Level of evidence:

Not applicable for this multicentre audit.

How competing risks affect the epidemiological relationship between vitamin D and prostate cancer incidence? A population-based study

We hypothesized that controversial results regarding the epidemiological relationship between circulating 25-hydroxyvitamin D, 25(OH)D, and risk of prostate cancer (PCA) incidence are partly due to competing risks. To test the hypothesis, we studied associations across 25(OH)D, PCA and death in 2578 middle-aged men belonging to the Kuopio Ischaemic Heart Disease Risk Factor Study. The men were free of cancer at baseline, and the mean (SD) follow-up time was 23.3 (9.1) years. During this period, 296 men had a PCA diagnosis, and 1448 men died without the PCA diagnosis. The absolute risk of developing PCA was highest in the highest 25(OH)D tertile (15%), whereas that of death was highest in the lowest 25(OH)D tertile (67%). A competing risk analysis showed that belonging to the highest 25(OH)D tertile increased the risk of PCA incidence and improved survival with the respective hazard ratios (HR) of 1.35 (95% CI = 1.07-1.70) and 0.79 (95% CI = 0.71-0.89). Adjusting for 10 covariates together with 25(OH)D did not significantly change the results, but the respective adjusted HRs for PCA and death were 1.20 and 0.87. To conclude, the competing risk analysis did not eliminate the direct relationship between 25(OH)D and PCA but rather strengthened it.

Circulating Vitamin D and Selenium Levels and Outcome in Prostate Cancer Patients: Lessons from the MARTINI-Lifestyle Cohort

BACKGROUND

Dietary agents, in particular vitamin D (Vit D) and selenium, are widely used by prostate cancer (PCa) patients to improve cancer outcomes.

OBJECTIVE

To investigate whether plasma Vit D and selenium levels prior to radical prostatectomy (RP) are associated with worse pathologic tumor characteristics and increased risk of disease recurrence.

DESIGN, SETTING, AND PARTICIPANTS

A total of 3849 men with PCa scheduled for RP in the Martini-Klinik at the University Hospital Hamburg-Eppendorf, Hamburg, Germany, between January 2014 and December 2018 were included in this study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age, and clinical and laboratory values were collected prior to RP. Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) ≥0.2 μg/l and rising after RP. Kaplan-Meier plots depicted BCR-free survival. Cox regression models (adjusted for age, preoperative PSA, pT stage, pN stage, pGG, surgical margin status, and year of surgery) tested the relationship between oncologic outcomes and Vit D and selenium levels.

RESULTS AND LIMITATIONS

Median plasma Vit D and selenium levels were 19.3 and 71 μg/l, respectively. Circulating Vit D and selenium levels correlated inversely with PSA values. Histologic grade, pT stage, and pN stage were not associated with Vit D and selenium levels at the time of RP. In the overall cohort, BCR-free survival at 3 yr of follow-up was 82.9%. When stratified according to median Vit D levels, BCR-free survival at 3 yr of follow-up was 82.7% and 83.0% (p ≤ 0.59). Upon stratification according to median selenium levels, BCR-free survival was 82.2% and 83.7% (p = 0.19). In a multivariable Cox regression model predicting BCR, lower Vit D and selenium levels were not independent predictors of BCR.

CONCLUSIONS

Plasma Vit D and selenium levels prior to RP were not associated with BCR-free survival.

PATIENT SUMMARY

The results of the MARTINI-Lifestyle cohort could not show a correlation between the occurrence of biochemical recurrence of prostate cancer after radical prostatectomy and the serum levels of vitamin D and selenium. A recommendation should therefore be made to compensate for a potential deficiency and not with the expectation of a reduction in the risk of progression.

Vitamin D-Induced Molecular Mechanisms to Potentiate Cancer Therapy and to Reverse Drug-Resistance in Cancer Cells

Increasing interest in studying the role of vitamin D in cancer has been provided by the scientific literature during the last years, although mixed results have been reported. Vitamin D deficiency has been largely associated with various types of solid and non-solid human cancers, and the almost ubiquitous expression of vitamin D receptor (VDR) has always led to suppose a crucial role of vitamin D in cancer. However, the association between vitamin D levels and the risk of solid cancers, such as colorectal, prostate and breast cancer, shows several conflicting results that raise questions about the use of vitamin D supplements in cancer patients. Moreover, studies on vitamin D supplementation do not always show improvements in tumor progression and mortality risk, particularly for prostate and breast cancer. Conversely, several molecular studies are in agreement about the role of vitamin D in inhibiting tumor cell proliferation, growth and invasiveness, cell cycle arrest and inflammatory signaling, through which vitamin D may also regulate cancer microenvironment through the activation of different molecular pathways. More recently, a role in the regulation of cancer stem cells proliferation and short non-coding microRNA (miRNAs) expression has emerged, conferring to vitamin D a more crucial role in cancer development and progression. Interestingly, it has been shown that vitamin D is able not only to potentiate the effects of traditional cancer therapy but can even contribute to overcome the molecular mechanisms of drug resistance—often triggering tumor-spreading. At this regard, vitamin D can act at various levels through the regulation of growth of cancer stem cells and the epithelial–mesenchymal transition (EMT), as well as through the modulation of miRNA gene expression. The current review reconsiders epidemiological and molecular literature concerning the role of vitamin D in cancer risk and tumor development and progression, as well as the action of vitamin D supplementation in potentiating the effects of drug therapy and overcoming the mechanisms of resistance often triggered during cancer therapies, by critically addressing strengths and weaknesses of available data from 2010 to 2020.

Systematic review and meta-analysis of the associations between body mass index, prostate cancer, advanced prostate cancer, and prostate-specific antigen

PURPOSE

The relationship between body mass index (BMI) and prostate cancer remains unclear. However, there is an inverse association between BMI and prostate-specific antigen (PSA), used for prostate cancer screening. We conducted this review to estimate the associations between BMI and (1) prostate cancer, (2) advanced prostate cancer, and (3) PSA.

METHODS

We searched PubMed and Embase for studies until 02 October 2017 and obtained individual participant data from four studies. In total, 78 studies were identified for the association between BMI and prostate cancer, 21 for BMI and advanced prostate cancer, and 35 for BMI and PSA. We performed random-effects meta-analysis of linear associations of log-PSA and prostate cancer with BMI and, to examine potential non-linearity, of associations between categories of BMI and each outcome.

RESULTS

In the meta-analyses with continuous BMI, a 5 kg/m2 increase in BMI was associated with a percentage change in PSA of - 5.88% (95% CI - 6.87 to - 4.87). Using BMI categories, compared to normal weight men the PSA levels of overweight men were 3.43% lower (95% CI - 5.57 to - 1.23), and obese men were 12.9% lower (95% CI - 15.2 to - 10.7). Prostate cancer and advanced prostate cancer analyses showed little or no evidence associations.

CONCLUSION

There is little or no evidence of an association between BMI and risk of prostate cancer or advanced prostate cancer, and strong evidence of an inverse and non-linear association between BMI and PSA. The association between BMI and prostate cancer is likely biased if missed diagnoses are not considered.

Circulating vitamin D concentration and risk of prostate cancer: a dose-response meta-analysis of prospective studies

Background

Though many studies have been performed to elucidate the association between circulating vitamin D and prostate cancer, no conclusive result is available. We carried out a dose-response meta-analysis to quantitatively examine the association of circulating 25-hydroxyvitamin D (25[OH]D) concentration with prostate cancer.

Methods

Only prospective studies examining the associations of circulating 25[OH]D concentration with prostate cancer were eligible for the meta-analysis. A random-effect meta-analysis was done first, to calculate the summary relative risk (RR) and 95% confidence intervals (CIs) comparing the higher concentration with the lower concentration of 25[OH]D. A dose-response meta-analysis using random-effects model was then carried out to evaluate the nonlinearity and calculate the summary RR caused per 10 ng/mL increment.

Results

Nineteen prospective cohort or nested case-control studies were included. Higher 25[OH]D concentration was significantly correlated with elevated risk of prostate cancer (RR =1.15, 95% CI 1.06-1.24). No nonlinear relationship was found between 25[OH]D concentration and risk of prostate cancer (P=0.654). Dose-response meta-analysis showed that the summary RR caused per 10 ng/mL increment in circulating 25[OH]D concentration was 1.04 (95% CI 1.02-1.06). Subgroup analysis also found a modest dose-response relationship. Funnel plot and Egger's test did not detect publication bias.

Conclusion

The findings suggest that highest 25[OH]D concentration is correlated with elevated risk of prostate cancer and a modest dose-response effect exists in this association; however, more studies are needed.

Risk of prostate cancer in African-American men: Evidence of mixed effects of dietary quercetin by serum vitamin D status

BACKGROUND

African-American (AA) men experience higher rates of prostate cancer (PCa) and vitamin D (vitD) deficiency than white men. VitD is promoted for PCa prevention, but there is conflicting data on the association between vitD and PCa. We examined the association between serum vitD and dietary quercetin and their interaction with PCa risk in AA men.

METHODS

Participants included 90 AA men with PCa undergoing treatment at Howard University Hospital (HUH) and 62 controls participating in HUH's free PCa screening program. We measured serum 25-hydroxy vitD [25(OH)D] and used the 98.2 item Block Brief 2000 Food Frequency Questionnaires to measure dietary intake of quercetin and other nutrients. Case and control groups were compared using a two-sample t-test for continuous risk factors and a Fisher exact test for categorical factors. Associations between risk factors and PCa risk were examined via age-adjusted logistic regression models.

RESULTS

Interaction effects of dietary quercetin and serum vitD on PCa status were observed. AA men (age 40-70) with normal levels of serum vitD (>30 ng/ml) had a 71% lower risk of PCa compared to AA men with vitD deficiency (OR = 0.29, 95%CI: 0.08-1.03; P = 0.055). In individuals with vitD deficiency, increased dietary quercetin showed a tendency toward lower risk of PCa (OR = 0.91, 95%CI: 0.82-1.00; P = 0.054, age-adjusted) while men with normal vitD were at elevated risk (OR = 1.23, 95%CI: 1.04-1.45).

CONCLUSION

These findings suggest that AA men who are at a higher risk of PCa may benefit more from vitD intake, and supplementation with dietary quercetin may increase the risk of PCa in AA men with normal vitD levels. Further studies with larger populations are needed to better understand the impact of the interaction between sera vitD levels and supplementation with quercetin on PCa in AA men.