Prediagnostic Plasma Vitamin D Metabolites and Mortality among Patients with Prostate Cancer

Laboratory evidence suggests that vitamin D might influence prostate cancer prognosis.We examined the associations between prediagnostic plasma levels of 25(OH)vitamin D [25(OH)D] and 1,25(OH)(2) vitamin D [1,25(OH)(2)D] and mortality among 1822 participants of the Health Professionals Follow-up Study and Physicians' Health Study who were diagnosed with prostate cancer. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total mortality (n = 595) and lethal prostate cancer (death from prostate cancer or development of bone metastases; n = 202). In models adjusted for age at diagnosis, BMI, physical activity, and smoking, we observed a HR of 1.22 (95% CI: 0.97, 1.54) for total mortality, comparing men in the lowest to the highest quartile of 25(OH)D. There was no association between 1,25(OH)(2)D and total mortality. Men with the lowest 25(OH)D quartile were more likely to die of their cancer (HR: 1.59; 95% CI: 1.06, 2.39) compared to those in the highest quartile (P(trend) = 0.006). This association was largely explained by the association between low 25(OH)D levels and advanced cancer stage and higher Gleason score, suggesting that these variables may mediate the influence of 25(OH)D on prognosis. The association also tended to be stronger among patients with samples collected within five years of cancer diagnosis. 1,25(OH)(2)D levels were not associated with lethal prostate cancer.Although potential bias of less advanced disease due to more screening activity among men with high 25(OH)D levels cannot be ruled out, higher prediagnostic plasma 25(OH)D might be associated with improved prostate cancer prognosis

Consumption of Fish Products across the Lifespan and Prostate Cancer Risk

Objective: To examine whether fish and fish oil consumption across the lifespan is associated with a lower risk of prostate cancer. Design: The study was nested among 2268 men aged 67–96 years in the AGES-Reykjavik cohort study. In 2002 to 2006, dietary habits were assessed, for early life, midlife and later life using a validated food frequency questionnaire. Participants were followed for prostate cancer diagnosis and mortality through 2009 via linkage to nationwide cancer- and mortality registers. Adjusting for potential confounders, we used regression models to estimate odds ratios (ORs) and hazard ratios (HRs) for prostate cancer according to fish and fish oil consumption. Results: Among the 2268 men, we ascertained 214 prevalent and 133 incident prostate cancer cases, of which 63 had advanced disease. High fish consumption in early- and midlife was not associated with overall or advanced prostate cancer. High intake of salted or smoked fish was associated with a 2-fold increased risk of advanced prostate cancer both in early life (95% CI: 1.08, 3.62) and in later life (95% CI: 1.04, 5.00). Men consuming fish oil in later life had a lower risk of advanced prostate cancer [HR (95%CI): 0.43 (0.19, 0.95)], no association was found for early life or midlife consumption. Conclusions: Salted or smoked fish may increase risk of advanced prostate cancer, whereas fish oil consumption may be protective against progression of prostate cancer in elderly men. In a setting with very high fish consumption, no association was found between overall fish consumption in early or midlife and prostate cancer risk

Hazards ratios (HRs) and 95% confidence intervals (CIs) for total mortality and lethal prostate cancer among prostate cancer patients by quartiles of vitamin D metabolites, combining HPFS and PHS (N = 1822).

1<p>Crude mortality rate.</p>2<p>HR1: adjusted for age at diagnosis, body mass index, physical activity, and smoking; HR2: adjusted for age at diagnosis, body mass index, physical activity, smoking, and Gleason score; HR3: adjusted for age at diagnosis, body mass index, physical activity, smoking, Gleason score, and TNM stage; 25(OH)D and 1,25(OH)₂D were mutually adjusted.</p

Baseline Characteristics of 1822 men with prostate cancer according to Quartiles of Plasma 25(OH)D and 1,25(OH)₂D, HPFS (1993) and PHS (1982).

1<p>ANOVA test.</p>2<p>Chi-square test. Individuals with missing values were excluded from test.</p