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Polychlorinated biphenyls (PCBs) are highly persistent environmental pollutants and are undesirable components of our daily food. PCBs are classified as human carcinogens, but the evidence for prostate cancer is limited and available data are inconsistent. We explored the link between non-dioxin-like PCB and grade of prostate cancer in a prospective cohort as well as in cell experiments. A population-based cohort of 32496 Swedish men aged 45-79 years was followed prospectively through 1998-2011, to assess the association between validated estimates of dietary PCB exposure and incidence of prostate cancer by grade (2789 cases, whereof 1276 low grade, 756 intermediate grade, 450 high grade) and prostate cancer mortality (357 fatal cases). In addition, we investigated a non-dioxin-like PCB153-induced cell invasion and related markers in normal prostate stem cells (WPE-stem) and in three different prostate cancer cell lines (PC3, DU145 and 22RV1) at exposure levels relevant to humans. After multivariable-adjustment, dietary PCB exposure was positively associated with high-grade prostate cancer, relative risk (RR) 1.35 [95% confidence interval (CI): 1.03-1.76] and with fatal prostate cancer, RR 1.43 (95% CI: 1.05-1.95), comparing the highest tertile with the lowest. We observed no association with low or intermediate grade of prostate cancer. Cell invasion and related markers, including MMP9, MMP2, Slug and Snail, were significantly increased in human prostate cancer cells as well as in prostate stem cells after exposure to PCB153. Our findings both from the observational and experimental studies suggest a role of non-dioxin-like PCB153 in the development of high-grade and fatal prostate cancer., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Zinc is involved in many essential cellular functions, including DNA repair and immune system maintenance. Although experimental evidence supports a role for zinc in prostate carcinogenesis, epidemiologic data are inconsistent; no data on cancer-specific survival have been reported., Objective: Our objective was to determine whether dietary zinc assessed near the time of prostate cancer diagnosis is associated with improved disease-specific survival., Design: This population-based cohort consists of 525 men aged <80 y from Örebro County, Sweden, with a diagnosis of prostate cancer made between 1989 and 1994. Study participants completed self-administered food-frequency questionnaires, and zinc intake was derived from nutrient databases. Cox proportional hazards regression was used to estimate multivariate hazard ratios (HRs) and 95% CIs for time to death from prostate cancer as well as death from all causes through February 2009 by quartile (Q) of dietary zinc intake. Models were also stratified by disease stage at diagnosis (localized or advanced)., Results: With a median follow-up of 6.4 y, 218 (42%) men died of prostate cancer and 257 (49%) died of other causes. High dietary zinc intake was associated with a reduced risk of prostate cancer-specific mortality (HR(Q4 vs Q1): 0.64; 95% CI: 0.44, 0.94; P for trend = 0.05) in the study population. The association was stronger in men with localized tumors (HR: 0.24; 95% CI: 0.09, 0.66; P for trend = 0.005). Zinc intake was not associated with mortality from other causes., Conclusion: These results suggest that high dietary intake of zinc is associated with lower prostate cancer-specific mortality after diagnosis, particularly in men with localized disease.

Background: Folate and other one-carbon metabolism nutrients may influence prostate cancer pathogenesis. Prior studies of these nutrients in relation to prostate cancer incidence have been inconclusive, and none have explored prostate cancer survival., Objective: The objective was to assess whether dietary intakes of folate, riboflavin, vitamin B-6, vitamin B-12, and methionine measured around the time of prostate cancer diagnosis are associated with prostate cancer survival., Design: This population-based prospective study comprised 525 men from Orebro, Sweden, who received a diagnosis of incident prostate cancer between 1989 and 1994 and completed a self-administered food-frequency questionnaire. Record linkages to the Swedish Death Registry enabled all cases to be followed for up to 20 y after diagnosis, and the cause of death was assigned via medical record review. Cox proportional hazards regression was used to calculate multivariable hazard ratios (HRs) and 95% CIs. During a median of 6.4 y of follow-up, 218 men (42%) died of prostate cancer and 257 (49%) of other causes., Results: A comparison of the highest with the lowest quartile showed that vitamin B-6 intake was inversely associated with prostate cancer-specific death (HR: 0.71; 95% CI: 0.46, 1.10; P for trend = 0.08), especially in men with a diagnosis of localized-stage disease (HR; 0.05; 95% CI: 0.01, 0.26; P for trend = 0.0003). However, vitamin B-6 intake was not associated with improved prostate cancer survival among advanced-stage cases (HR: 1.04; 95% CI: 0.64, 1.72; P for trend = 0.87). Folate, riboflavin, vitamin B-12, and methionine intakes were not associated with prostate cancer survival., Conclusion: A high vitamin B-6 intake may improve prostate cancer survival among men with a diagnosis of localized-stage disease.

Alkylresorcinols (AR), phenolic lipids exclusively present in the outer parts of wheat and rye grains, have been proposed as concentration biomarkers of whole-grain wheat and rye intake. A key feature of a good biomarker is high reproducibility, which indicates how accurately a single sample reflects the true mean biomarker concentration caused by a certain intake. In this study, the short- to medium-term reproducibility of plasma AR was determined using samples from a crossover intervention study, where men with prostate cancer (n = 17) were fed rye whole-grain/bran or refined wheat products for 6-wk periods. AR homologs C17:0 and C21:0 differed between the treatments (P < 0.001). The reproducibility determined by the intraclass correlation coefficient (ICC) was high (intervention period 1: ICC = 0.90 [95% CI = 0.82-0.98], intervention period 2: ICC = 0.88 [95% CI = 0.78-0.98]). The results show that a single fasting plasma sample could be used to estimate the mean plasma AR concentration during a 6-wk intervention period with constant intake at a precision of +/- 20% (80% CI). This suggests that the plasma AR concentration can be used as a reliable short- to medium-term biomarker for whole-grain wheat and rye under intervention conditions where intake is kept constant.

Background: Findings from epidemiologic studies of the effect of dairy foods (mainly milk) on the risk of bladder cancer have been inconsistent., Objective: We aimed to examine the association between the intake of cultured milk and other dairy foods and the incidence of bladder cancer in a prospective, population-based cohort., Design: We prospectively followed 82,002 Swedish women and men who were cancer-free and who completed a 96-item food-frequency questionnaire in 1997. Incident cases of bladder cancer were identified in the Swedish cancer registries., Results: During a mean follow-up of 9.4 y, 485 participants (76 women and 409 men) were diagnosed with bladder cancer. Total dairy intake was not significantly associated with risk of bladder cancer [> or =7.0 servings/d compared with < 3.5 servings/d: multivariate rate ratio (RR) = 0.87; 95% CI: 0.66, 1.15; P for trend = 0.33]. However, a statistically significant inverse association was observed for the intake of cultured milk (sour milk and yogurt). The multivariate RRs for the highest category of cultured milk intake (> or =2 servings/d) compared with the lowest category (0 serving/d) were 0.62 (95% CI: 0.46, 0.85; P for trend = 0.006) in women and men combined, 0.55 (95% CI: 0.25, 1.22; P for trend = 0.06) in women, and 0.64 (95% CI: 0.46, 0.89; P for trend = 0.03) in men. The intake of milk or cheese was not associated with bladder cancer risk., Conclusion: These findings suggest that a high intake of cultured milk may lower the risk of developing bladder cancer.

Objective: Based on evidence that phytoestrogens may protect against prostate cancer, we evaluated the associations between serum enterolactone concentration or dietary phytoestrogen intake and risk of prostate cancer., Methods: In our Swedish population-based case-control study, questionnaire-data were available for 1,499 prostate cancer cases and 1,130 controls, with serum enterolactone levels in a sub-group of 209 cases and 214 controls. Unconditional logistic regression was performed to estimate multivariate odds ratios (ORs) and 95% confidence intervals (CIs) for associations with risk of prostate cancer., Results: High intake of food items rich in phytoestrogens was associated with a decreased risk of prostate cancer. The OR comparing the highest to the lowest quartile of intake was 0.74 (95% CI: 0.57-0.95; p-value for trend: 0.01). In contrast, we found no association between dietary intake of total or individual lignans or isoflavonoids and risk of prostate cancer. Intermediate serum levels of enterolactone were associated with a decreased risk of prostate cancer. The ORs comparing increasing quartiles of serum enterolactone concentration to the lowest quartile were, respectively, 0.28 (95% CI: 0.15-0.55), 0.63 (95% CI: 0.35-1.14) and 0.74 (95% CI: 0.41-1.32)., Conclusions: Our results support the hypothesis that certain foods high in phytoestrogens are associated with a lower risk of prostate cancer.

Dairy intake has been associated with increased risk of advanced prostate cancer. Two US cohort studies reported increased prostate cancer-specific mortality with increased high-fat milk intake. We examined whether dairy and related nutrient intake were associated with prostate cancer progression in a Swedish patient population with high dairy consumption. We prospectively followed 525 men with newly diagnosed prostate cancer (diagnosed 1989-1994). We identified and confirmed deaths through February 2011 ( n = 222 prostate cancer-specific, n = 268 from other causes). Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the associations between food or nutrient intake and prostate cancer-specific death. On average, patients consumed 5.0 servings/day of total dairy products at diagnosis. In the whole population, high-fat milk intake was not associated with prostate cancer-specific death (95% CI: 0.78, 2.10; p-trend = 0.32; multivariate-adjusted model). However, among patients diagnosed with localized prostate cancer, compared to men who consumed <1 servings/day of high-fat milk, those who drank ≥3 servings/day had an increased hazard of prostate cancer mortality (HR = 6.10; 95% CI: 2.14, 17.37; p-trend = 0.004; multivariate-adjusted model). Low-fat milk intake was associated with a borderline reduction in prostate cancer death among patients with localized prostate cancer. These associations were not observed among patients diagnosed with advanced stage prostate cancer. Our data suggest a positive association between high-fat milk intake and prostate cancer progression among patients diagnosed with localized prostate cancer. Further studies are warranted to investigate this association and elucidate the mechanisms by which high-fat milk intake may promote prostate cancer progression. [ABSTRACT FROM AUTHOR]