Total-, LDL-, and HDL-cholesterol, apolipoproteins, and triglycerides with risk of total and fatal prostate cancer in Black and White men in the ARIC study.

BACKGROUND: Cholesterol reduction is considered a mechanism through which cholesterol-lowering drugs including statins are associated with a reduced aggressive prostate cancer risk. While prior cohort studies found positive associations between total cholesterol and more advanced stage and grade in White men, whether associations for total cholesterol, low (LDL)- and high (HDL)-density lipoprotein cholesterol, apolipoprotein B (LDL particle) and A1 (HDL particle), and triglycerides are similar for fatal prostate cancer and in Black men, who experience a disproportionate burden of total and fatal prostate cancer, is unknown. METHODS: We conducted a prospective study of 1553 Black and 5071 White cancer-free men attending visit 1 (1987-1989) of the Atherosclerosis Risk in Communities Study. A total of 885 incident prostate cancer cases were ascertained through 2015, and 128 prostate cancer deaths through 2018. We estimated multivariable-adjusted hazard ratios (HRs) of total and fatal prostate cancer per 1-standard deviation increments and for tertiles (T1-T3) of time-updated lipid biomarkers overall and in Black and White men. RESULTS: Greater total cholesterol concentration (HR per-1 SD = 1.25; 95% CI = 1.00-1.58) and LDL cholesterol (HR per-1 SD = 1.26; 95% CI = 0.99-1.60) were associated with higher fatal prostate cancer risk in White men only. Apolipoprotein B was nonlinearly associated with fatal prostate cancer overall (T2 vs. T1: HR = 1.66; 95% CI = 1.05-2.64) and in Black men (HR = 3.59; 95% CI = 1.53-8.40) but not White men (HR = 1.13; 95% CI = 0.65-1.97). Tests for interaction by race were not statistically significant. CONCLUSIONS: These findings may improve the understanding of lipid metabolism in prostate carcinogenesis by disease aggressiveness, and by race while emphasizing the importance of cholesterol control.

Association between pre-diagnostic circulating adipokines and colorectal cancer and adenoma in the CLUE II cohort.

OBJECTIVE: Obesity is a known risk factor for colorectal cancer (CRC) and adenoma. Obese individuals have higher circulating concentrations of certain endocrine and immune factors produced by adipocytes thought to partially underlie the association between obesity and colorectal neoplasia. Thus, we evaluated the association of plasma concentrations of adiponectin, leptin, and soluble tumor necrosis factor receptor-2 (sTNFR2) with CRC and adenoma. METHODS: We ascertained 193 CRC cases and 193 matched controls, and 131 colorectal adenoma cases and 131 matched controls who had had an endoscopy nested in the CLUE II cohort of Washington County, MD. Plasma markers were measured using ELISA. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from conditional logistic regression for quartiles of the plasma markers separately for CRC and adenoma. RESULTS: Adjusting for leptin and adiponectin, sTNFR2 was positively associated with CRC only in men (Q4 vs. Q1: OR = 3.14, 95% CI 1.11-8.86), which was unchanged adjusting for BMI (3.46, 95% CI 1.19-10.06). Leptin and adiponectin were not associated with CRC risk overall or in men or women. Adiponectin, leptin, and sTNFR2 were not associated with adenoma risk overall or in men or women. CONCLUSION: In this study, leptin and adiponectin were not associated with colorectal carcinogenesis and thus do not appear to underlie the association between obesity and colorectal carcinogenesis. sTNFR2, which we measured as a correlate of TNF-α, was positively associated with CRC in men adjusting for BMI, suggesting that TNF-α may influence colorectal carcinogenesis independent of adipocyte production.

Adding the Team into T1 Translational Research: A Case Study of Multidisciplinary Team Science in the Evaluation of Biomarkers of Prostate Cancer Risk and Prognosis.

BACKGROUND: Given translational research challenges, multidisciplinary team science is promoted to increase the likelihood of moving from discovery to health effect. We present a case study documenting the utility of multidisciplinary team science in prostate cancer tissue biomarker validation. METHODS: We used primary data generated by a team consisting of a pathologist, cancer biologists, a biostatistician, and epidemiologists. We examined their contributions by phase of biomarker evaluation to identify when, through the practice of team science, threats to internal validity were recognized and solved. Next, we quantified the extent of bias avoided in evaluating the association of Ki67 (immunohistochemistry), stromal cell telomere length (fluorescence in situ hybridization), and microRNA (miRNA) (miR-21, miR-141, miR-221; quantitative RT-PCR) with prostate cancer risk or recurrence in nested case-control studies. RESULTS: Threats to validity were tissue storage time (Ki67, miRNA) and laboratory equipment maintenance (telomeres). Solutions were all in the data analysis phase and involved using tissue storage-time specific cutpoints and/or batch-specific cutpoints. Bias in the regression coefficient for quantiles of each biomarker ranged from 24% to 423%, and the coefficient for the test for trend ranged from 15% to 910%. The interpretation of the associations changed as follows: Ki67, null to positive; stromal cell telomere length, null to positive; miR-21 and miR-141 remained null; miR-221, weak to moderate inverse. CONCLUSIONS: In this case study, we documented the inferential benefits of multidisciplinary team science when the team's collaboration and coordination led to the identification of threats to validity and the implementation of appropriate solutions.

Blood Pressure, Hypertension, and Antihypertensive Medication Use and Risk of Total and Fatal Prostate Cancer in Black and White Men in the Atherosclerosis Risk in Communities (ARIC) Study.

Black men are disproportionately burdened by hypertension and prostate cancer (PCa), and some cohorts suggest hypertension is associated with increased PCa risk. We investigated the association of hypertension and antihypertensive use with total (N = 889; 290 Black, 599 White) and fatal (N = 127; 42 Black, 85 White) PCa risk in 6658 (1578 Black, 5080 White) men in the Atherosclerosis Risk in Communities study. In adjusted Cox models, time-updated untreated stage 1 hypertension (systolic/diastolic blood pressure 130-139/80-89 mmHg) was associated with a higher risk of fatal PCa compared to untreated normal blood pressure (hazard ratio (HR) = 1.95; 95% confidence interval (CI) = 1.03-3.70). Compared to untreated normal/elevated blood pressure (combined given few events in those with untreated normal blood pressure), the association was significant in Black (HR = 3.35; 95% CI = 1.27-8.83), but not White (HR = 1.21; 95% CI = 0.58-2.55) men. Ever antihypertensive use was associated with a lower risk of fatal PCa compared to never use (HR = 0.52; 95% CI = 0.31-0.87), including short-term (< 10 years) and long-term (310 years) use (p-trend = 0.02) with similar inverse associations in Black and White men. Hypertension and antihypertensive use were not significantly associated with total PCa. The positive association of untreated stage 1 hypertension and fatal PCa warrants additional confirmation, especially in Black men, and characterization of the underlying mechanism.

Lipid-Lowering Drug Use and Cancer Incidence and Mortality in the ARIC Study.

Background: Lipid-lowering drugs, particularly statins, are associated with reduced incidence of certain cancers in some studies. Associations with cancer mortality are not well studied, and whether associations are similar across race is unknown. Methods: We conducted a prospective analysis of 12 997 cancer-free participants in the Atherosclerosis Risk in Communities Study who were never users at visit 1 (1987-1989). Ever use, duration of use, and age at first use were modeled as time-dependent variables using Cox regression to estimate associations with total, obesity- and smoking-associated, bladder, breast, colorectal, lung, and prostate cancer incidence and mortality. Results: We ascertained 3869 cancer cases and 1661 cancer deaths in 237 999 or more person-years. At 6 years of follow-up, 70.8% of lipid-lowering drug use was a statin. Compared with never use, ever use was associated with lower total, obesity- and smoking-associated cancer mortality and with colorectal cancer mortality (hazard ratio [HR] = 0.50, 95% confidence interval [CI] = 0.32 to 0.79) and incidence (HR = 0.69, 95% CI = 0.53 to 0.92). Inverse associations were consistent by sex and race. Shorter-term use was associated with bladder cancer incidence in men (<10 years: HR = 1.67, 95% CI = 1.02 to 2.73). First use at age 60 years or older was inversely associated with: total mortality, obesity- and smoking-associated mortality, and colorectal cancer mortality; and total incidence, obesity- and smoking-associated incidence, and breast, colorectal, and prostate cancer incidence. Conclusions: This study provides additional evidence for inverse associations between lipid-lowering drug use and cancer incidence and mortality but a positive association with bladder cancer incidence in men. Evaluation of the impact of chemoprevention strategies that include lipid-lowering drugs on population-level cancer burden is needed.

An umbrella review of the evidence associating diet and cancer risk at 11 anatomical sites.

There is evidence that diet and nutrition are modifiable risk factors for several cancers, but associations may be flawed due to inherent biases. Nutritional epidemiology studies have largely relied on a single assessment of diet using food frequency questionnaires. We conduct an umbrella review of meta-analyses of observational studies to evaluate the strength and validity of the evidence for the association between food/nutrient intake and risk of developing or dying from 11 primary cancers. It is estimated that only few single food/nutrient and cancer associations are supported by strong or highly suggestive meta-analytic evidence, and future similar research is unlikely to change this evidence. Alcohol consumption is positively associated with risk of postmenopausal breast, colorectal, esophageal, head & neck and liver cancer. Consumption of dairy products, milk, calcium and wholegrains are inversely associated with colorectal cancer risk. Coffee consumption is inversely associated with risk of liver cancer and skin basal cell carcinoma.

Use of Aspirin and Statins in Relation to Inflammation in Benign Prostate Tissue in the Placebo Arm of the Prostate Cancer Prevention Trial.

Aspirin and statin use may lower the risk of advanced/fatal prostate cancer, possibly by reducing intraprostatic inflammation. To test this hypothesis, we investigated the association of aspirin and statin use with the presence and extent of intraprostatic inflammation, and the abundance of specific immune cell types, in benign prostate tissue from a subset of men from the placebo arm of the Prostate Cancer Prevention Trial. Men were classified as aspirin or statin users if they reported use at baseline or during the 7-year trial. Presence and extent of inflammation were assessed, and markers of specific immune cell types (CD4, CD8, FoxP3, CD68, and c-KIT) were scored, in slides from end-of-study prostate biopsies taken irrespective of clinical indication, per trial protocol. Logistic regression was used to estimate associations between medication use and inflammation measures, adjusted for potential confounders. Of 357 men included, 61% reported aspirin use and 32% reported statin use. Prevalence and extent of inflammation were not associated with medication use. However, aspirin users were more likely to have low FoxP3, a T regulatory cell marker [OR, 5.60; 95% confidence interval (CI), 1.16-27.07], and statin users were more likely to have low CD68, a macrophage marker (OR, 1.63; 95% CI, 0.81-3.27). If confirmed, these results suggest that these medications may alter the immune milieu of the prostate, which could potentially mediate effects of these medications on advanced/fatal prostate cancer risk.

Hyperglycemia, Classified with Multiple Biomarkers Simultaneously in Men without Diabetes, and Risk of Fatal Prostate Cancer.

The association between hyperglycemia and prostate cancer risk is inconsistent, and its association with prostate cancer mortality is understudied. Thus, we investigated the association between hyperglycemia and prostate cancer risk and mortality using multiple biomarkers simultaneously to classify hyper- and normoglycemia. We conducted a prospective analysis of 5,162 cancer-free men attending visit 2 (1990-1992) of the Atherosclerosis Risk in Communities (ARIC) study followed for total (N = 671) and lethal (N = 69) prostate cancer incidence and prostate cancer mortality (N = 64) through 2012. Men without diagnosed diabetes were classified as normo- or hyperglycemic using joint categories of fasting glucose, glycated hemoglobin, and glycated albumin (or fructosamine) defined by clinical or research cutpoints. We evaluated the multivariable-adjusted association of hyperglycemia with prostate cancer incidence and mortality using Cox proportional hazards regression; men with diagnosed diabetes were included as a separate exposure category. Among 4,753 men without diagnosed diabetes, 61.5% were classified as having hyperglycemia (high on ≥1 biomarker). HbA1c and glycated albumin together classified 61.9% of 1,736 men with normal fasting glucose as normoglycemic. Compared with men who were normal on all three biomarkers, men who were high on ≥1 biomarker had an increased risk of lethal [HR, 2.50; 95% confidence interval (CI), 1.12-5.58] and fatal (HR, 3.20; 95% CI, 1.26-8.48) disease, but not total prostate cancer incidence (HR, 0.98; 95% CI, 0.81-1.20); associations were similar including fructosamine instead of glycated albumin. Our findings indicate hyperglycemia is associated with an increased risk of lethal and fatal prostate cancer, but not total prostate cancer incidence.

When Is Enough, Enough? When Are More Observational Epidemiologic Studies Needed to Resolve a Research Question: Illustrations Using Biomarker-Cancer Associations.

BACKGROUND: Research reproducibility is vital for translation of epidemiologic findings. However, repeated studies of the same question may be undertaken without enhancing existing knowledge. To identify settings in which additional research is or is not warranted, we adapted research synthesis metrics to determine number of additional observational studies needed to change the inference from an existing meta-analysis. METHODS: The fail-safe number (FSN) estimates number of additional studies of average weight and null effect needed to drive a statistically significant meta-analysis to null (P ≥ 0.05). We used conditional power to determine number of additional studies of average weight and equivalent heterogeneity to achieve 80% power in an updated meta-analysis to detect the observed summary estimate as statistically significant. We applied these metrics to a curated set of 98 meta-analyses on biomarkers and cancer risk. RESULTS: Both metrics were influenced by number of studies, heterogeneity, and summary estimate size in the existing meta-analysis. For the meta-analysis on Helicobacter pylori and gastric cancer with 15 studies [OR = 2.29; 95% confidence interval (CI), 1.71-3.05], FSN was 805 studies, supporting futility of further study. For the meta-analysis on dehydroepiandrosterone sulfate and prostate cancer with 7 studies (OR = 1.29; 95% CI, 0.99-1.69), 5 more studies would be needed for 80% power, suggesting further study could change inferences. CONCLUSIONS: Along with traditional assessments, these metrics could be used by stakeholders to decide whether additional studies addressing the same question are needed. IMPACT: Systematic application of these metrics could lead to more judicious use of resources and acceleration from discovery to population-health impact.