Prostate cancer: is it time to expand the research focus to early-life exposures?

A prospective study of birth weight and prostate cancer risk and mortality in the Health Professionals Follow-up Study

BACKGROUND

Previous studies have observed inconsistent associations between birth weight and aggressive prostate cancer risk. This study aimed to prospectively analyse this association in the Health Professionals Follow-up Study (HPFS).

METHODS

Birth weight was self-reported in 1994, and prostate cancer diagnoses were assessed biennially through January 2017 and confirmed by medical record review. Multivariable Cox proportional hazards regression was used to evaluate the association between birth weight and prostate cancer risk and mortality.

RESULTS

Among 19,889 eligible men, 2520 were diagnosed with prostate cancer, including 643 with higher-grade/advanced stage, 296 with lethal, and 248 with fatal disease. Overall, no association was observed for increasing birth weight with risk of overall prostate cancer, lower-grade, and organ-confined disease. However, a borderline statistically significant positive trend was observed for increasing birth weight with risk of higher-grade and/or advanced-stage prostate cancer (adjusted hazard ratio [HRadj] per pound: 1.05; 95% confidence interval [CI]: 0.99-1.11; P-trend = 0.08), but no associations were observed with risk of lethal or fatal disease (HRadj: 0.99, 95% CI: 0.91-1.08; P-trend = 0.83; and HRadj: 0.99, 95% CI: 0.90-1.08; P-trend = 0.82, respectively).

CONCLUSION

No consistent associations were observed between birth weight and prostate cancer risk or mortality in this 22-year prospective cohort study.

Orchestration of miRNA Patterns by Testosterone and Dietary Tomato Carotenoids during Early Prostate Carcinogenesis in TRAMP Mice

BACKGROUND

The integrative effects of prostate cancer risk factors, such as diet and endocrine status, on cancer-associated miRNA expression are poorly defined.

OBJECTIVES

This study aimed to define the influence of androgens and diet (tomato and lycopene) on prostatic miRNA expression during early carcinogenesis in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model.

METHODS

Wild type (WT) and TRAMP mice were fed control, tomato-containing, or lycopene-containing diets from 4 to 10 weeks of age. Mice underwent either sham (intact) or castration surgery at 8 wk, and half of the castrated mice received testosterone (2.5 mg/kg body weight/d) at 9 wk. Mice were killed at 10 wk, and dorsolateral prostate expression of 602 miRNAs was assessed.

RESULTS

We detected expression of 88 miRNAs (15% of 602), all of which were present in the TRAMP, in comparison with 49 miRNAs being detectable (8%) in WT. Expression of 61 miRNAs differed by TRAMP genotype, with the majority upregulated in TRAMP. Of the 61 miRNAs, 42 were responsive to androgen status. Diet affected 41% of the miRNAs, which differed by genotype (25/61) and 48% of the androgen-sensitive miRNAs (20/42), indicating overlapping genetic and dietary influences on prostate miRNAs. Tomato and lycopene feeding influenced miRNAs previously associated with the regulation of androgen (miR-145 and let-7), MAPK (miR-106a, 204, 145/143, and 200b/c), and p53 signaling (miR-125 and miR-98) pathways.

CONCLUSIONS

Expression of miRNAs in early prostate carcinogenesis is sensitive to genetic, endocrine, and diet drivers, suggesting novel mechanisms by which tomato and lycopene feeding modulate early prostate carcinogenesis.

Circulating free testosterone and risk of aggressive prostate cancer: Prospective and Mendelian randomisation analyses in international consortia

Previous studies had limited power to assess the associations of testosterone with aggressive disease as a primary endpoint. Further, the association of genetically predicted testosterone with aggressive disease is not known. We investigated the associations of calculated free and measured total testosterone and sex hormone-binding globulin (SHBG) with aggressive, overall and early-onset prostate cancer. In blood-based analyses, odds ratios (OR) and 95% confidence intervals (CI) for prostate cancer were estimated using conditional logistic regression from prospective analysis of biomarker concentrations in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group (up to 25 studies, 14 944 cases and 36 752 controls, including 1870 aggressive prostate cancers). In Mendelian randomisation (MR) analyses, using instruments identified using UK Biobank (up to 194 453 men) and outcome data from PRACTICAL (up to 79 148 cases and 61 106 controls, including 15 167 aggressive cancers), ORs were estimated using the inverse-variance weighted method. Free testosterone was associated with aggressive disease in MR analyses (OR per 1 SD = 1.23, 95% CI = 1.08-1.40). In blood-based analyses there was no association with aggressive disease overall, but there was heterogeneity by age at blood collection (OR for men aged <60 years 1.14, CI = 1.02-1.28; Phet  = .0003: inverse association for older ages). Associations for free testosterone were positive for overall prostate cancer (MR: 1.20, 1.08-1.34; blood-based: 1.03, 1.01-1.05) and early-onset prostate cancer (MR: 1.37, 1.09-1.73; blood-based: 1.08, 0.98-1.19). SHBG and total testosterone were inversely associated with overall prostate cancer in blood-based analyses, with null associations in MR analysis. Our results support free testosterone, rather than total testosterone, in the development of prostate cancer, including aggressive subgroups.

Somatic mutational profiles and germline polygenic risk scores in human cancer

BACKGROUND

The mutational profile of cancer reflects the activity of the mutagenic processes which have been operative throughout the lineage of the cancer cell. These processes leave characteristic profiles of somatic mutations called mutational signatures. Mutational signatures, including single-base substitution (SBS) signatures, may reflect the effects of exogenous or endogenous exposures.

METHODS

We used polygenic risk scores (PRS) to summarize common germline variation associated with cancer risk and other cancer-related traits and examined the association between somatic mutational profiles and germline PRS in 12 cancer types from The Cancer Genome Atlas. Somatic mutational profiles were constructed from whole-exome sequencing data of primary tumors. PRS were calculated for the 12 selected cancer types and 9 non-cancer traits, including cancer risk determinants, hormonal factors, and immune-mediated inflammatory diseases, using germline genetic data and published summary statistics from genome-wide association studies.

RESULTS

We found 17 statistically significant associations between somatic mutational profiles and germline PRS after Bonferroni correction (p < 3.15 × 10^-5), including positive associations between germline inflammatory bowel disease PRS and number of somatic mutations attributed to signature SBS1 in prostate cancer and APOBEC-related signatures in breast cancer. Positive associations were also found between age at menarche PRS and mutation counts of SBS1 in overall and estrogen receptor-positive breast cancer. Consistent with prior studies that found an inverse association between the pubertal development PRS and risk of prostate cancer, likely reflecting hormone-related mechanisms, we found an inverse association between age at menarche PRS and mutation counts of SBS1 in prostate cancer. Inverse associations were also found between several cancer PRS and tumor mutation counts.

CONCLUSIONS

Our analysis suggests that there are robust associations between tumor somatic mutational profiles and germline PRS. These may reflect the mechanisms through hormone regulation and immune responses that contribute to cancer etiology and drive cancer progression.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

Longitudinal trajectories of lifetime body shape and prostate cancer angiogenesis

Angiogenesis potentially underlies the pathway between excess adiposity and prostate carcinogenesis. This study examined the association between lifetime body shape trajectories and prostate cancer angiogenesis. 521 prostate cancer patients who underwent prostatectomy or transurethral resection between 1986 and 2000 were enrolled from the Health Professionals Follow-up Study. Cancers were immunostained and quantitated for cancer vessel regularity, diameter, area, and density, and composite angiogenesis (factor analysis). To identify distinct groups of body shape change, we conducted group-based trajectory modeling. We used multivariable linear regression to estimate the percentage difference in angiogenesis score and 95% confidence interval (CI) between body shape change trajectories during lifetime (age 5-60 years), early life (age 5-30 years), or later life (age 30-60 years). Compared to men with lifetime lean or medium body shape, higher angiogenesis scores were observed in men with moderate increase [percentage difference of 35% (95% CI 5-64)], marked increase [24% (95% CI - 2 to 51)], and constantly heavy with mild increase body shape [38% (95% CI 8-69)]. However, a lower angiogenesis score was noted in men with early-life marked increase (- 22%, 95% CI - 44 to 0) and stable medium body shape (- 14%, 95% CI - 40 to 12), compared to moderate increase body shape. Increased angiogenesis was also found for absolute weight gain from age 21-60 years. Lifetime body fatness accumulation, especially after age 21, was associated with increased prostate cancer angiogenesis, while weight gain in early-life adulthood was associated with lower cancer angiogenesis.

Prenatal Diethylstilbestrol Exposure and Cancer Risk in Males

BACKGROUND

The influence of prenatal diethylstilbestrol (DES) exposure on cancer incidence among middle-aged men has not been well-characterized. We investigated whether exposure to DES before birth impacts overall cancer risk, and risk of site-specific cancers.

METHODS

Men (mean age in 2016 = 62.0 years) who were or were not prenatally DES exposed were identified between 1953 and 1994 and followed for cancer primarily via questionnaire approximately every 5 years between 1994 and 2016. The overall and site-specific cancer rates of the two groups were compared using Poisson regression and proportional hazards modeling with adjustment for age.

RESULTS

DES exposure was not associated with either overall cancer [hazard ratio (HR), 0.94; 95% confidence interval (CI), 0.77-1.15] or total prostate cancer rates (HR, 0.95; 95% CI, 0.68-1.33), but was inversely associated with urinary tract cancer incidence (HR, 0.48; 95% CI, 0.23-1.00).

CONCLUSIONS

There was no increase in either overall or prostate cancer rates among men prenatally DES exposed relative to those unexposed. An unexpected risk reduction was observed for urinary system cancers among the exposed relative to those unexposed. These findings suggest that prenatal DES exposure is unlikely to be an important contributor to cancer development in middle-aged men.

IMPACT

The results of this study could lend reassurance to middle-aged men who were prenatally DES exposed that their exposure does not adversely influence their overall cancer risk.

Adolescent Plant Product Intake in Relation to Later Prostate Cancer Risk and Mortality in the NIH-AARP Diet and Health Study

BACKGROUND

Although fruit and vegetable intake during adolescence, a potentially sensitive time period for prostate cancer (PCa) development, has been proposed to protect against PCa risk, few studies have investigated the role of adolescent plant product intake in PCa development.

METHODS

Intake of various vegetables, fruit, and grains by males at ages 12-13 y was examined in relation to later PCa risk and mortality in the NIH-AARP Diet and Health Study. Cox proportional hazards regression was used to calculate HRs and 95% CIs of nonadvanced (n = 14,238) and advanced (n = 2,170) PCa incidence and PCa mortality (n = 760) during 1,729,896 person-years of follow-up.

RESULTS

None of the plant products examined were associated consistently with all PCa outcomes. However, greater adolescent intakes of tomatoes (P-trend = 0.004) and nonstarch vegetables (P-trend = 0.025) were associated with reduced risk of nonadvanced PCa, and greater intakes of broccoli (P-trend = 0.050) and fruit juice (P-trend = 0.019-0.025) were associated with reduced risk of advanced PCa and/or PCa mortality. Positive trends were also observed for greater intakes of fruit juice (P-trend = 0.002), total fruit (P-trend = 0.014), and dark bread (P-trend = 0.035) with nonadvanced PCa risk and for greater intakes of legumes (P-trend < 0.001), fiber (P-trend = 0.001), and vegetable protein (P-trend = 0.013-0.040) with advanced PCa risk or PCa mortality.

CONCLUSIONS

Our findings do not provide strong evidence to suggest that adolescent plant product intake is associated with reduced PCa risk.

Adolescent animal product intake in relation to later prostate cancer risk and mortality in the NIH-AARP Diet and Health Study

BACKGROUND

Adolescent intake of animal products has been proposed to contribute to prostate cancer (PCa) development because of its potentially carcinogenic constituents and influence on hormone levels during adolescence.

METHODS

We used data from 159,482 participants in the NIH-AARP Diet and Health Study to investigate associations for recalled adolescent intake of red meat (unprocessed beef and processed red meat), poultry, egg, canned tuna, animal fat and animal protein at ages 12-13 years with subsequent PCa risk and mortality over 14 years of follow-up. Cox proportional hazard regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of total (n = 17,349), advanced (n = 2,297) and fatal (n = 804) PCa.

RESULTS

Suggestive inverse trends were observed for adolescent unprocessed beef intake with risks of total, advanced and fatal PCa (multivariable-adjusted P-trends = 0.01, 0.02 and 0.04, respectively). No consistent patterns of association were observed for other animal products by PCa outcome.

CONCLUSION

We found evidence to suggest that adolescent unprocessed beef intake, or possibly a correlate of beef intake, such as early-life socioeconomic status, may be associated with reduced risk and mortality from PCa. Additional studies with further early-life exposure information are warranted to better understand this association.

Alcohol intake in early adulthood and risk of colorectal cancer: three large prospective cohort studies of men and women in the United States

Heavy alcohol consumption in mid-adulthood is an established risk factor of colorectal cancer (CRC). Alcohol use in early adulthood is common, but its association with subsequent CRC risk remains largely unknown. We prospectively investigated the association of average alcohol intake in early adulthood (age 18-22) with CRC risk later in life among 191,543 participants of the Nurses' Health Study ([NHS], 1988-2014), NHSII (1989-2015) and Health Professionals Follow-Up Study (1988-2014). Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs), which were pooled using random effects models. We documented 2,624 CRC cases. High alcohol consumption in early adulthood (≥ 15 g/day) was associated with a higher CRC risk (multivariable HR 1.28, 95% CI 0.99-1.66, Ptrend = 0.02; Pheterogeneity = 0.44), after adjusting for potential confounding factors in early adulthood. Among never/light smokers in early adulthood, the risk associated with high alcohol consumption in early adulthood was elevated (HR 1.53, 95% CI 1.04-2.24), compared with those who had < 1 g/day of alcohol intake. The suggestive higher CRC risk associated with high alcohol consumption in early adulthood was similar in those who had < 15 g/day (HR 1.35, 95% CI 0.98-1.86) versus ≥ 15 g/day of midlife alcohol intake (HR 1.35, 95% CI 0.89-2.05), compared with nondrinkers in both life stages. The findings from these large prospective cohort studies suggest that higher alcohol intake in early adulthood may be associated with a higher risk of developing CRC later in life.

Title Changes in the Mineral Composition of Rat Femoral Bones Induced by Implantation of LNCaP Prostate Cancer Cells and Dietary Supplementation

Prostate cancer (PCa) is the second most frequent cancer in men and the fifth most common cause of death worldwide, with an estimated 378,553 deaths in 2020. Prostate cancer shows a strong tendency to form metastatic foci in the bones. A number of interactions between cancer cells attacking bones and cells of the bone matrix lead to destruction of the bone and growth of the tumour. The last few decades have seen increased interest in the precise role of minerals in human health and disease. Tumour cells accumulate various minerals that promote their intensive growth. Bone, as a storehouse of elements, can be a valuable source of them for the growing tumour. There are also reports suggesting that the presence of some tumours, e.g., of the breast, can adversely affect bone structure even in the absence of metastasis to this organ. This paper presents the effect of chronic dietary intake of calcium, iron and zinc, administered in doses corresponding maximally to twice their level in a standard diet, on homeostasis of selected elements (Ca, K, Zn, Fe, Cu, Sr, Ni, Co, Mn and Mo) in the femoral bones of healthy rats and rats with implanted cancer cells of the LNCaP line. The experiment was conducted over 90 days. After the adaptation period, the animals were randomly divided into four dietary groups: standard diet and supplementation with Zn, Fe and Ca. Every dietary group was divided into experimental group (with implanted cancer cells) and control group (without implanted cancer cells). The cancer cells (LnCaP) were implanted intraperitoneally in the amount 1 × 106 to the rats at day 90 of their lifetime. Bone tissue was dried and treated with microwave-assisted mineral digestation. Total elemental content was quantified by ICP-MS. Student's t-test and Anova or Kruskal-Wallis tests were applied in order to compare treatment and dietary groups. In the case of most of the diets, especially the standard diet, the femoral bones of rats with implanted LNCaP cells showed a clear downward trend in the content of the elements tested, which may be indicative of slow osteolysis taking place in the bone tissue. In the group of rats receiving the standard diet, there were significant reductions in the content of Mo (by 83%), Ca (25%), Co (22%), Mn (13%), K (13%) and Sr (9%) in the bone tissue of rats with implanted LNCaP cells in comparison with the control group receiving the same diet but without LNCaP implantation. Supplementation of the rat diet with calcium, zinc and iron decreased the frequency of these changes relative to the standard diet, which may indicate that the diet had an inhibitory effect on bone resorption in conditions of LNCaP implantation. The principal component analysis (PCA) score plot confirms the pronounced effect of implanted LNCaP cells and the standard diet on bone composition. At the same time, supplementation with calcium, zinc and iron seems to improve bone composition. The microelements that most often underwent quantitative changes in the experimental conditions were cobalt, manganese and molybdenum.

Association of CYP1A1, GSTM1 and GSTT1 gene polymorphisms with risk of prostate cancer in Algerian population

Background

Prostate cancer is the most common cancer in the world, and its etiology involves the interaction of genetic and environmental factors. Interindividual differences observed in the metabolism of xenobiotics may be due to polymorphisms of genes encoding the detoxification enzymes. This genetic variability seems to be associated with differences in susceptibility to certain types of cancers, including prostate cancer. Our study has been made in order to investigate a possible genetic predisposition to prostate cancer in an Algerian population, through the analysis of genetic polymorphisms of three enzymes metabolizing xenobiotics namely cytochrome P450 (CYP) 1A1, glutathione S-transferase mu 1 (GSTM1) and GST theta 1 (GSTT1).

Methods

The current case–control study included 101 prostate cancer patients and 101 healthy controls. Genotyping of CYP1A1 T3801C polymorphisms and GSTM1/GSTT-null was made, respectively, by PCR-RFLP and multiplex PCR.

Results

No significantly positive associations were found for the CYP1A1 T3801C [p = 0.71, OR = 1.23 (0.56–2.72)] and GSTM1-null [p = 0.26, OR = 1.37 (0.76–2.4)] polymorphisms and prostate cancer susceptibility. However, we detect a highly significant association between GSTT1-null genotype [p = 0.03, OR = 2.03 (1.06–3.99)], GSTM1/GSTT1-double null genotype [p = 0.027, OR = 2.6; CI (1.07–6.5)] and prostate cancer risk. Furthermore, no statistically significant differences between the studied polymorphisms and tumor parameters (the Gleason score and clinical stages of aggressiveness) at diagnosis of PCa.

Conclusions

The risk of developing prostate cancer in Algeria does not appear to be associated with CYP1A1 T3801C genotypes and GSTM1-null, but GSTT1-null and GSTM1/GSTT1-double null genotypes increased the risk of prostate cancer.

Body mass index trajectories and prostate cancer risk: Results from the EPICAP study

Elevated body mass index (BMI) has been inconsistently associated with prostate cancer occurrence but it has been suggested that life course adulthood obesity may be associated with an increased risk of prostate cancer. However, few studies have investigated lifetime BMI and prostate cancer risk. We analyzed life course BMI trajectories on prostate cancer risk based on data from the Epidemiological study of Prostate Cancer (EPICAP). We included in our analyses 781 incident prostate cancer cases and 829 controls frequency matched by age. Participants were asked about their weight every decade from age 20 to two years before reference date. BMI trajectories were determined using group-based trajectory modeling to identify groups of men with similar patterns of BMI changes. We identified five BMI trajectories groups. Men with a normal BMI at age 20 developing overweight or obesity during adulthood were at increased risk of aggressive prostate cancer compared to men who maintained a normal BMI. Our results suggest that BMI trajectories resulting in overweight or obesity during adulthood are associated with an increased risk of aggressive prostate cancer, particularly in never smokers, emphasizing the importance of maintaining a healthy BMI throughout adulthood.

Early-Life Cardiorespiratory Fitness and Long-term Risk of Prostate Cancer

BACKGROUND

Adolescence is a period of rapid prostatic growth, yet is understudied for susceptibility for future risk of prostate cancer. We examined cardiorespiratory fitness (CRF) in late adolescence in relation to long-term prostate cancer risk.

METHODS

A population-based cohort study was conducted of all 699,125 Swedish military conscripts during 1972-1985 (97%-98% of 18-year-old men) in relation to risk of prostate cancer overall, aggressive prostate cancer, and prostate cancer mortality during 1998-2017 (ages 50-65 years). CRF was measured by maximal aerobic workload, and prostate cancer was ascertained using the National Prostate Cancer Register. Muscle strength was examined as a secondary predictor.

RESULTS

In 38.8 million person-years of follow-up, 10,782 (1.5%) men were diagnosed with prostate cancer. Adjusting for sociodemographic factors, height, weight, and family history of prostate cancer, high CRF was associated with a slightly increased risk of any prostate cancer [highest vs. lowest quintile: incidence rate ratio (IRR), 1.10; 95% CI, 1.03-1.19; P = 0.008], but was neither significantly associated with aggressive prostate cancer (1.01; 0.85-1.21; P = 0.90) nor prostate cancer mortality (1.24; 0.73-2.13; P = 0.42). High muscle strength also was associated with a modestly increased risk of any prostate cancer (highest vs. lowest quintile: IRR, 1.14; 95% CI, 1.07-1.23; P < 0.001), but neither with aggressive prostate cancer (0.88; 0.74-1.04; P = 0.14) nor prostate cancer mortality (0.81; 0.48-1.37; P = 0.43).

CONCLUSIONS

High CRF or muscle strength in late adolescence was associated with slightly increased future risk of prostate cancer, possibly related to increased screening, but neither with risk of aggressive prostate cancer nor prostate cancer mortality.

IMPACT

These findings illustrate the importance of distinguishing aggressive from indolent prostate cancer and assessing for potential detection bias.

Adolescent dairy product and calcium intake in relation to later prostate cancer risk and mortality in the NIH-AARP Diet and Health Study

PURPOSE

Although a growing body of evidence supports an early-life contribution to prostate cancer (PCa) development, few studies have investigated early-life diet, and only three have examined early-life dairy product intake, a promising candidate risk factor because of its known/suspected influence on insulin-like growth factor levels and height.

METHODS

We used recalled dietary data from 162,816 participants in the NIH-AARP Diet and Health Study to investigate associations for milk, cheese, ice cream, total dairy, and calcium intake at ages 12-13 years with incident total (n = 17,729), advanced (n = 2,348), and fatal PCa (n = 827) over 14 years of follow-up. We calculated relative risks (RRs) and 95% confidence intervals (CIs) by Cox proportional hazards regression.

RESULTS

We observed suggestive positive trends for milk, dairy, and calcium intake with total and/or advanced PCa (p-trends = 0.016-0.148). These trends attenuated after adjustment for additional components of adolescent diet, particularly red meat and vegetables/potatoes. In contrast, suggestive inverse trends were observed for cheese and ice cream intake with total and/or advanced PCa (p-trends = 0.043-0.153), and for milk, dairy, and calcium intake with fatal PCa (p-trend = 0.045-0.117).

CONCLUSION

Although these findings provide some support for a role of adolescent diet in increasing PCa risk, particularly for correlates of milk intake or overall dietary patterns, our protective findings for cheese and ice cream intake with PCa risk and mortality, and for all dairy products with PCa mortality, suggest alternative explanations, such as the influence of early-life socioeconomic status, and increased PCa screening, earlier detection, and better PCa care.

Racial differences in prostate cancer: does timing of puberty play a role?

The burden of prostate cancer has a remarkably disproportionate distribution across racial groups. For example, in the USA, African Americans are twice as likely as individuals of European ancestry to develop or die from prostate cancer, and have a more aggressive disease nature at diagnosis. In contrast, Asian American men have the lowest incidence and mortality rates of prostate cancer. That considerable racial disparities exist even in the subclinical stage of prostate cancer among young men in their 20–30s suggests that patterns of prostate carcinogenesis start to diverge even earlier, perhaps during puberty, when the prostate matures at its most rapid rate. Mendelian randomisation studies have provided strong population-based evidence supporting the hypothesis that earlier onset of puberty increases the risk of prostate cancer—particularly of high grade—and prostate cancer-specific mortality later in life, observations which correspond to the epidemiology of the disease in African Americans. Notably, African American boys initiate genital development ~1 year earlier and thus go through longer periods of pubertal maturation compared with European American boys. In this perspective, bringing together existing evidence, we point to puberty as a potential critical window of increased susceptibility to prostate carcinogenesis that could account for the marked prevailing racial differences in the burden of prostate cancer.

Use of genetic variation to separate the effects of early and later life adiposity on disease risk: mendelian randomisation study

OBJECTIVE

To evaluate whether body size in early life has an independent effect on risk of disease in later life or whether its influence is mediated by body size in adulthood.

DESIGN

Two sample univariable and multivariable mendelian randomisation.

SETTING

The UK Biobank prospective cohort study and four large scale genome-wide association studies (GWAS) consortiums.

PARTICIPANTS

453 169 participants enrolled in UK Biobank and a combined total of more than 700 000 people from different GWAS consortiums.

EXPOSURES

Measured body mass index during adulthood (mean age 56.5) and self-reported perceived body size at age 10.

MAIN OUTCOME MEASURES

Coronary artery disease, type 2 diabetes, breast cancer, and prostate cancer.

RESULTS

Having a larger genetically predicted body size in early life was associated with an increased odds of coronary artery disease (odds ratio 1.49 for each change in body size category unless stated otherwise, 95% confidence interval 1.33 to 1.68) and type 2 diabetes (2.32, 1.76 to 3.05) based on univariable mendelian randomisation analyses. However, little evidence was found of a direct effect (ie, not through adult body size) based on multivariable mendelian randomisation estimates (coronary artery disease: 1.02, 0.86 to 1.22; type 2 diabetes:1.16, 0.74 to 1.82). In the multivariable mendelian randomisation analysis of breast cancer risk, strong evidence was found of a protective direct effect for larger body size in early life (0.59, 0.50 to 0.71), with less evidence of a direct effect of adult body size on this outcome (1.08, 0.93 to 1.27). Including age at menarche as an additional exposure provided weak evidence of a total causal effect (univariable mendelian randomisation odds ratio 0.98, 95% confidence interval 0.91 to 1.06) but strong evidence of a direct causal effect, independent of early life and adult body size (multivariable mendelian randomisation odds ratio 0.90, 0.85 to 0.95). No strong evidence was found of a causal effect of either early or later life measures on prostate cancer (early life body size odds ratio 1.06, 95% confidence interval 0.81 to 1.40; adult body size 0.87, 0.70 to 1.08).

CONCLUSIONS

The findings suggest that the positive association between body size in childhood and risk of coronary artery disease and type 2 diabetes in adulthood can be attributed to individuals remaining large into later life. However, having a smaller body size during childhood might increase the risk of breast cancer regardless of body size in adulthood, with timing of puberty also putatively playing a role.

Relationship of self-reported body size and shape with risk for prostate cancer: A UK case-control study

INTRODUCTION

Previous evidence has suggested a relationship between male self-reported body size and the risk of developing prostate cancer. In this UK-wide case-control study, we have explored the possible association of prostate cancer risk with male self-reported body size. We also investigated body shape as a surrogate marker for fat deposition around the body. As obesity and excessive adiposity have been linked with increased risk for developing a number of different cancers, further investigation of self-reported body size and shape and their potential relationship with prostate cancer was considered to be appropriate.

OBJECTIVE

The study objective was to investigate whether underlying associations exist between prostate cancer risk and male self-reported body size and shape.

METHODS

Data were collected from a large case-control study of men (1928 cases and 2043 controls) using self-administered questionnaires. Data from self-reported pictograms of perceived body size relating to three decades of life (20's, 30's and 40's) were recorded and analysed, including the pattern of change. The associations of self-identified body shape with prostate cancer risk were also explored.

RESULTS

Self-reported body size for men in their 20's, 30's and 40's did not appear to be associated with prostate cancer risk. More than half of the subjects reported an increase in self-reported body size throughout these three decades of life. Furthermore, no association was observed between self-reported body size changes and prostate cancer risk. Using 'symmetrical' body shape as a reference group, subjects with an 'apple' shape showed a significant 27% reduction in risk (Odds ratio = 0.73, 95% C.I. 0.57-0.92).

CONCLUSIONS

Change in self-reported body size throughout early to mid-adulthood in males is not a significant risk factor for the development of prostate cancer. Body shape indicative of body fat distribution suggested that an 'apple' body shape was protective and inversely associated with prostate cancer risk when compared with 'symmetrical' shape. Further studies which investigate prostate cancer risk and possible relationships with genetic factors known to influence body shape may shed further light on any underlying associations.

Placing prostate cancer disparities within a psychosocial context: challenges and opportunities for future research

Black men are more likely to be diagnosed with prostate cancer compared with White men. Despite advances in prevention and treatment strategies, disparities in prostate cancer among Black men persist. While research on the causes of higher incidence and mortality is ongoing, there is limited evidence in the existing literature that clearly speaks to the potential psychological or social factors that may contribute to disparities in prostate cancer incidence. Given the lack of attention to this issue, we review scientific evidence of the ways in which social factors, including socioeconomic status and racial segregation, as well as psychological factors, like depression and anxiety, are related to subsequent prostate cancer risk, which could occur through behavioral and biological processes. Our objective is to illuminate psychosocial factors and their context, using a racial disparity lens, which suggests opportunities for future research on the determinants of prostate cancer. Ultimately, we aim to contribute to a robust research agenda for the development of new prostate cancer prevention measures to reduce racial disparities.

Lifetime recreational physical activity and the risk of prostate cancer

PURPOSE

Research on the association between physical activity and the risk of prostate cancer is inconsistent. The aim of this study was to investigate whether the timing, intensity, and type of recreational physical activity influence prostate cancer risk.

METHODS

A population-based case-control study was conducted in Western Australia in 2001-2002. Data were collected on lifetime recreational physical activity from a self-reported questionnaire. The estimated effects of recreational physical activity on prostate cancer risk were analyzed using logistic regression, adjusting for demographic and lifestyle factors. This analysis included 569 incident cases and 443 controls.

RESULTS

There was a significant, inverse dose-response relationship between vigorous-intensity recreational physical activity between the ages 19 and 34 years and the risk of prostate cancer (p_Trend = 0.013). Participants in the most active quartile of vigorous-intensity physical activity in this age period had a 33% lower risk of prostate cancer than participants in the least active quartile (Adjusted Odds Ratio = 0.67, 95% confidence interval = 0.45-1.01). Moderate-intensity recreational physical activity was not associated with the risk of prostate cancer. Recreational physical activity performed over the lifetime showed no association with prostate cancer risk. Weight training performed from early adulthood onwards showed a non-significant but consistent inverse association with prostate cancer risk. There was no strong evidence that physical activity was differentially associated with the risks of low-grade and medium-to-high grade prostate cancers.

CONCLUSIONS

A high level of vigorous recreational physical activity in early adulthood may be required to reduce the risk of prostate cancer.

Sustained influence of infections on prostate-specific antigen concentration: An analysis of changes over 10 years of follow-up

BACKGROUND

To extend our previous observation of a short-term rise in prostate-specific antigen (PSA) concentration, a marker of prostate inflammation and cell damage, during and immediately following sexually transmitted and systemic infections, we examined the longer-term influence of these infections, both individually and cumulatively, on PSA over a mean of 10 years of follow-up in young active duty U.S. servicemen.

METHODS

We measured PSA in serum specimens collected in 1995-7 (baseline) and 2004-6 (follow-up) from 265 men diagnosed with chlamydia (CT), 72 with gonorrhea (GC), 37 with non-chlamydial, non-gonococcal urethritis (NCNGU), 58 with infectious mononucleosis (IM), 91 with other systemic or non-genitourinary infections such as varicella; and 125-258 men with no infectious disease diagnoses in their medical record during follow-up (controls). We examined the influence of these infections on PSA change between baseline and follow-up.

RESULTS

The proportion of men with any increase in PSA (>0 ng/mL) over the 10-year average follow-up was significantly higher in men with histories of sexually transmitted infections (CT, GC, and NCNGU; 67.7% vs 60.8%, P = 0.043), systemic infections (66.7% vs 54.4%, P = 0.047), or any infections (all cases combined; 68.5% vs 54.4%, P = 0.003) in their military medical record compared to controls.

CONCLUSIONS

While PSA has been previously shown to rise during acute infection, these findings demonstrate that PSA remains elevated over a longer period. Additionally, the overall infection burden, rather than solely genitourinary-specific infection burden, contributed to these long-term changes, possibly implying a role for the cumulative burden of infections in prostate cancer risk.

Evaluating intrinsic and non-intrinsic cancer risk factors

Discriminating the contribution of unmodifiable random intrinsic DNA replication errors ('bad luck') to cancer development from those of other factors is critical for understanding cancer in humans and for directing public resources aimed at reducing the burden of cancer. Here, we review and highlight the evidence that demonstrates cancer causation is multifactorial, and provide several important examples where modification of risk factors has achieved cancer prevention. Furthermore, we stress the need and opportunities to advance understanding of cancer aetiology through integration of interaction effects between risk factors when estimating the contribution of individual and joint factors to cancer burden in a population. We posit that non-intrinsic factors drive most cancer risk, and stress the need for cancer prevention.

Childhood diet and growth in boys in relation to timing of puberty and adult height: the Longitudinal Studies of Child Health and Development

PURPOSE

To begin to explore the possible roles of childhood diet and growth in prostate cancer (PCa) development, we investigated these exposures in relation to two known/suspected PCa risk factors, earlier pubertal timing and greater attained height, in the Longitudinal Studies of Child Health and Development.

METHODS

We used biannual/annual height, weight, and dietary history data to investigate childhood diet, body mass index (BMI), birth length, and childhood height in relation to PCa risk factors (age at peak height velocity (APHV), height at age 13, and adult height) for 64 Caucasian American boys.

RESULTS

In adjusted models, childhood fat and animal protein intake was positively associated with height at age 13 and adult height (P < 0.05). A childhood diet high in fat and animal protein and low in vegetable protein was also associated with earlier APHV (P < 0.05), whereas no associations were observed for childhood energy intake or BMI. Birth length and childhood height were positively associated with height at age 13 and adult height, and childhood height was inversely associated with APHV (P < 0.05).

CONCLUSION

Our findings suggest that both childhood diet and growth potential/growth contribute to earlier pubertal timing and taller attained height in males, supporting roles of these factors in PCa development.

The association of weight change in young adulthood and smoking status with risk of prostate cancer recurrence

The decades before prostate cancer diagnosis represent an etiologically relevant time period for prostate cancer carcinogenesis. However, the association of weight gain in young adulthood with subsequent biochemical recurrence among men with prostate cancer is not well studied, particularly among smokers. We conducted a prospective cohort study of 1,082 men with prostate cancer and treated with either radical prostatectomy or radiation between 2003 and 2010. The association of weight at age 20, weight at age 50 and weight change from age 20 to age 50 with biochemical recurrence was assessed using Cox Proportional Hazards with adjustment for confounders. Stratum-specific hazard ratio (HR) estimates by smoking status were evaluated. In the overall cohort, weight at age 20 (HR per 30 kg: 1.56, 95% confidence interval (CI): 1.02, 2.38, p-trend: 0.039), weight at age 50 (HR per 30 kg: 1.80, 95% CI: 1.32, 2.47, p-trend: <0.001) and weight change from age 20 to age 50 (HR per 30 kg: 1.84, 95% CI: 1.24, 2.74, p-trend: 0.003) were associated with biochemical recurrence. In stratified analyses, weight change from age 20 to age 50 was significantly associated with biochemical recurrence only in former smokers (HR per 30 kg: 3.87, 95% CI: 1.88, 8.00, p-trend: <0.001) and ever smokers (HR per 30 kg: 2.38, 95% CI: 1.27, 4.45, p-trend: 0.007). No significant association was observed between weight gain in young adulthood and biochemical recurrence in never smokers. Our study adds further evidence that weight gain during early adult years conveys long-term risk for adverse cancer outcomes.

Epigenome-wide DNA methylation profiling of periprostatic adipose tissue in prostate cancer patients with excess adiposity-a pilot study

Background

Periprostatic adipose tissue (PPAT) has been recognized to associate with prostate cancer (PCa) aggressiveness and progression. Here, we sought to investigate whether excess adiposity modulates the methylome of PPAT in PCa patients. DNA methylation profiling was performed in PPAT from obese/overweight (OB/OW, BMI > 25 kg m⁻²) and normal weight (NW, BMI < 25 kg m⁻²) PCa patients. Significant differences in methylated CpGs between OB/OW and NW groups were inferred by statistical modeling.

Results

Five thousand five hundred twenty-six differentially methylated CpGs were identified between OB/OW and NW PCa patients with 90.2% hypermethylated. Four hundred eighty-three of these CpGs were found to be located at both promoters and CpG islands, whereas the representing 412 genes were found to be involved in pluripotency of stem cells, fatty acid metabolism, and many other biological processes; 14 of these genes, particularly FADS1, MOGAT1, and PCYT2, with promoter hypermethylation presented with significantly decreased gene expression in matched samples. Additionally, 38 genes were correlated with antigen processing and presentation of endogenous antigen via MHC class I, which might result in fatty acid accumulation in PPAT and tumor immune evasion.

Conclusions

Results showed that the whole epigenome methylation profiles of PPAT were significantly different in OB/OW compared to normal weight PCa patients. The epigenetic variation associated with excess adiposity likely resulted in altered lipid metabolism and immune dysregulation, contributing towards unfavorable PCa microenvironment, thus warranting further validation studies in larger samples.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0490-3) contains supplementary material, which is available to authorized users.

Appendicitis before Age 20 Years Is Associated with an Increased Risk of Later Prostate Cancer

Background: Appendicitis before age 20 years has been observed to influence the risk of several inflammatory conditions, possibly through underlying immunological mechanisms. Inflammation has further been suggested to be involved in prostate cancer development. We therefore hypothesized that immunological characteristics signaled by appendicitis before late adolescence might influence the risk of later prostate cancer, and aimed to evaluate this association in a population-based study.Methods: We identified a large cohort of Swedish men who underwent assessment for military conscription around the age of 18 years (n = 242,573). Medical diagnoses at time of conscription were available through the Swedish Military Conscription Register. The Swedish Cancer Register was used to identify diagnoses of prostate cancer. Multivariable adjusted Cox regression analyses were used to estimate HR and 95% confidence intervals (95% CIs) for the association between appendicitis and prostate cancer.Results: During a median of 36.7 years of follow-up, 1,684 diagnoses of prostate cancer occurred. We found a statistically significant association between appendicitis and overall prostate cancer (adjusted HR 1.70; 95% CI, 1.08-2.67). The risk was notably increased for advanced (HR 4.42; 95% CI, 1.74-11.22) and lethal (HR 8.95; 95% CI, 2.98-26.91) prostate cancer.Conclusions: These results suggest that a diagnosis of appendicitis before adulthood potentially signals underlying immune characteristics and a pattern of inflammatory response relevant to prostate cancer risk.Impact: The study lends support to the proposed role of inflammation in prostate carcinogenesis, and adds another area of investigation potentially relevant to prostate cancer development. Cancer Epidemiol Biomarkers Prev; 27(6); 660-4. ©2018 AACR.

Accelerating the Pace of Cancer Prevention- Right Now

As a nation, we underinvest in prevention and fail to implement strategies that ensure all population groups equitably share in the return on investment in prevention research and the benefits of prevention effectiveness. There is significant evidence indicating that by applying knowledge that we already have to reduce tobacco, inactivity, and obesity (known modifiable causes of cancer), we can prevent more than 50% of cancers. Vaccination against HPV, aspirin and selective estrogen receptor modulators, and screening programs further reduce risk. Evidence-based prevention strategies are inconsistently implemented across the United States. Substantial variation across States indicates that there is much room for improvement in implementation of prevention. Implementation science applies innovative approaches to identifying, understanding, and developing strategies for overcoming barriers to the adoption, adaptation, integration, scale-up, and sustainability of evidence-based interventions, tools, policies, and guidelines that will prevent cancer through application of evidence-based interventions. When we get implementation of prevention programs right and at scale, we achieve substantial population benefits. Although many efforts are underway to maximize our knowledge about the causes and treatments of cancer, we can achieve reductions in the cancer burden right now by doing what we already know. The time to start is now. Cancer Prev Res; 11(4); 171-84. ©2018 AACR.

Risk of early-onset prostate cancer associated with occupation in the Nordic countries

BACKGROUND

Early-onset prostate cancer is often more aggressive and may have a different aetiology than later-onset prostate cancer, but has been relatively little studied to date. We evaluated occupation in relation to early- and later-onset prostate cancer in a large pooled study.

METHODS

We used occupational information from census data in five Nordic countries from 1960 to 1990. We identified prostate cancer cases diagnosed from 1961 to 2005 by linkage of census information to national cancer registries and calculated standardised incidence ratios (SIRs) separately for men aged 30-49 and those aged 50 or older. We also conducted separate analyses by period of follow-up, 1961-1985 and 1986-2005, corresponding to pre- and post-prostate-specific antigen (PSA) screening.

RESULTS

For early-onset prostate cancer (n = 1521), we observed the highest SIRs for public safety workers (e.g. firefighters) (SIR = 1.71, 95% confidence interval [CI]: 1.23-2.31) and military personnel (SIR = 1.97, 95% CI: 1.31-2.85). These SIRs were significantly higher than the SIRs for later-onset disease (for public safety workers, SIR = 1.10, 95% CI: 1.07-1.14 and for military personnel, SIR = 1.09, 95% CI: 1.05-1.13; pheterogeneity = 0.005 and 0.002, respectively). Administrators and technical workers also demonstrated significantly increased risks for early-onset prostate cancer, but the SIRs did not differ from those of later-onset disease (pheterogeneity >0.05). While our early-onset finding for public safety workers was restricted to the post-PSA period, that for military personnel was restricted to the pre-PSA period.

CONCLUSION

Our results suggest that occupational exposures, particularly for military personnel, may be associated with early-onset prostate cancer. Further evaluation is needed to explain these findings.

Prospective investigation of risk factors for prostate cancer in the UK Biobank cohort study

BACKGROUND

Prostate cancer is the most common cancer in British men but its aetiology is not well understood. We aimed to identify risk factors for prostate cancer in British males.

METHODS

We studied 219 335 men from the UK Biobank study who were free from cancer at baseline. Exposure data were collected at recruitment. Prostate cancer risk by the different exposures was estimated using multivariable-adjusted Cox proportional hazards models.

RESULTS

In all, 4575 incident cases of prostate cancer occurred during 5.6 years of follow-up. Prostate cancer risk was positively associated with the following: black ethnicity (hazard ratio black vs white=2.61, 95% confidence interval=2.10-3.24); having ever had a prostate-specific antigen test (1.31, 1.23-1.40); being diagnosed with an enlarged prostate (1.54, 1.38-1.71); and having a family history of prostate cancer (1.94, 1.77-2.13). Conversely, Asian ethnicity (Asian vs white hazard ratio=0.62, 0.47-0.83), excess adiposity (body mass index (⩾35 vs <25 kg m-2=0.75, 0.64-0.88) and body fat (⩾30.1 vs <20.5%=0.81, 0.73-0.89)), cigarette smoking (current vs never smokers=0.85, 0.77-0.95), having diabetes (0.70, 0.62-0.80), and never having had children (0.89, 0.81-0.97) or sexual intercourse (0.53, 0.33-0.84) were related to a lower risk.

CONCLUSIONS

In this new large British prospective study, we identified associations with already-established, putative and possible novel risk factors for being diagnosed with prostate cancer. Future research will examine associations by tumour characteristics.

Tall height and obesity are associated with an increased risk of aggressive prostate cancer: results from the EPIC cohort study

BACKGROUND

The relationship between body size and prostate cancer risk, and in particular risk by tumour characteristics, is not clear because most studies have not differentiated between high-grade or advanced stage tumours, but rather have assessed risk with a combined category of aggressive disease. We investigated the association of height and adiposity with incidence of and death from prostate cancer in 141,896 men in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

Multivariable-adjusted Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). After an average of 13.9 years of follow-up, there were 7024 incident prostate cancers and 934 prostate cancer deaths.

RESULTS

Height was not associated with total prostate cancer risk. Subgroup analyses showed heterogeneity in the association with height by tumour grade (P heterogeneity = 0.002), with a positive association with risk for high-grade but not low-intermediate-grade disease (HR for high-grade disease tallest versus shortest fifth of height, 1.54; 95% CI, 1.18-2.03). Greater height was also associated with a higher risk for prostate cancer death (HR = 1.43, 1.14-1.80). Body mass index (BMI) was significantly inversely associated with total prostate cancer, but there was evidence of heterogeneity by tumour grade (P heterogeneity = 0.01; HR = 0.89, 0.79-0.99 for low-intermediate grade and HR = 1.32, 1.01-1.72 for high-grade prostate cancer) and stage (P heterogeneity = 0.01; HR = 0.86, 0.75-0.99 for localised stage and HR = 1.11, 0.92-1.33 for advanced stage). BMI was positively associated with prostate cancer death (HR = 1.35, 1.09-1.68). The results for waist circumference were generally similar to those for BMI, but the associations were slightly stronger for high-grade (HR = 1.43, 1.07-1.92) and fatal prostate cancer (HR = 1.55, 1.23-1.96).

CONCLUSIONS

The findings from this large prospective study show that men who are taller and who have greater adiposity have an elevated risk of high-grade prostate cancer and prostate cancer death.

Exposure to maternal obesogenic diet worsens some but not all pre-cancer phenotypes in a murine genetic model of prostate cancer

Prostate cancer research has been predominantly focused on adult exposures and risk factors. However, because the prostate develops during gestation and early life, exposure to external factors, such as obesity, during development could affect the prostate cancer progression in adults. Our previous work demonstrated that exposure to a high fat/high sugar (HF/HS) diet during gestation and until weaning stimulated prostate hyperplasia and altered the Pten/Akt pathway in adult mice fed a normal diet after weaning. Here, we asked whether maternal exposure to HF/HS would worsen prostate phenotypes in mice lacking Pten, a widely accepted driver of prostate cancer. We found that, at six weeks of age, both Chow (control)-and HF/HS-exposed Pten knockout mice showed evidence of murine PIN that included ducts with central comedo necrosis but that the HF/HS exposure did not influence murine PIN progression. The Pten knockout mice exposed to HF/HS in utero had significantly more mitotic cells than Pten knockouts exposed to Chow diet. In the Pten null background, the maternal HF/HS diet enhanced proliferation but did not have an additive effect on Akt activation. We observed neuroendocrine differentiation in Pten knockout mice, a phenotype that had not been previously described in this model.

Erectile dysfunction and the risk of prostate cancer

Background

Prostate cancer (PCa) is the most commonly diagnosed malignancy and the third leading cause of cancer death among men in developed countries. Because some risk factors are common between erectile dysfunction (ED) and PCa, we investigated the association between ED and subsequent PCa.

Methods

This nationwide population-based cohort study used data from the Taiwan National Health Insurance Research Database for the period 2000–2010. We identified patients newly diagnosed with ED by using codes from the International Classification of Diseases, Ninth Revision, Clinical Modification.

Results

In total, 5858 and 23432 patients were enrolled in the ED and non-ED cohorts, respectively. After adjustment for age, sex, and comorbidities, the overall incidence densities of PCa were significantly higher in the ED cohort than in the non-ED cohort, with an adjusted hazard ratio (aHR) of 1.19. The age-specific relative risk of PCa was significantly higher for all age groups in the ED cohort than in the non-ED cohort. Compared with patients without ED, those with organic ED had a 1.27-fold higher risk of PCa.

Conclusion

ED is a harbinger of PCa in some men. Physicians should consider the possibility of occult PCa in patients with ED regardless of age and comorbidities.

Marine-derived chromopeptide A, a novel class I HDAC inhibitor, suppresses human prostate cancer cell proliferation and migration

Histone deacetylases (HDACs), especially HDAC1, 2, 3 and 4, are abundantly expressed and over-activated in prostate cancer that is correlated with the poor prognosis. Thus, inhibition of HDAC activity has emerged as a potential alternative option for prostate cancer therapy. Chromopeptide A is a depsipeptide isolated from the marine sediment-derived bacterium Chromobacterium sp. HS-13-94; it has a chemical structure highly similar to FK228, a class I HDAC inhibitor that is approved by FDA for treating T-cell lymphoma. In this study, we determined whether chromopeptide A, like FK228, acted as a class I HDAC inhibitor, and whether chromopeptide A could inhibit the growth and migration of human prostate cancer in vitro and in vivo. HDAC enzyme selectivity and kinetic analysis revealed that chromopeptide A selectively inhibited the enzymatic activities of HDAC1, 2, 3 and 8 in a substrate non-competitive manner with comparable IC₅₀ values for each HDAC member as FK228 in vitro. Importantly, chromopeptide A dose-dependently suppressed the proliferation of human prostate cancer cell lines PC3, DU145 and LNCaP with IC₅₀ values of 2.43±0.02, 2.08±0.16, and 1.75±0.06 nmol/L, respectively, accompanied by dose-dependent inhibition of HDAC enzymatic activity in PC3 and DU145 cells. Chromopeptide A (0.2-50 nmol/L) caused G₂/M phase arrest and induced apoptosis in the prostate cancer cell lines. Moreover, chromopeptide A dose-dependently inhibited the migration of PC3 cells. In mice bearing PC3 prostate cancer xenografts, intravenous injection of chromopeptide A (1.6, 3.2 mg/kg, once a week for 18 d) significantly suppressed the tumor growth, which was associated with increased expression levels of Ac-H3 and p21 in tumor tissues. Our results identify chromopeptide A as a novel class I HDAC inhibitor and provide therapeutic strategies that may be implemented in prostate cancer.

Prediagnostic Body Mass Index Trajectories in Relation to Prostate Cancer Incidence and Mortality in the PLCO Cancer Screening Trial

Background

Evidence suggests that obesity in adulthood is associated with increased risk of "clinically significant" prostate cancer. However, studies of body mass index (BMI) across the adult life course and prostate cancer risks remain limited.

Methods

In a prospective cohort of 69 873 men in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, we examined associations of prediagnostic BMI across the adult life course with risk of incident prostate cancer and fatal prostate cancer (prostate cancer-specific mortality). At 13 years of follow-up, we identified 7822 incident prostate cancer cases, of which 3078 were aggressive and 255 fatal. BMI trajectories were determined using latent-class trajectory modeling. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

BMI at age 20 years, 50 years, and baseline questionnaire (mean age = 63 years) were associated with increased risks of fatal prostate cancer (HRs = 1.27-1.32 per five-unit increase). In five BMI trajectories identified, fatal prostate cancer risk was increased in men who had a normal BMI (HR = 1.95, 95% CI = 1.21 to 3.12) or who were overweight (HR = 2.65, 95% CI = 1.35 to 5.18) at age 20 years and developed obesity by baseline compared with men who maintained a normal BMI. Aggressive and nonaggressive prostate cancer were not associated with BMI, and modest inverse associations were seen for total prostate cancer.

Conclusions

Our results suggest that BMI trajectories during adulthood that result in obesity lead to an elevated risk of fatal prostate cancer.

Anogenital Distance, a Biomarker of Prenatal Androgen Exposure Is Associated With Prostate Cancer Severity

BACKGROUND

Anogenital distance (AGD), the distance from the centre of the anus to the genitals, is a sexually dimorphic phenotype in mammals. Experimental studies have shown that AGD is a biomarker of prenatal androgen exposure during the masculinisation period of development. The aim of this study is to assess the relationship between anogenital distance (AGD), as an indirect marker of prenatal hormonal environment, and prostate cancer (PCa) severity.

MATERIALS

We conducted a cross-sectional study with a total of 120 PCa patients with confirmed biopsy of the tumour from April 2007 to July 2015. Two variants of the anogenital distance were assessed, from the anus to the posterior base of the scrotum (AGD_AS ) and to the cephalad insertion of the penis (AGD_AP ). We compared differences in groups to evaluate the association between AGD measurements and severity of the preoperative biopsy and clinical scores.

RESULTS

Longer AGD_AS was significantly associated with the highest Gleason score (P = 0.015) and D'Amico nomogram (P = 0.048). In contrast, no statistical differences were found in the AGD_AP and severity of the preoperative biopsy.

CONCLUSIONS

These findings are consistent with the hypothesis that a higher prenatal androgen exposure is associated with higher severity of PCa. Prostate 77: 406-411, 2017. © 2016 Wiley Periodicals, Inc.

Prostate cancer risk related to foods, food groups, macronutrients and micronutrients derived from the UK Dietary Cohort Consortium food diaries

BACKGROUND/OBJECTIVES

The influence of dietary factors remains controversial for screen-detected prostate cancer and inconclusive for clinically detected disease. We aimed to examine these associations using prospectively collected food diaries.

SUBJECTS/METHODS

A total of 1,717 prostate cancer cases in middle-aged and older UK men were pooled from four prospective cohorts with clinically detected disease (n=663), with routine data follow-up (means 6.6-13.3 years) and a case-control study with screen-detected disease (n=1054), nested in a randomised trial of prostate cancer treatments (ISCTRN 20141297). Multiple-day food diaries (records) completed by men prior to diagnosis were used to estimate intakes of 37 selected nutrients, food groups and items, including carbohydrate, fat, protein, dairy products, fish, meat, fruit and vegetables, energy, fibre, alcohol, lycopene and selenium. Cases were matched on age and diary date to at least one control within study (n=3528). Prostate cancer risk was calculated, using conditional logistic regression (adjusted for baseline covariates) and expressed as odds ratios in each quintile of intake (±95% confidence intervals). Prostate cancer risk was also investigated by localised or advanced stage and by cancer detection method.

RESULTS

There were no strong associations between prostate cancer risk and 37 dietary factors.

CONCLUSIONS

Prostate cancer risk, including by disease stage, was not strongly associated with dietary factors measured by food diaries in middle-aged and older UK men.

Influence of In Utero Maternal and Neonate Factors on Cord Blood Leukocyte Telomere Length: Clues to the Racial Disparity in Prostate Cancer?

Background. Modifiable factors in adulthood that explain the racial disparity in prostate cancer have not been identified. Because racial differences in utero that may account for this disparity are understudied, we investigated the association of maternal and neonate factors with cord blood telomere length, as a cumulative marker of cell proliferation and oxidative damage, by race. Further, we evaluated whether cord blood telomere length differs by race. Methods. We measured venous umbilical cord blood leukocyte relative telomere length by qPCR in 38 black and 38 white full-term male neonates. Using linear regression, we estimated geometric mean relative telomere length and tested for differences by race. Results. Black mothers were younger and had higher parity and black neonates had lower birth and placental weights. These factors were not associated with relative telomere length, even after adjusting for or stratifying by race. Relative telomere length in black (2.72) and white (2.73) neonates did not differ, even after adjusting for maternal or neonate factors (all p > 0.9). Conclusions. Maternal and neonate factors were not associated with cord blood telomere length, and telomere length did not differ by race. These findings suggest that telomere length at birth does not explain the prostate cancer racial disparity.

Role of vitamin D receptor gene Cdx2 and Apa1 polymorphisms in prostate cancer susceptibility: a meta-analysis

BACKGROUND

Vitamin D receptor (VDR) gene polymorphisms affect the risk of prostate cancer. However, studies investigating the relationship between VDR gene polymorphisms (Cdx2 and ApaI) and prostate cancer risk are equivocal. Therefore, we conducted a meta-analysis of all the studies to review the evidence available.

METHODS

A comprehensive search of PubMed, EMBASE, and ISI Web of Science for studies published until September 2015 was conducted. Odds ratios (ORs) and 95 % confidence intervals (CIs) were analyzed to determine the association between VDR Cdx2 and ApaI polymorphisms, and prostate cancer risk.

RESULTS

The meta-analysis included 10 studies involving 4979 cases and 4380 controls to analyze the VDR Cdx2 polymorphism. An additional 11 studies involving 2837 cases and 2884 controls were analyzed for the VDR ApaI polymorphism. Evidence failed to support the role of VDR Cdx2 and ApaI polymorphisms in prostate cancer. For Cdx2, the pooled OR was 1.11 (95 % CI = 0.93-1.33) for AA vs. GG genotypes, 0.97 (95 % CI = 0.88-1.06) for GA vs. AA genotypes, 0.99 (95 % CI = 0.91-1.08) for AA + GA vs. GG, and 1.12 (95 % CI = 0.95-1.31) for AA vs. GA + GG. No significant relationship was observed in any subgroup analysis based on ethnicity, controls, and Hardy-Weinberg equilibrium (HWE). ORs for the ApaI polymorphism were similar.

CONCLUSIONS

VDR Cdx2 and ApaI polymorphisms are not associated with prostate cancer. Additional evidence is required to confirm this conclusion.

Effect Modification by Time Since Blood Draw on the Association Between Circulating Fatty Acids and Prostate Cancer Risk

A recent meta-analysis suggested that circulating fatty acids do not play an important role in prostate carcinogenesis. We hypothesized that the relation between circulating fatty acids and prostate cancer (PCa) risk is modified by time between blood draw and diagnosis. We tested this hypothesis in a prospective case-control study of 476 PCa cases and matched control subjects nested in the Physicians' Health Study. The previously reported associations between fatty acids and PCa in this cohort were dramatically stronger among men diagnosed 10 or more years after blood collection. Statistically significant effect modification by time since blood collection was identified for mono-unsaturated and poly-unsaturated fatty acids and was more pronounced for aggressive tumors. Among men diagnosed fewer than 10 years since blood collection, the relative risks per interquartile range were 1.03 (95% confidence interval [CI] = 0.86 to 1.25) for total mono-unsaturated fatty acids (MUFA) and 0.95 (95% CI = 0.78 to 1.15) for total poly-unsaturated fatty acids (PUFA) whereas among men diagnosed 10 or more years after blood draw the relative risks per interquartile range were 1.69 (95% CI = 1.21 to 2.34) for MUFA (Pheterogeneity = .01) and 0.59 (95% CI = 0.42 to 0.83) for PUFA (Pheterogeneity = .02). These data suggest that the results of the meta-analysis may be partly explained by insufficient follow-up time. Furthermore, they suggest that some environmental and metabolic factors may play a role in prostate carcinogenesis decades before clinical identification of this disease.

Pubertal development and prostate cancer risk: Mendelian randomization study in a population-based cohort

BACKGROUND

Epidemiological studies have observed a positive association between an earlier age at sexual development and prostate cancer, but markers of sexual maturation in boys are imprecise and observational estimates are likely to suffer from a degree of uncontrolled confounding. To obtain causal estimates, we examined the role of pubertal development in prostate cancer using genetic polymorphisms associated with Tanner stage in adolescent boys in a Mendelian randomization (MR) approach.

METHODS

We derived a weighted genetic risk score for pubertal development, combining 13 SNPs associated with male Tanner stage. A higher score indicated a later puberty onset. We examined the association of this score with prostate cancer risk, stage and grade in the UK-based ProtecT case-control study (n = 2,927), and used the PRACTICAL consortium (n = 43,737) as a replication sample.

RESULTS

In ProtecT, the puberty genetic score was inversely associated with prostate cancer grade (odds ratio (OR) of high- vs. low-grade cancer, per tertile of the score: 0.76; 95 % CI, 0.64-0.89). In an instrumental variable estimation of the causal OR, later physical development in adolescence (equivalent to a difference of one Tanner stage between pubertal boys of the same age) was associated with a 77 % (95 % CI, 43-91 %) reduced odds of high Gleason prostate cancer. In PRACTICAL, the puberty genetic score was associated with prostate cancer stage (OR of advanced vs. localized cancer, per tertile: 0.95; 95 % CI, 0.91-1.00) and prostate cancer-specific mortality (hazard ratio amongst cases, per tertile: 0.94; 95 % CI, 0.90-0.98), but not with disease grade.

CONCLUSIONS

Older age at sexual maturation is causally linked to a reduced risk of later prostate cancer, especially aggressive disease.

Childhood height, adult height, and the risk of prostate cancer

PURPOSE

We previously showed that childhood height is positively associated with prostate cancer risk. It is, however, unknown whether childhood height exerts its effects independently of or through adult height. We investigated whether and to what extent childhood height has a direct effect on the risk of prostate cancer apart from adult height.

METHODS

We included 5,871 men with height measured at ages 7 and 13 years in the Copenhagen School Health Records Register who also had adult (50-65 years) height measured in the Danish Diet, Cancer and Health study. Prostate cancer status was obtained through linkage to the Danish Cancer Registry. Direct and total effects of childhood height on prostate cancer risk were estimated from Cox regressions.

RESULTS

From 1996 to 2012, 429 prostate cancers occurred. Child and adult heights were positively and significantly associated with prostate cancer risk. When adjusted for adult height, height at age 7 years was no longer significantly associated with the risk of prostate cancer. Height at 13 years was significantly and positively associated with prostate cancer risk even when adult height was adjusted for; per height z-score the hazard ratio was 1.15 [95% confidence interval (CI) 1.01-1.32].

CONCLUSIONS

The effect of height at 13 years on the risk of prostate cancer was not entirely mediated through adult height, suggesting that child height and adult height may be associated with prostate cancer through different pathways.

Is birthweight associated with total and aggressive/lethal prostate cancer risks? A systematic review and meta-analysis

Background:

It has been hypothesised that intrauterine exposures are important for subsequent prostate cancer risk. Prior epidemiological studies have used birthweight as a proxy of cumulative intrauterine exposures to test this hypothesis, but results have been inconsistent partly because of limited statistical power.

Methods:

We investigated birthweight in relation to prostate cancer in the Medical Research Council (MRC) National Survey of Health and Development (NSHD) using Cox proportional hazards models. We then conducted a meta-analysis of birthweight in relation to total and aggressive/lethal prostate cancer risks, combining results from the NSHD analysis with 13 additional studies on this relationship identified from a systematic search in four major scientific literature databases through January 2015.

Results:

Random-effects models found that per kg increase in birthweight was positively associated with total (OR=1.02, 95% confidence interval (95% CI)=1.00, 1.05; I²=13%) and aggressive/lethal prostate cancer (OR=1.08, 95% CI=0.99, 1.19; I²=40%). Sensitivity analyses restricted to studies with birthweight extracted from medical records demonstrated stronger positive associations with total (OR=1.11, 95% CI=1.03, 1.19; I²=0%) and aggressive/lethal (OR=1.37, 95% CI=1.09, 1.74; I²=0%) prostate cancer. These studies heavily overlapped with those based in Nordic countries.

Conclusions:

This study provides evidence that heavier birthweight may be associated with modest increased risks of total and aggressive/lethal prostate cancer, which supports the hypothesis that intrauterine exposures may be related to subsequent prostate cancer risks.

Male Pattern Baldness in Relation to Prostate Cancer-Specific Mortality: A Prospective Analysis in the NHANES I Epidemiologic Follow-up Study

We used male pattern baldness as a proxy for long-term androgen exposure and investigated the association of dermatologist-assessed hair loss with prostate cancer-specific mortality in the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study. From the baseline survey (1971-1974), we included 4,316 men who were 25-74 years of age and had no prior cancer diagnosis. We estimated hazard ratios and used Cox proportional hazards regressions with age as the time metric and baseline hazard stratified by baseline age. A hybrid framework was used to account for stratification and clustering of the sample design, with adjustment for the variables used to calculate sample weights. During follow-up (median, 21 years), 3,284 deaths occurred; prostate cancer was the underlying cause of 107. In multivariable models, compared with no balding, any baldness was associated with a 56% higher risk of fatal prostate cancer (hazard ratio = 1.56; 95% confidence interval: 1.02, 2.37), and moderate balding specifically was associated with an 83% higher risk (hazard ratio = 1.83; 95% confidence interval: 1.15, 2.92). Conversely, patterned hair loss was not statistically significantly associated with all-cause mortality. Our analysis suggests that patterned hair loss is associated with a higher risk of fatal prostate cancer and supports the hypothesis of overlapping pathophysiological mechanisms.

Obesity and Prostate Cancer

Prostate cancer is a complex, heterogeneous disease. Factors related to detection, particularly PSA screening, further increase heterogeneity in the manifestation of the disease. It is thus not possible to provide a simple summary of the relationship between obesity and prostate cancer. Findings on obesity, often defined using body mass index (BMI), and total prostate cancer risk have been mixed; however, obesity is relatively consistently associated with a higher risk of aggressive prostate cancer, with aggressiveness defined in various ways (e.g., advanced stage, fatal, poorer prognosis in men with prostate cancer). Many methodologic issues (e.g., influence of PSA screening, detection bias and treatment) need to be thoroughly considered in both existing and future etiologic and prognostic research. Biological mechanisms supporting the link are under investigation, but may involve insulin and IGF axis, sex steroid hormones and alterations in metabolism. Some promising data suggest that molecular sub-types of prostate cancer may offer insights into etiology, but further study is required. A full evaluation of body fatness and weight change over the life course would not only provide insights to the underlying mechanisms but also allow more effective interventions.

The effects of height and BMI on prostate cancer incidence and mortality: a Mendelian randomization study in 20,848 cases and 20,214 controls from the PRACTICAL consortium

BACKGROUND

Epidemiological studies suggest a potential role for obesity and determinants of adult stature in prostate cancer risk and mortality, but the relationships described in the literature are complex. To address uncertainty over the causal nature of previous observational findings, we investigated associations of height- and adiposity-related genetic variants with prostate cancer risk and mortality.

METHODS

We conducted a case-control study based on 20,848 prostate cancers and 20,214 controls of European ancestry from 22 studies in the PRACTICAL consortium. We constructed genetic risk scores that summed each man's number of height and BMI increasing alleles across multiple single nucleotide polymorphisms robustly associated with each phenotype from published genome-wide association studies.

RESULTS

The genetic risk scores explained 6.31 and 1.46% of the variability in height and BMI, respectively. There was only weak evidence that genetic variants previously associated with increased BMI were associated with a lower prostate cancer risk (odds ratio per standard deviation increase in BMI genetic score 0.98; 95% CI 0.96, 1.00; p = 0.07). Genetic variants associated with increased height were not associated with prostate cancer incidence (OR 0.99; 95% CI 0.97, 1.01; p = 0.23), but were associated with an increase (OR 1.13; 95 % CI 1.08, 1.20) in prostate cancer mortality among low-grade disease (p heterogeneity, low vs. high grade <0.001). Genetic variants associated with increased BMI were associated with an increase (OR 1.08; 95 % CI 1.03, 1.14) in all-cause mortality among men with low-grade disease (p heterogeneity = 0.03).

CONCLUSIONS

We found little evidence of a substantial effect of genetically elevated height or BMI on prostate cancer risk, suggesting that previously reported observational associations may reflect common environmental determinants of height or BMI and prostate cancer risk. Genetically elevated height and BMI were associated with increased mortality (prostate cancer-specific and all-cause, respectively) in men with low-grade disease, a potentially informative but novel finding that requires replication.