Obesity, body composition, and prostate cancer

Overlapping and Distinct Physical and Biological Phenotypes in Pure Frailty and Obese Frailty

BACKGROUND

Pure frailty and obese frailty are common types of frailty syndrome. However, the overlapping and distinct characteristics between pure frailty and obese frailty remain unclear. This study aims to reveal the overlapping/distinct physical and biological phenotypes of pure frailty and obese frailty, providing theoretical support for their prevention, diagnosis, and treatment.

METHOD

Mice were fed either a normal or high-fat diet and assessed at 20 months of age. They were assigned to one of the four groups: control, obesity, pure frailty, and obese frailty. Grip strength, walking speed, physical activity, endurance, and body weight were measured to determine pure frailty and obese frailty. Physical and biological phenotypes were assessed.

RESULTS

Distinct physical phenotypes were observed between pure frailty and obese frailty in terms of body weight, lean mass, fat mass, fat mass in tissue, grip strength, endurance, and physical activity, while walking speed overlapped. In biological phenotypes, levels of Smad2/3, FoxO3a, P62, LAMP-2, and cathepsin L expression were distinct, while AKT, p-AKT, mTOR, p-mTOR, p-Smad2/3, p-FoxO3a, Beclin-1, ATG7, and LC3 overlapped.

CONCLUSION

Distinct physical phenotypes observed in obese frailty are primarily attributable to the effect of obesity, with further impairment of muscle function resulting from the combined effects of frailty syndromes and obesity. Pure frailty and obese frailty share overlapping biological phenotypes, particularly in the regulation of muscle protein synthesis. Moreover, the interaction between obesity and frailty syndromes gives rise to both overlapping and distinct biological phenotypes, especially in the regulation of specific degradation signaling proteins.

The association between neighborhood obesogenic factors and prostate cancer risk and mortality: the Southern Community Cohort Study

Background

Prostate cancer is one of the leading causes of cancer-related mortality among men in the United States. We examined the role of neighborhood obesogenic attributes on prostate cancer risk and mortality in the Southern Community Cohort Study (SCCS).

Methods

From the total of 34,166 SCCS male participants, 28,356 were included in the analysis. We assessed the relationship between neighborhood obesogenic factors [neighborhood socioeconomic status (nSES) and neighborhood obesogenic environment indices including the restaurant environment index, the retail food environment index, parks, recreational facilities, and businesses] and prostate cancer risk and mortality by controlling for individual-level factors using a multivariable Cox proportional hazards model. We further stratified prostate cancer risk analysis by race and body mass index (BMI).

Results

Median follow-up time was 133 months [interquartile range (IQR): 103, 152], and the mean age was 51.62 (SD: ± 8.42) years. There were 1,524 (5.37%) prostate cancer diagnoses and 98 (6.43%) prostate cancer deaths during follow-up. Compared to participants residing in the wealthiest quintile, those residing in the poorest quintile had a higher risk of prostate cancer (aHR = 1.32, 95% CI 1.12-1.57, p = 0.001), particularly among non-obese men with a BMI < 30 (aHR = 1.46, 95% CI 1.07-1.98, p = 0.016). The restaurant environment index was associated with a higher prostate cancer risk in overweight (BMI ≥ 25) White men (aHR = 3.37, 95% CI 1.04-10.94, p = 0.043, quintile 1 vs. None). Obese Black individuals without any neighborhood recreational facilities had a 42% higher risk (aHR = 1.42, 95% CI 1.04-1.94, p = 0.026) compared to those with any access. Compared to residents in the wealthiest quintile and most walkable area, those residing within the poorest quintile (aHR = 3.43, 95% CI 1.54-7.64, p = 0.003) or the least walkable area (aHR = 3.45, 95% CI 1.22-9.78, p = 0.020) had a higher risk of prostate cancer death.

Conclusion

Living in a lower-nSES area was associated with a higher prostate cancer risk, particularly among Black men. Restaurant and retail food environment indices were also associated with a higher prostate cancer risk, with stronger associations within overweight White individuals. Finally, residing in a low-SES neighborhood or the least walkable areas were associated with a higher risk of prostate cancer mortality.

The association between neighborhood obesogenic factors and prostate cancer risk and mortality: the Southern Community Cohort Study

Background

Prostate cancer is one of the leading causes of cancer-related mortality among men in the United States. We examined the role of neighborhood obesogenic attributes on prostate cancer risk and mortality in the Southern Community Cohort Study (SCCS).

Methods

From the total of 34,166 SCCS male participants, 28,356 were included in the analysis. We assessed the relationship between neighborhood obesogenic factors [neighborhood socioeconomic status (nSES) and neighborhood obesogenic environment indices including the restaurant environment index, the retail food environment index, parks, recreational facilities, and businesses] and prostate cancer risk and mortality by controlling for individual-level factors using a multivariable Cox proportional hazards model. We further stratified prostate cancer risk analysis by race and body mass index (BMI).

Results

Median follow-up time was 133 months [interquartile range (IQR): 103, 152], and the mean age was 51.62 (SD: ± 8.42) years. There were 1,524 (5.37%) prostate cancer diagnoses and 98 (6.43%) prostate cancer deaths during follow-up. Compared to participants residing in the wealthiest quintile, those residing in the poorest quintile had a higher risk of prostate cancer (aHR = 1.32, 95% CI 1.12-1.57, p = 0.001), particularly among non-obese men with a BMI < 30 (aHR = 1.46, 95% CI 1.07-1.98, p = 0.016). The restaurant environment index was associated with a higher prostate cancer risk in overweight (BMI ≥ 25) White men (aHR = 3.37, 95% CI 1.04-10.94, p = 0.043, quintile 1 vs. None). Obese Black individuals without any neighborhood recreational facilities had a 42% higher risk (aHR = 1.42, 95% CI 1.04-1.94, p = 0.026) compared to those with any access. Compared to residents in the wealthiest quintile and most walkable area, those residing within the poorest quintile (aHR = 3.43, 95% CI 1.54-7.64, p = 0.003) or the least walkable area (aHR = 3.45, 95% CI 1.22-9.78, p = 0.020) had a higher risk of prostate cancer death.

Conclusion

Living in a lower-nSES area was associated with a higher prostate cancer risk, particularly among Black men. Restaurant and retail food environment indices were also associated with a higher prostate cancer risk, with stronger associations within overweight White individuals. Finally, residing in a low-SES neighborhood or the least walkable areas were associated with a higher risk of prostate cancer mortality.

Predicted lean body mass trajectories, and cancer risk and cancer-specific and all-cause mortality: A prospective cohort study

BACKGROUND

Although many studies have investigated the association between body composition, cancer risk and mortality, predicting these risks through a single body composition measurement undoubtedly increases the limitations of the study. Few studies have explored the association between the trajectory of changes in body composition and the risk of cancer and death. We aimed to explore the association of predicted lean mass trajectories with cancer risk, cancer-specific mortality and all-cause mortality.

METHODS

The participants in this study were all from the Kailuan cohort, a prospective, periodic, resurvey cohort study initiated in 2006. Latent mixture modelling was used to identify predicted lean mass trajectories for 2006-2010. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) of the Cox proportional hazard models were used to describe the association between predicted lean mass trajectories and cancer risk and cancer-specific and all-cause mortality during follow-up (2010-2021).

RESULTS

A total of 44 374 participants (average age, 53.01 ± 11.41 years, 78.99% men and 21.01% women) were enrolled in this study. Five distinct trajectories were identified: low-stable (n = 12 060), low-increasing (n = 8027), moderately stable-decreasing (n = 4725), moderately stable-increasing (n = 8053) and high-stable (n = 11 509). During the 11-year follow-up period, 2183 cancer events were recorded. After adjusting for age, predicted fat mass in 2010, sex, BMI, sedentary, physical activity, smoke, alcohol use, salt consumption, high-fat diet, high-sensitivity C-reactive protein, serum creatinine, family history of tumour, hypertension, diabetes mellitus, compared with the low-stable group, participants in the low-increasing group (HR = 0.851, 95% CI, 0.748-0.969), moderately stable-increasing group (HR = 0.803, 95% CI, 0.697-0.925) and high-stable group (HR = 0.770, 95% CI, 0.659-0.901) had a lower cancer risk, but not in the moderately stable-decreasing group (HR = 0.864, 95% CI, 0.735-1.015). Compared with the low-stable group, the risk of cancer-specific mortality was reduced by 25.4% (8.8-38.9%), 36.5% (20.3-49.4%) and 35.4% (17.9-49.2%), and the risk of all-cause mortality was reduced by 24.2% (16.9-30.8%), 37.0% (30.0-43.2%) and 47.4% (41.0-53.1%) in the low-increasing, moderately stable-increasing group and high-stable groups, respectively.

CONCLUSIONS

Predicted lean mass trajectories may be closely associated with cancer risk and cancer-specific and all-cause mortality. Regular monitoring of body composition is necessary.

Association between atherogenic lipids and GnRH agonists for prostate cancer in men with T2DM: a nationwide, population-based cohort study in Sweden

BACKGROUND

Gonadotropin-releasing hormone agonists (GnRH) used in prostate cancer (PCa) are associated with atherogenic dyslipidaemia. It can be assumed that GnRH need to be used with greater caution in men with type 2 diabetes mellitus (T2DM). This study investigated association of GnRH with atherogenic lipids (AL) in PCa men with T2DM.

METHODS

Two cohorts including 38,311 men with 11 years follow-up based on Swedish national registers were defined (PCa-Exposure cohort and GnRH-Exposure cohort). Based on European guidelines on cardiovascular diseases (CVD), primary outcomes were defined as: 1.0 mmol/L increase in AL and lipid-lowering therapy (LLT) intensification. We used Cox proportional-hazards models and Kaplan-Meier curves to assess the association.

RESULTS

There was an association between GnRH and increased AL (i.e., triglyceride, PCa-Exposure cohort: HR 1.77, 95% CI 1.48-2.10; GnRH-Exposure cohort: HR 1.88, 95% CI 1.38-2.57). There was also an association between PCa diagnosis and increased AL. In contrast, no association between LLT intensification and GnRH was found.

CONCLUSION

In this large population-based study, men with T2DM on GnRH for PCa had an increased risk of increased atherogenic lipids. These results highlight the need to closely monitor lipids and to be ready to intensify lipid-lowering therapy in men with T2DM on GnRH for PCa.

Circadian Rhythm Disruption as a Contributor to Racial Disparities in Prostate Cancer

In the United States, African American (AA) men have a 2.4 times higher mortality rate due to prostate cancer than White men. The multifactorial causes of the racial disparities in prostate cancer involve various social determinants of health, socioeconomic status, and access to healthcare. However, emerging evidence also suggests that circadian rhythm disruption (CRD) contributes to prostate cancer, and AA men may be more susceptible to developing CRDs. Circadian rhythms play a significant role in metabolism, hormone secretion, and sleep/wake cycles. Disruption in these circadian rhythms can be caused by airplane travel/jetlag, night shift work, exposure to light, and neighborhood noise levels, which can contribute to sleep disorders and chronic conditions such as obesity, diabetes, cardiovascular disease, and depression. The drivers of the racial disparities in CRD include night shift work, racial discrimination, elevated stress, and residing in poor neighborhoods characterized by high noise pollution. Given the increased vulnerability of AA men to CRDs, and the role that CRDs play in prostate cancer, elucidating the clock-related prostate cancer pathways and their behavior and environmental covariates may be critical to better understanding and reducing the racial disparities in prostate cancer.

Body Composition and Prostate Cancer Risk: A Systematic Review of Observational Studies

Body composition parameters are not captured by measures of body mass, which may explain inconsistent associations between body weight and prostate cancer (PC) risk. The objective of this systematic review was to characterize the association between fat mass (FM) and fat-free mass (FFM) parameters and PC risk. A search of PubMed, Embase, and Web of Science identified case-control and cohort studies that measured body composition in relation to PC risk. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Thirteen observational studies were included, of which 8 were case-control studies (n = 1572 cases, n = 1937 controls) and 5 were prospective cohort studies (n = 7854 incident cases with PC). The NOS score was 5.9 ± 1.1 for case-control studies and 8.4 ± 1.3 for cohort studies. The most common body composition technique was bioelectrical impedance analysis (n = 9 studies), followed by DXA (n = 2), computed tomography (n = 2), air displacement plethysmography (n = 1), and MRI (n = 1). No case-control studies reported differences in %FM between PC cases and controls and no consistent differences in FM or FFM (in kilograms) were observed. Two out of 5 cohort studies reported that higher %FM was associated with lower PC risk. Conversely, 3 cohort studies reported a greater risk of being diagnosed with advanced/aggressive PC with higher FM (expressed in kilograms, %FM, or fat distribution). Two out of 4 studies (both case-control and cohort) found that higher abdominal adipose tissue was associated with increased PC risk. In conclusion, although results were inconsistent, there is some evidence that FM may be negatively associated with total PC risk but positively associated with the risk of advanced/aggressive PC; modest evidence suggests that abdominal adipose tissue may increase the risk of PC. Future work should elucidate unique patterns of FM distribution and PC risk to triage men at risk for developing PC. This study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database as CRD42019133388.

Association of body composition with risk of overall and site-specific cancers: A population-based prospective cohort study

Although excess adiposity has been linked with various cancers, association between body composition and some cancers remains unclear, like lung and prostate cancers. We investigated associations of body composition with risk of overall cancer and major site-specific cancers in a prospective cohort of 454 079 cancer-free participants from UK-Biobank. Body composition was measured with bioimpedance analysis. We evaluated hazard ratio (HR) and 95% confidence interval (CI) with multivariate Cox linear and nonlinear models in men and women separately. We identified 27 794 cancers over 7.6 years of follow-up. Multivariable adjusted models including fat-free mass (FFM) and fat mass (FM) showed that FFM was positively associated with overall cancer risk in men and women (HR 1.03, 95% CI 1.01-1.04 and 1.07, 1.04-1.10, respectively); while the association between FM and overall cancer disappeared after adjusting for FFM. FFM was associated with higher risks of obesity-related cancers combined, stomach (women only), malignant melanoma, postmenopausal breast, corpus uteri, prostate, kidney (men only), and blood cancers and lower risk of lung cancer. FM was associated with higher risks of obesity-related cancers combined, esophageal, colon, lung (men only), postmenopausal breast (at the lower end of FM range), and corpus uteri cancers and lower risks of rectal, malignant melanoma (women only), prostate and blood cancers. FFM and FM seemed to have different effects on cancer risk, and the effects varied substantially by cancer type, in both direction and size. Higher FM/FFM ratio was also associated with some cancers risk, and might be a useful predictor of cancer risk.

Body composition and risk of major gynecologic malignancies: Results from the UK Biobank prospective cohort

OBJECTIVE

To evaluate the association between body composition and subsequent risk of the major gynecologic malignancies.

METHODS

This is a prospective analysis of participants from the UK Biobank. We measured baseline body composition and confirmed cancer diagnosis through linkage to cancer and death registries. We evaluated hazard ratios (HRs) and confidence interval (CIs) with COX models adjusting for potential confounders.

RESULTS

We document 1430 cases of the top three gynecologic malignancies (uterine corpus cancer 847 cases, ovarian cancer 514 cases, and cervical cancer 69 cases) from 245,084 female participants (75,307 were premenopausal and 169,777 were postmenopausal). For premenopausal women, whole body fat-free mass (WBFFM) was associated with an increased risk of uterine corpus cancer (Adjusted HR per unit increase 1.04, 95% CI 1.02-1.06). For postmenopausal women, compared with the first quartile, the fourth quartile of WBFFM and whole body fat mass(WBFM) was associated with 2.16 (95% CI 1.49-3.13) times and 1.89 (95% CI 1.31-2.72) times of increased uterine corpus cancer risk, respectively. Regarding the distribution of body fat mass (FM)/fat-free mass (FFM), FFM distributed in the trunk was associate with increased uterine corpus cancer risk in premenopausal (HR 1.18,95% CI 1.07-1.31) and postmenopausal women (HR 1.13,95% CI 1.09-1.18). Meanwhile, FM/FFM distributed in the limbs present an U-shaped associations with uterine corpus cancer risk. We did not observe any association between aforementioned body composition indices with ovarian or cervical cancer.

CONCLUSION

FM is associated with an increased risk of uterine corpus cancer in postmenopausal women. Meanwhile, FFM is found to be a risk factor for uterine corpus cancer in both premenopausal and postmenopausal women. No association of body composition with ovarian or cervical cancer was observed.

Body shape and pants size as surrogate measures of obesity among males in epidemiologic studies

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Alternative anthropometric indicators reflect overall and abdominal obesity in males.

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Abdominal obesity is predicted using age, pants size, Stunkard’s silhouette & weight.

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Stunkard’s silhouette scale reflects well body mass index recently and in the past.

This study aimed at characterizing anthropometric indicators that can be used as alternatives to measurements for assessing overall obesity over adulthood and abdominal obesity among men. We used data from a population-based case-control study of prostate cancer conducted in Montreal, Canada in 2005–2012. It included men aged ≤ 75 years, 1872 of which were newly diagnosed with prostate cancer, and 1918 others randomly selected from the electoral list. In-person interviews elicited reports of height as well as of weight, pants size and Stunkard’s silhouette at 5 time points over adulthood, i.e., for the ages of 20, 40, 50 and 60 years, if applicable, and at the time of interview. Waist and hip circumferences were measured by interviewers following a validated protocol. Analyses were conducted on the overall sample of 3790 subjects, after having confirmed that results did not differ according to disease status. Stunkard’s silhouette scale proved to be an easy-to-administer tool that reflects well reported body mass index, either recently or decades in the past among adult males. It was discriminatory enough to classify individuals according to commonly-used obesity categories. We observed that a model including age, reported pants size, silhouette and weight can reasonably predict current abdominal obesity. In conclusion, alternative anthropometric indicators can serve as valuable means to assess overall and abdominal obesity when measurements cannot be envisaged in the context of epidemiological studies.

Muscle Characteristics Obtained Using Computed Tomography as Prognosticators in Patients with Castration-Resistant Prostate Cancer

Limited studies have investigated the correlation between body composition and prostate cancer outcomes. We analyzed the effect of muscle mass and quality on castration-resistant prostate cancer (CRPC) outcomes. Skeletal muscle index (SMI) and skeletal muscle attenuation (SMA) were measured for 411 patients at the L3 vertebral level using computed tomography at CRPC diagnosis and were dived to low and high groups at the value of median. Analysis of the skeletal phenotypes and age (<70 and >70 years) was performed to evaluate the effect of SMI and SMA. The median survival rates for patients with low and high SMI were 19 and 24 months (p = 0.015), and those with low and high SMAs were 15 and 26 months (p < 0.001), respectively. In the subgroup analysis by age, SMA was a significant prognosticator in both groups, while SMI was a significant prognosticator only in patients aged >70 years. Patients with low SMA + low SMI had the worst prognosis. Muscle characteristics seems to be a prognosticator in survival of CRPC patients and may be considered in treatment planning.

Does increased body mass index lead to elevated prostate cancer risk? It depends on waist circumference

Background

We examined the association between obesity and prostate cancer based on both body mass index (BMI) and waist circumference (WC) using the National Health Insurance System (NHIS) database for the entire male population of Korea.

Methods

A total of 1,917,430 men who underwent at least one health examination in 2009 without a previous diagnosis of any other cancer were tracked through December 2015. The hazard ratio (HR) and 95% confidence interval (CI) value for the association between prostate cancer and obesity were analyzed using multiple Cox regression model. Since there was a statistically significant interaction between WC and BMI, a multiple HR for prostate cancer was estimated with stratifying both WC and BMI to control the interaction between WC and BMI.

Results

Without considering WC as an adjustment factor, very weak association between BMI and prostate cancer development risk was observed. When WC was considered as an adjustment factor, no significant change in the HRs for prostate cancer development beyond the reference BMI was observed in the group with WC < 85 cm in the multivariable-adjusted models. However, in the group with WC ≥ 85 cm, the HRs for prostate cancer increased as the BMI increased beyond the reference BMI. In addition, there was a discrepancy in the trend of prostate cancer development according to BMI among the groups with different categories for WC.

Conclusion

In groups with abdominal obesity, a significant linear relationship was observed between increasing BMI and prostate cancer risk. Higher the WC category, the stronger was the association with BMI, signifying that the association of BMI with risk of prostate cancer development depends on abdominal obesity.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Body fat distribution on computed tomography imaging and prostate cancer risk and mortality in the AGES-Reykjavik study

BACKGROUND

The World Cancer Research Fund classifies as "strong evidence" the link between obesity and the risk of advanced prostate cancer. In light of the different hormonal profiles associated with where adipose is stored, this study investigated the role of objectively measured body fat distribution and the risk of clinically relevant prostate cancer.

METHODS

This was a prospective study of 1832 men in the Age, Gene/Environment Susceptibility-Reykjavik study. From 2002 to 2006, participants underwent baseline computed tomography imaging of fat deposition, bioelectric impedance analysis, and measurement of body mass index (BMI) and waist circumference. Men were followed through linkage with nationwide cancer registries for the incidence of total (n = 172), high-grade (Gleason grade ≥8; n = 43), advanced (≥cT3b/N1/M1 at diagnosis or fatal prostate cancer over follow-up; n = 41), and fatal prostate cancer (n = 31) through 2015. Cox regression was used to evaluate the association between adiposity measures and prostate cancer outcomes.

RESULTS

Among all men, visceral fat (hazard ratio [HR], 1.31 per 1-standard deviation [SD] increase; 95% confidence interval [CI], 1.00-1.72) and thigh subcutaneous fat (HR, 1.37 per 1-SD increase; 95% CI, 1.00-1.88) were associated with risk of advanced and fatal disease, respectively. Among men who were leaner based on BMI, visceral fat was associated with both advanced and fatal disease. BMI and waist circumference were associated with a higher risk of advanced and fatal disease. No adiposity measures were associated with total or high-grade disease.

CONCLUSIONS

Specific fat depots as well as BMI and waist circumference were associated with the risk of aggressive prostate cancer, which may help to elucidate underlying mechanisms and target intervention strategies.

Statin use linked with a decrease in the conversion from high-grade prostatic intraepithelial neoplasia (HGPIN) to prostate cancer

The roles of obesity, metabolic dysregulation and systemic inflammation to advance prostate carcinogenesis are unclear. This study investigates metabolic and inflammatory factors in the transition from high-grade prostatic intraepithelial neoplasia (HGPIN) to prostate cancer (PC). We prospectively followed 160 men diagnosed with HGPIN at biopsy and therefore at high-risk and clinically monitored for PC. Analyses investigated body mass index (BMI), waist circumference, waist-hip ratio (WHR), height, fat mass, lean mass percent body fat, NSAIDs, statins, metformin, diabetes, hypertension, hypercholesterolemia representing metabolic dysregulation on the risk of a PC diagnosis during follow-up. Systemic inflammation was estimated through measurement of 13 plasma cytokine levels. Statin use was significantly linked with overall PC at follow-up [odds ratio (OR) = 0.45, (0.23, 0.91), P = 0.03], with a somewhat stronger link with high-grade [OR = 0.39, (0.15, 1.04), P = 0.06] PC compared with low-grade PC [OR = 0.50, (0.23, 1.12), P = 0.09]. Non-statin cholesterol-lowering medications, BMI, WHR, diabetes, hypertension and percent body fat were not significantly associated with PC. Although blood IL-12p70, IL-2 and IL-1β levels were significantly lower among statin users, inflammatory markers were not significantly linked with PC and did not explain the observed relationship between statins and lower PC risk. In summary, this prospective study of HGPIN patients at high risk for PC finds that statin use was significantly associated with reduced risk of PC detection at follow-up. Systemic markers of inflammation did not mediate this association, suggesting that statins affect PC progression through alternative pathways.

Abdominal obesity and prostate cancer risk: epidemiological evidence from the EPICAP study

Obesity is associated with an increased risk of several cancers, but inconsistent results have been observed between body mass index (BMI) and prostate cancer (PCa) risk. However, some associations have been reported with other indicators such as waist circumference (WC) and waist-hip ratio (WHR). We investigated the role of anthropometric indicators in PCa risk based on data from the Epidemiological study of Prostate Cancer (EPICAP).

EPICAP is a population-based case-control study that included 819 incident PCa in 2012–2013 and 879 controls frequency matched by age. Anthropometric indicators (weight, height, WC, and hip circumference) have been measured at interview. Logistic regression models were used to assess odds ratios (ORs) for the associations between anthropometric indicators (BMI, WC and WHR) and PCa risk.

We observed a slight, but not significant increased risk of PCa for men with a WC > 94 cm (OR 1.20, 95% CI 0.92–1.56) and for men with a WHR ≥ 0.95 (OR 1.30, 95% CI 1.00–1.70 between 0.95 and 1.00, OR 1.25, 95% CI 0.96–1.61 above 1.00). Associations were more pronounced after adjustment and stratification for BMI and in men with aggressive PCa.

Our results suggest that abdominal obesity may be associated with an increased risk of PCa, especially aggressive PCa.

Diet, Physical Activity, and Body Weight in Cancer Survivorship

Diet, physical activity, and body weight have been shown to play an important role in cancer survivorship. The impact of each of these lifestyle factors differs slightly among cancer types, and adherence to recommended diet and physical activity guidelines has been associated with positive outcomes, including decrease in the risk of cancer recurrence and improvement of quality of life. Although there are compelling data that appropriate diet, physical activity, and body weight have beneficial effects in cancer survivorship, additional trials are needed to understand the relationship.

Is Body Mass Index the Best Adiposity Measure for Prostate Cancer Risk? Results From a Veterans Affairs Biopsy Cohort

OBJECTIVE

To test multiple adiposity measures and prostate cancer (PC) risk in men undergoing prostate biopsy. We hypothesized that body mass index (BMI), body fat, and waist circumference would be highly correlated, and all would be associated with aggressive PC, but not overall risk.

SUBJECTS AND METHODS

A case (483)-control (496) study among men undergoing prostate biopsy from 2007 to 2016 was conducted at the Durham Veterans Affairs Medical Center. Anthropometric and self-reported measurements were taken. Percent body fat was measured. Associations between adiposity measures and PC risk and high-grade PC (Gleason ≥7) were examined using logistic regression.

RESULTS

BMI, percent body fat, and waist circumference were highly correlated (ρ ≥ .79) (P < .001). On multivariable analysis, BMI (P = .011) was associated with overall PC risk, but percent body fat (P = .16) and waist circumference (P = .19) were not. However, all adiposity measurements were associated with high-grade disease (P < .001). We found a strong relationship between self-reported and measured weight (ρ = .97) and height (ρ = .92).

CONCLUSION

BMI, body fat, and waist circumference were all highly correlated and associated with aggressive PC. This study supports the idea that higher adiposity is selectively associated with high-grade PC and reinforces the continued use of self-reported BMI as a measure of obesity in epidemiologic studies of PC.

Obesity, age, ethnicity, and clinical features of prostate cancer patients

Approximately 36.5% of the U.S. adults (≥ 20 years old) are obese. Obesity has been associated with type 2 diabetes mellitus, cardiovascular disease, stroke, and several types of cancer. The present study included 1788 prostate cancer patients who were treated with radical prostatectomy at the Ochsner Health System, New Orleans, Louisiana, from January, 2001 to March, 2016. The patient's medical records were retrospectively reviewed. Body mass index (BMI), age, ethnicity (Caucasians versus African Americans), clinical stage, Gleason score, and prostate-specific antigen (PSA) levels were retrieved. The relative risk of the patients was stratified into low risk and high risk groups. Associative analyses found that BMI was associated with age, clinical stage, Gleason score, but not ethnicity, PSA levels, or the relative risk in this cohort. Age was associated with ethnicity, clinical stage, Gleason score, and PSA levels, as well as the relative risk. Ethnicity was associated with Gleason score and PSA levels as well as the relative risk, but not clinical stage. These findings suggest that obesity is associated with advanced prostate cancer with stage T3 or Gleason score ≥ 7 diseases, and age and ethnicity are important factors that are associated with the clinical features of prostate cancer patients.

Correlations of Metabolic Components with Prostate Volume in Middle-Aged Men Receiving Health Check-Up

OBJECTIVES

To investigate the impact of metabolic components and body composition indices on prostate volume (PV) in a population of middle-aged men receiving health check-ups.

METHODS

Six hundred and sixteen men receiving health assessments were stratified to large and small prostates based on the cut-off of median PV. Their demographic data, health history, and international prostate symptoms scores (IPSS) were collected. Metabolic components and body composition indices were compared between subjects with large and small prostates. Moreover, the correlations between these parameters and PV were analyzed by multivariate logistic regression.

RESULTS

The median PV was 27 mL and mean age was 54.8 years. Subjects with large PV were older (56.5 vs. 52.7 years) and had higher serum prostate specific antigen (PSA) level (1.73 vs. 0.96 ng/mL), higher IPSS score (8.37 vs. 6.16), and higher body fat, body mass, and waist circumference (all p<0.05). In multivariate analysis, age (OR, 2.45; 95%CI, 1.74-3.45), serum PSA (OR, 2.75; 95%CI, 1.96-3.86), waist circumference (OR, 1.45; 95%CI, 1.02-2.07), fatness (OR, 1.47; 95%CI, 1.04-2.09), and body fat mass (OR, 1.43; 95%CI, 1.00-2.03) were significantly correlated with PV of study subjects. In subgroup analysis, raised waist circumference (OR, 1.89; 95%CI, 1.00-3.59) was the independent predictor of PV in subjects with bothersome lower urinary tract symptoms.

CONCLUSIONS

Several metabolic components and body composition indices are significantly associated with PV of middle-aged men, including raised waist circumference, fatness, and body fat mass. Raised waist circumference is the only independent predictor of PV in middle-aged men with bothersome LUTS.

Assessment of anticancer-treatment outcome in patients with metastatic castration-resistant prostate cancer-going beyond PSA and imaging, a systematic literature review

BACKGROUND

In the past years, there has been significant progress in anticancer drug development for patients with metastatic castration-resistant prostate cancer (CRPC). However, the current instruments to assess clinical treatment response have limitations and may not sufficiently reflect patient benefit. Our objective was to systematically identify tools to evaluate both patient benefit and clinical anticancer-treatment response as basis for an international consensus process and development of a specific pragmatic instrument for men with CRPC.

METHODS

PubMed, Embase and CINAHL were searched to identify currently available tools to assess anticancer-treatment benefit, other than standard imaging procedures and prostate-specific antigen measurements, namely quality of life (QoL), detailed pain assessment, physical function and objective measures of other complex cancer-related syndromes in patients with CRPC. Additionally, all CRPC phase III trials published in the last 5 years were reviewed as well as studies using physical function tools in a general cancer population. The PRIMSA statement was followed for the systematic review process.

RESULTS

The search generated 1096 hits, 185 full-text papers were screened and finally 73 publications were included. Additional 89 publications were included by hand-search. We identified a total of 98 tools used in CRPC trials and grouped these into three categories: 22 tools assessing QoL domains and subgroups, 47 tools for pain assessment and 29 tools for objective measures, mainly physical function and assessment of skeletal disease burden.

CONCLUSION

A wide variety of assessment tools and also efforts to standardize and harmonize patient-reported outcomes and pain assessment were identified. However, the specific needs of the increasing CRPC population living longer with their incurable cancer are insufficiently captured and objective physical outcome measures are under-represented. In the age of new anticancer drug targets and principles, new methods to monitor patient relevant outcomes of antineoplastic therapy are of utmost importance.

Genetic Determinants of Metabolism and Benign Prostate Enlargement: Associations with Prostate Volume

Prostate enlargement leading to clinical benign prostatic hyperplasia (BPH) is associated with metabolic dysregulation and obesity. The genetic basis of this association is unclear. Our objective was to evaluate whether single nucleotide polymorphisms (SNPs) previously associated with metabolic disorders are also associated with prostate volume (PV). Participants included 876 men referred for prostate biopsy and found to be prostate cancer free. PV was measured by transrectal ultrasound. Samples were genotyped using the Illumina Cardio-MetaboChip platform. Multivariable adjusted linear regression models were used to evaluate SNPs (additive coding) in relation to natural-log transformed (log) PV. We compared SNP-PV results from biopsy-negative men to 442 men with low-grade prostate cancer with similar levels of obesity and PV. Beta-coefficients from the discovery and replication samples were then aggregated with fixed effects inverse variance weighted meta-analysis. SNP rs11736129 (near the pseudo-gene LOC100131429) was significantly associated with log-PV (beta: 0.16, p-value 1.16x10^-8) after adjusting for multiple testing. Other noteworthy SNPs that were nominally associated (p-value < 1x10^-4) with log-PV included rs9583484 (intronic SNP in COL4A2), rs10146527 (intronic SNP in NRXN3), rs9909466 (SNP near RPL32P31), and rs2241606 (synonymous SNP in SLC12A7). We found several SNPs in metabolic loci associated with PV. Further studies are needed to confirm our results and elucidate the mechanism between these genetic loci, PV, and clinical BPH.

Lifestyle Factors in Cancer Survivorship: Where We Are and Where We Are Headed

Advances in early detection and curative therapies have led to an increased number of cancer survivors over the last twenty years. With this population comes the need to evaluate the late and long term effects of cancer treatment and develop recommendations about how to optimally care for these survivors. Lifestyle factors (diet, body weight, physical activity, and smoking) have been linked to a higher risk of many medical comorbidities (cardiovascular, metabolic, etc.). There is increasing evidence linking these factors to the risk of developing cancer and likely cancer-related outcomes. This link has been studied extensively in common cancers like breast, colon, prostate, and lung cancers through observational studies and is now being prospectively evaluated in interventional studies. Realizing that survivors are highly motivated to improve their overall health after a diagnosis of cancer, healthy lifestyle recommendations from oncology providers can serve as a strong tool to motivate survivors to adopt health behavior changes. Our article aims to review the evidence that links lifestyle factors to cancer outcomes and provides clinical recommendations for cancer survivors.

Adipocyte secreted factors enhance aggressiveness of prostate carcinoma cells

Obesity has been associated with increased incidence and risk of mortality of prostate cancer. One of the proposed mechanisms underlying this risk association is the change in adipokines expression that could promote the development and progression of the prostate tumor cells. The main goal of this study was to evaluate the effect of preadipocyte and adipocyte secretome in the proliferation, migration and invasion of androgen independent prostate carcinoma cells (RM1) and to assess cell proliferation in the presence of the adiposity signals leptin and insulin. RM1 cells were co-cultured in with preadipocytes, adipocytes or cultured in their respective conditioned medium. Cell proliferation was assessed by flow cytometry and XTT viability test. Cell migration was evaluated using a wound healing injury assay of RM1 cells cultured with conditioned media. Cellular invasion of RM1 cells co-cultured with adipocytes and preadipocytes was assessed using matrigel membranes. Preadipocyte conditioned medium was associated with a small increase in RM1 proliferation, while adipocytes conditioned media significantly increased RM1 cell proliferation (p<0.01). Adipocytes also significantly increased the RM1 cells proliferation in co-culture (p <0.01). Cell migration was higher in RM1 cells cultured with preadipocyte and adipocyte conditioned medium. RM1 cell invasion was significantly increased after co-culture with preadipocytes and adipocytes (p <0.05). Insulin also increased significantly the cell proliferation in contrast to leptin, which showed no effect. In conclusion, prostate carcinoma cells seem to be influenced by factors secreted by adipocytes that are able to increase their ability to proliferate, migrate and invade.

Prostate cancer incidence, clinical stage and survival in relation to obesity: a prospective cohort study in Denmark

There is no clear link between obesity and prostate cancer incidence but an association has been reported between obesity and fatal prostate cancer. We report on two prospective cohort analyses on (i) the incidence of prostate cancer in relation to obesity in a cohort of men with no previous cancer, and on (ii) the stage distribution and prostate cancer specific mortality in relation to obesity among men with prostate cancer. The "Diet, Cancer and Health" prospective cohort study was established in Denmark in 1993-1997 and accrued 26,944 men aged 50-64 years. Data were extracted on height, weight, body mass index (BMI), waist circumference and body fat percentage. Information on cancer incidence and deaths were obtained by record linkage with the Danish Cancer Register and the Danish Death Register. The incidence rate of prostate cancer was similar or slightly lower in obese men compared with nonobese men, but obese men tended to be diagnosed with more advanced prostate cancer. The proportion of Stage 3-4 cancers was 37% in the lowest BMI quartile and 48% in the highest (p = 0.006). Obese men with prostate cancer had higher prostate cancer specific mortality. The hazard ratio comparing the highest and the lowest quartiles of BMI was 1.48 (95% confidence interval: 1.06-2.05; p-value for trend: 0.002). The association was attenuated but not eliminated by statistical adjustment for stage, and the data are suggestive of a stage-independent causal pathway where prostate cancer in obese men has higher fatality, even in early-stage disease.

Personal and family history of cancer and the risk of Barrett's esophagus in men

The association between Barrett's esophagus (BE) and a personal or family history of cancer other than gastroesophageal remains unknown. To evaluate the effect of personal and family history of certain cancers and cancer treatments on the risk of BE, we analyzed data from a Veterans Affairs case-control study that included 264 men with definitive BE (cases) and 1486 men without BE (controls). Patients with history of esophageal or gastric cancer were excluded. Patients underwent elective esophagogastroduodenoscopy or a study esophagogastroduodenoscopy concurrently with screening colonoscopy to determine BE status. Personal and family history of several types of cancer was obtained from self-reported questionnaires, supplemented and verified by electronic medical-record reviews. We estimated the association between personal and family history of cancer or radiation/chemotherapy, and BE. Personal history of oropharyngeal cancer (1.5% vs. 0.4%) or prostate cancer (7.2% vs. 4.4%) was more frequently present in cases than controls. The association between BE and prostate cancer persisted in multivariable analyses (adjusted odds ratio 1.90; 95% confidence interval 1.07-3.38, P = 0.028) while that with oropharyngeal cancer (adjusted odds ratio 3.63; 95% confidence interval 0.92-14.29, P = 0.066) was attenuated after adjusting for retained covariates of age, race, gastroesophageal reflux disease, hiatal hernia, and proton pump inhibitor use. Within the subset of patients with cancer, prior treatment with radiation or chemotherapy was not associated with BE. There were no significant differences between cases and controls in the proportions of subjects with several specific malignancies in first- or second-degree relatives. In conclusion, the risk of BE in men may be elevated with prior personal history of oropharyngeal or prostate cancer. However, prior cancer treatments and family history of cancer were not associated with increased risk of BE. Further studies are needed to elucidate if there is a causative relationship or shared risk factors between prostate cancer and BE.

Obesity promotes aerobic glycolysis in prostate cancer cells

Obesity is the leading preventable comorbidity associated with increased prostate cancer-related recurrence and mortality. Epidemiological and clinical studies indicate that a body mass index >30 is associated with increased oxidative DNA damage within the prostate gland and increased prostate cancer-related mortality. Here we provide evidence that obesity promotes worse clinical outcome through induction of metabolic abnormalities known to promote genotoxic stress. We have previously reported that blood serum derived from obese mice may enhance the proliferative and invasive potential of human prostate cancer cell lines ex vivo. Here we show that a 1-h exposure of LNCaP or PacMetUT1 prostate cancer cell lines and nonmalignant RWPE-1 prostate epithelial cells to 2% serum from obese mice induces markers of aerobic glycolysis relative to those exposed to serum from nonobese mice. This metabolic change was correlated with accumulation of reactive oxygen species (ROS) and increased frequency of DNA double-strand breaks. Interestingly, N-tert-Butylhydroxylamine, an antioxidant, significantly suppressed markers of aerobic glycolysis in the cells exposed to the blood serum of obese mice, suggesting that ROS contributes to a metabolic shift toward aerobic glycolysis. Here we describe obesity-induced changes in key metabolic markers that impact prostate cancer cell progression and explore the role of antioxidants in ameliorating these effects.

Obesity affects the biopsy-mediated detection of prostate cancer, particularly high-grade prostate cancer: a dose-response meta-analysis of 29,464 patients

BACKGROUND AND OBJECTIVES

In previous studies, obesity (measured according to the body mass index) has correlated inconsistently with the risk of biopsy-measured prostate cancer, and specifically high-grade prostate cancer. This meta-analysis aimed to clarify these correlations.

METHODS

A comprehensive literature search of the MEDLINE and EMBASE databases was conducted for relevant studies published through January 2014. The pooled estimates of odds ratios (OR) and confidence intervals (CI) were computed, and the meta-analysis was performed with the STATA software according to a random effects approach.

RESULTS

A total of 11 studies that included 29,464 individuals were identified. A 5-kg/m2 increase in body mass index was associated with a 15% (OR, 1.15; 95% CI, 0.98-1.34) higher risk of prostate cancer detection and a 37% (OR, 1.37; 95% CI, 1.19-1.57) higher risk of high-grade prostate cancer detection at biopsy. There were no differences among the results of studies conducted in the USA, Europe or Asia. We also found that studies that had adjusted for prostate-specific antigen levels, digital rectal examination results, and prostate volumes obtained positive significant outcomes (OR, 1.27; 95% CI, 1.12-1.44), whereas studies that did not adjust for the above-mentioned confounding variables obtained negative results (OR, 0.92; 95% CI, 0.68-1.25). Moreover, the positive correlation between body mass index and the detection of both prostate cancer and high-grade diseases tended to be stronger as the number of biopsy cores increased.

CONCLUSION

The present meta-analysis demonstrated that a high body mass index correlated positively with prostate cancer detection, especially high-grade prostate cancer detection. The adoption of a modified and possibly more aggressive biopsy strategy was suggested for obese populations.

Patient-centered perspectives on the access to educational opportunities specific to lifestyle modification in men at risk for primary or secondary prostate cancer

Educating men at risk for primary or secondary prostate cancer on lifestyle modification may help prevent the development of the disease, reduce the risk of recurrence in those treated for cancer, and slow the progression of active disease. To date, substantial literature on male patient attitudes towards risk modification does not exist. In this project, we evaluate the attitudes and educational needs of men at high-risk for primary or secondary prostate cancer to assess the need for a dedicated clinic focused on education and prevention. Two clinic nurses administered surveys to 76 male patients seen at the University Kansas Cancer Center (KUCC) and Urology clinics. Survey responses showed the patients' perspectives and desire for more support and education regarding late effects of treatment, management of risk, and lifestyle modification. Findings from this survey inspired the establishment of the Burns & McDonnell High-Risk Prostate Cancer Prevention Program at KUCC.

Exogenous fatty acid binding protein 4 promotes human prostate cancer cell progression

Epidemiologic studies have found that obesity is associated with malignant grade and mortality in prostate cancer. Several adipokines have been implicated as putative mediating factors between obesity and prostate cancer. Fatty acid binding protein 4 (FABP4), a member of the cytoplasmic fatty acid binding protein multigene family, was recently identified as a novel adipokine. Although FABP4 is released from adipocytes and mean circulating concentrations of FABP4 are linked with obesity, effects of exogenous FABP4 on prostate cancer progression are unclear. In this study, we examined the effects of exogenous FABP4 on human prostate cancer cell progression. FABP4 treatment promoted serum-induced prostate cancer cell invasion in vitro. Furthermore, oleic acid promoted prostate cancer cell invasion only if FABP4 was present in the medium. These promoting effects were reduced by FABP4 inhibitor, which inhibits FABP4 binding to fatty acids. Immunostaining for FABP4 showed that exogenous FABP4 was taken up into DU145 cells in three-dimensional culture. In mice, treatment with FABP4 inhibitor reduced the subcutaneous growth and lung metastasis of prostate cancer cells. Immunohistochemical analysis showed that the number of apoptotic cells, positive for cleaved caspase-3 and cleaved PARP, was increased in subcutaneous tumors of FABP4 inhibitor-treated mice, as compared with control mice. These results suggest that exogenous FABP4 might promote human prostate cancer cell progression by binding with fatty acids. Additionally, exogenous FABP4 activated the PI3K/Akt pathway, independently of binding to fatty acids. Thus, FABP4 might be a key molecule to understand the mechanisms underlying the obesity-prostate cancer progression link.

Longitudinal trends in prostate cancer incidence, mortality, and survival of patients from two Shanghai city districts: a retrospective population-based cohort study, 2000-2009

Background

Prostate cancer is the fifth most common cancer affecting men of all ages in China, but robust surveillance data on its occurrence and outcome is lacking. The specific objective of this retrospective study was to analyze the longitudinal trends of prostate cancer incidence, mortality, and survival in Shanghai from 2000 to 2009.

Methods

A retrospective population-based cohort study was performed using data from a central district (Putuo) and a suburban district (Jiading) of Shanghai. Records of all prostate cancer cases reported to the Shanghai Cancer Registry from 2000 to 2009 for the two districts were reviewed. Prostate cancer outcomes were ascertained by matching cases with individual mortality data (up to 2010) from the National Death Register. The Cox proportional hazards model was used to analyze factors associated with prostate cancer survival.

Results

A total of 1022 prostate cancer cases were diagnosed from 2000 to 2009. The average age of patients was 75 years. A rapid increase in incidence occurred during the study period. Compared with the year 2000, 2009 incidence was 3.28 times higher in Putuo and 5.33 times higher in Jiading. Prostate cancer mortality declined from 4.45 per 10⁵ individuals per year in 2000 to 1.94 per 10⁵ in 2009 in Putuo and from 5.45 per 10⁵ to 3.5 per 10⁵ in Jiading during the same period. One-year and 5-year prostate cancer survival rates were 95% and 56% in Putuo, and 88% and 51% in Jiading, respectively. Staging of disease, Karnofsky Performance Scale Index, and selection of chemotherapy were three independent factors influencing the survival of prostate cancer patients.

Conclusions

The prostate cancer incidence increased rapidly from 2000 to 2009, and prostate cancer survival rates decreased in urban and suburban Chinese populations. Early detection and prompt prostate cancer treatment is important for improving health and for increasing survival rates of the Shanghai male population.

Dietary carrot consumption and the risk of prostate cancer

PURPOSE

Previous studies regarding the association between carrot intake and prostate cancer risk have reported inconsistent results. We conducted a meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship.

METHOD

A systematic literature search of papers published in August 2013 was conducted using PubMed, EMBASE, Scopus, Web of Science, the Cochrane register, and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles were screened. The summary risk estimates with 95% confidence intervals (CIs) for the highest versus the lowest intake of carrots were calculated. A dose-response meta-analysis was also conducted for the studies reporting categorical risk estimates for a series of exposure levels.

RESULTS

We found a significantly decreased risk of prostate cancer associated with the intake of carrots (odds ratio 0.82, 95% CI 0.70-0.97). In addition, the dose-response meta-analysis indicated that for each serving per week, or 10 g per day increment of carrot intake, the risk estimate of prostate cancer was 0.95 (0.90-0.99) or 0.96 (0.94-0.99). There was no evidence of significant publication bias based on Begg's funnel plot (P = 1.000) or Egger's test (P = 0.804).

CONCLUSION

Carrot intake might be inversely associated with prostate cancer risk. Because of the limited number of cohort studies and substantial heterogeneity observed between studies in this meta-analysis, further well-designed prospective studies are warranted to confirm the findings from our study.

Lifetime body size and prostate cancer risk in a population-based case-control study in Sweden

PURPOSE

The role of body size in prostate cancer etiology is unclear and potentially varies by age and disease subtype. We investigated whether body size in childhood and adulthood, including adult weight change, is related to total, low-intermediate-risk, high-risk, and fatal prostate cancer.

METHODS

We used data on 1,499 incident prostate cancer cases and 1,118 population controls in Sweden. Body figure at age 10 was assessed by silhouette drawings. Adult body mass index (BMI) and weight change were based on self-reported height and weight between ages 20 and 70. We estimated odds ratios (ORs) with 95 % confidence intervals (CIs) by unconditional logistic regression.

RESULTS

Height was positively associated with prostate cancer. Overweight/obesity in childhood was associated with a 54 % increased risk of dying from prostate cancer compared to normal weight, whereas a 27 % lower risk was seen in men who were moderately thin (drawing 2) in childhood (P trend = 0.01). Using BMI <22.5 as a reference, we observed inverse associations between BMI 22.5 to <25 at age 20 and all prostate cancer subtypes (ORs in the range 0.72-0.82), and between mean adult BMI 25 to <27.5 and low-intermediate-risk disease (OR 0.75, 95 % CI 0.55-1.02). Moderate adult weight gain increased the risk of disease in men with low BMI at start and in short men.

CONCLUSIONS

Our comprehensive life-course approach revealed no convincing associations between anthropometric measures and prostate cancer risk. However, we found some leads that deserve further investigation, particularly for early-life body size. Our study highlights the importance of the time window of exposure in prostate cancer development.

Connective tissue growth factor regulates adipocyte differentiation of mesenchymal stromal cells and facilitates leukemia bone marrow engraftment

Mesenchymal stromal cells (MSCs) are a major component of the leukemia bone marrow (BM) microenvironment. Connective tissue growth factor (CTGF) is highly expressed in MSCs, but its role in the BM stroma is unknown. Therefore, we knocked down (KD) CTGF expression in human BM-derived MSCs by CTGF short hairpin RNA. CTGF KD MSCs exhibited fivefold lower proliferation compared with control MSCs and had markedly fewer S-phase cells. CTGF KD MSCs differentiated into adipocytes at a sixfold higher rate than controls in vitro and in vivo. To study the effect of CTGF on engraftment of leukemia cells into BM, an in vivo model of humanized extramedullary BM (EXM-BM) was developed in NOD/SCID/IL-2rg(null) mice. Transplanted Nalm-6 or Molm-13 human leukemia cells engrafted at a threefold higher rate in adipocyte-rich CTGF KD MSC-derived EXM-BM than in control EXM-BM. Leptin was found to be highly expressed in CTGF KD EXM-BM and in BM samples of patients with acute myeloid and acute lymphoblastic leukemia, whereas it was not expressed in normal controls. Given the established role of the leptin receptor in leukemia cells, the data suggest an important role of CTGF in MSC differentiation into adipocytes and of leptin in homing and progression of leukemia.

High incidence of prostate cancer metastasis in Afro-Brazilian men with low educational levels: a retrospective observational study

BACKGROUND

This study investigated factors related to ethnicity and educational level, their correlation with tumor stage at the time of diagnosis, and their influence on treatment outcomes in patients with prostate cancer.

METHODS

In this retrospective observational study, we analyzed the medical records of 1,349 male patients treated for prostatic adenocarcinoma. We collected information about sociodemographic variables, including educational level and self-reported skin color. We also classified the disease according whether it was to more likely to present with metastasis and measured the tumor response to treatment.

RESULTS

Less-educated (<8 years of education) individuals were 4.8 times more likely to develop metastasis than those with more education (>11 years of education; p < 0.001). Similarly, patients with a self-reported black skin color had a 300% increased risk of metastasis at diagnosis (p = 0.001). Distant metastasis was independently correlated with worse outcomes, such that individuals with distant metastasis were 10 times more likely to die than were those without distant metastasis.

CONCLUSIONS

Patients with self-reported black skin color and <8 years of education were more likely to display advanced disease at the time of diagnosis compared with their counterparts. Only the presence of metastasis was independently associated with mortality or progressive disease.

Diabetes mellitus and prostate cancer risk of different grade or stage: a systematic review and meta-analysis

AIM

Prior studies have reported that diabetes mellitus might reduce the overall prostate cancer risk. We examined this association by conducting a detailed meta-analysis of the studies published in peer-reviewed literature on the association between diabetes mellitus and prostate cancer risk of different stage or grade.

METHODS

A comprehensive search for articles of MEDLINE and EMBASE databases and bibliographies of retrieved articles published up to October 23, 2012 was performed. Methodological quality assessment of the trials was based on the Newcastle-Ottawa Scale. Meta-analysis was performed using STATA 12.0.

RESULTS

We included 9 studies in the meta-analysis (5 studies examining the relation of different stage only, 2 studies for grade only, and 2 studies for both grade and stage), and found an inverse association between diabetes mellitus and prostate cancer of different stage or grade. The relative risk (RRs) was moderately stronger for low grade (RR 0.74, 95% confidence interval (CI), 0.64-0.86) and localized disease (RR 0.72, 95% CI 0.67-0.76) compared with high grade (RR 0.78, 95% CI 0.67-0.90) and advanced disease (RR 0.85, 95% CI 0.75-0.97).

CONCLUSION

This study suggests an inverse relationship between diabetes mellitus and prostate cancer of different stage or grade. Possible biases underlying this association are discussed.

Lifestyle factors in cancer survivorship

Lifestyle factors have been linked to the risk of developing many common malignancies and, increasingly, to prognosis. Observational evidence has shown a relationship between so-called energy balance factors (ie, diet, physical activity, and body weight) and risk of cancer recurrence and mortality in cancers of the breast, prostate, colon and, perhaps, other cancers. Interventional work has shown that individuals who make favorable changes in these lifestyle factors after cancer diagnosis feel better, experience less fatigue, and may possibly even decrease risk of cancer recurrence. Other lifestyle behaviors, such as smoking and alcohol consumption, have also been linked to the development of common cancers and may have important health consequences for cancer survivors. This article reviews the evidence that links lifestyle factors to cancer outcomes, provides clinical recommendations for cancer survivors, and describes future directions for lifestyle research in cancer survivors.

The impact of cow's milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer

Prostate cancer (PCa) is dependent on androgen receptor signaling and aberrations of the PI3K-Akt-mTORC1 pathway mediating excessive and sustained growth signaling. The nutrient-sensitive kinase mTORC1 is upregulated in nearly 100% of advanced human PCas. Oncogenic mTORC1 signaling activates key subsets of mRNAs that cooperate in distinct steps of PCa initiation and progression. Epidemiological evidence points to increased dairy protein consumption as a major dietary risk factor for the development of PCa. mTORC1 is a master regulator of protein synthesis, lipid synthesis and autophagy pathways that couple nutrient sensing to cell growth and cancer. This review provides evidence that PCa initiation and progression are promoted by cow´s milk, but not human milk, stimulation of mTORC1 signaling. Mammalian milk is presented as an endocrine signaling system, which activates mTORC1, promotes cell growth and proliferation and suppresses autophagy. Naturally, milk-mediated mTORC1 signaling is restricted only to the postnatal growth phase of mammals. However, persistent consumption of cow´s milk proteins in humans provide highly insulinotropic branched-chain amino acids (BCAAs) provided by milk´s fast hydrolysable whey proteins, which elevate postprandial plasma insulin levels, and increase hepatic IGF-1 plasma concentrations by casein-derived amino acids. BCAAs, insulin and IGF-1 are pivotal activating signals of mTORC1. Increased cow´s milk protein-mediated mTORC1 signaling along with constant exposure to commercial cow´s milk estrogens derived from pregnant cows may explain the observed association between high dairy consumption and increased risk of PCa in Westernized societies. As well-balanced mTORC1-signaling plays an important role in appropriate prostate morphogenesis and differentiation, exaggerated mTORC1-signaling by high cow´s milk consumption predominantly during critical growth phases of prostate development and differentiation may exert long-term adverse effects on prostate health. Attenuation of mTORC1 signaling by contemporary Paleolithic diets and restriction of dairy protein intake, especially during mTORC1-dependent phases of prostate development and differentiation, may offer protection from the most common dairy-promoted cancer in men of Western societies.