Body mass index and weight change in men with prostate cancer: progression and mortality

New Horizons: Epidemiology of Obesity, Diabetes Mellitus, and Cancer Prognosis

The global prevalence of obesity and diabetes mellitus has increased in parallel with increasing cancer incidence, due to environmental and lifestyle factors and population aging. Metabolic diseases are associated with increased cancer risk, so a growing number of patients with cancer have coexistent obesity and/or diabetes mellitus. In this narrative review, we highlight recent evidence on the clinical impact of obesity and diabetes mellitus on the prognosis of prostate, breast, and colorectal cancer, and provide an overview of the underlying mechanisms. There is evidence that obesity is associated with increased risk of recurrence, and all-cause and cancer-specific mortality among adults with prostate, breast, and colorectal cancer. Diabetes mellitus is associated with increased all-cause and cancer-specific mortality for these 3 cancers, beyond any impact of obesity. Evidence also suggests increased risk of colorectal cancer recurrence in patients with diabetes mellitus. The underlying mechanisms are multifactorial and likely include hormonal imbalances and chronic inflammation that promote cancer cell growth. Obesity and diabetes mellitus are associated with increased risk of complications and side effects of cancer treatment. Associated comorbidities such as impaired kidney function, cardiovascular disease, and neuropathies may preclude the use of guideline cancer treatment and are competing causes of death. Cancer patients with metabolic diseases require a designated clinical program and a multidisciplinary approach involving oncologists, endocrinologists, surgeons, nutritionists, and physiotherapists, to ensure coordinated and optimized patient care.

Examining the role of social relationships on health and health behaviors in African American men with prostate cancer: a qualitative analysis

PURPOSE

Cancer survivor cohort studies document the positive impact of health behaviors on cancer survivorship by influencing quality of life, comorbidity burden, and cancer recurrence. Social networks can be instrumental in supporting health behavior changes. This study used qualitative interviews to explore how social networks may impact health and health behaviors of African American Prostate Cancer Survivors (AAPCS) enrolled in Men Moving Forward (MMF), a lifestyle intervention designed with and for AAPCS. Specifically, we sought to understand how different relationships within social networks influence health and health behaviors, and to identify potential mechanisms for this influence.

METHODS

Eighteen men who completed the MMF intervention participated in a semi-structured interview which explored social connections, health and health behaviors, stress, and the cancer experience. Interviews were recorded and transcribed, and thematic analysis was performed by two coders.

RESULTS

Participants described robust social networks of friends and family. Four distinct yet overlapping themes were identified that described how relationships influence health and health behaviors among AAPCS: (1) provision of knowledge, (2) health and behavior history, (3) encouragement and support, and (4) shared behavior.

CONCLUSIONS

These results provide initial insight into the types of relationships that influence health, and the intersecting and multifaceted mechanisms through which this influence occurs.

Association of Baseline Pre-Diagnosis and Post-Diagnosis Obesity and Weight Change with Cardiovascular Risk and Survival Among Nonmetastatic Prostate Cancer Survivors

INTRODUCTION

Obesity in prostate cancer survivors may increase mortality. Better characterization of this effect may allow better counseling on obesity as a targetable lifestyle factor to reduce mortality in prostate cancer survivors. The purpose of this study was to determine whether pre- and post-diagnostic obesity and weight change affect all-cause mortality, cardiovascular disease specific mortality, and prostate cancer specific mortality in patients with nonmetastatic prostate cancer.

PATIENTS AND METHODS

We performed a retrospective cohort analysis of 5,077 patients diagnosed with localized prostate cancer from 1997 to 2017 with median follow-up of 15.5 years. The Utah Population Database linked to the Utah Cancer Registry was used to identify patients at a variety of treatment centers.

RESULTS

Pre-diagnosis obesity was associated with a 62% increased risk of cardiovascular disease specific mortality and a 34% increased risk of all-cause mortality (HR 1.62, 95% CI 1.05-2.50; HR 1.34, 95% CI 1.07-1.67, respectively). Post-diagnosis obesity increased the risk of cardiovascular disease specific mortality (HR 1.83, 95% CI 1.31-2.56) and all-cause mortality (HR 1.37, 95% CI 1.16-1.64) relative to non-obese men. We found no association between pre-diagnostic obesity or post-diagnostic weight gain and prostate cancer specific mortality.

CONCLUSION

Our study strengthens the conclusion that pre-, post-diagnostic obesity and weight gain increase cardiovascular disease and all-cause mortality but not prostate cancer specific mortality compared to healthy weight men. An increased emphasis on weight management may improve mortality for prostate cancer survivors who are obese.

Efficacy of multidisciplinary interventions in preventing metabolic syndrome and improving body composition in prostate cancer patients treated with androgen deprivation therapy: A systematic review and meta-analysis

BACKGROUND

Exercise is known to reduce adverse side effects of androgen-deprivation therapy (ADT) on quality of life, bone health and fatigue for prostate cancer (PCa) patients. We conducted a systematic review with meta-analysis to evaluate the effect of multidisciplinary interventions on body composition and metabolic syndrome (MetS) in ADT-treated PCa patients.

METHODS

A systematic review and meta-analysis were conducted based on searches of EMBASE, MEDLINE, CENTRAL and Scopus databases from inception to March 2023. Participants included ADT-treated PCa patients who received multidisciplinary interventions including exercise, diet, nutrition, pharmacotherapy, bariatric surgery, or psychological/behavioural therapy. Primary outcomes were changes in body composition and MetS, with prostate-specific antigen (PSA) as a secondary outcome. After meta-analysis, results were reported in mean difference, 95% confidence interval and p-value, with forest plots. Additionally, we conducted subgroup analyses to compare the effect of different interventions.

RESULTS

Thirty-three articles met the eligibility criteria out of 1443 articles and 28 studies were included in meta-analysis. Of 33 studies, 17 included exercise-only interventions and 10 included exercise + diet/nutrition interventions, but no studies included diet/nutrition-only interventions. All studies employed multidisciplinary approaches in developing or delivering the interventions. Most studies (85%) had low-moderate risk of bias, thus providing good evidence to this review. Overall, interventions had a positive effect on body composition measures; lean mass (LM):0.82 kg (95% CI:0.47,1.17;p < 0.00001), body fat mass (BFM):-0.68 kg (95% CI:-1.12,-0.24;p = 0.002), fat-free mass:0.75 kg (95% CI:0.14,1.37;p = 0.02) and body fat percentage (BFP):-0.99% (95% CI:-1.29,-0.68;p < 0.00001), as well as on MetS; waist circumference:-1.95 cm (95% CI:-3.10,-0.79;p = 0.0009), systolic blood pressure:-3.43 mmHg (95% CI:-6.36,-0.50;p = 0.02) and diastolic blood pressure:-2.48 mmHg (95% CI:-4.19,-0.76;p = 0.005). Subgroup-analyses showed that a combined approach including exercise + diet/nutrition was most effective in improving BFP, WC, SBP and DBP whereas exercise was more effective in improving LM and BFM.

CONCLUSIONS

In ADT-treated PCa patients, multidisciplinary interventions, especially those combining exercise and diet/nutrition, can improve body composition and metabolic health.

Association between adiposity after diagnosis of prostate cancer and mortality: systematic review and meta-analysis

Objective

To explore the associations between adiposity indices, assessed at or after a diagnosis of prostate cancer, and mortality.

Design

Systematic review and meta-analysis.

Data sources

PubMed and Embase, from inception to 16 November 2022.

Eligibility criteria for selecting studies

Cohort studies or randomised controlled trials of men with a diagnosis of prostate cancer that investigated the associations between adiposity (body mass index, waist and hip circumference, waist-to-hip ratio, and subcutaneous and visceral adipose tissue) after diagnosis and mortality outcomes. A modified version of the risk of bias for nutrition observational studies tool was used to assess risk of bias.

Results

79 studies were identified that investigated adiposity indices after a diagnosis of prostate cancer in relation to mortality. No randomised controlled trials were found. A non-linear dose-response meta-analysis indicated a J shaped association between body mass index and all cause mortality (33 910 men, 11 095 deaths, 17 studies). The highest rate of all cause mortality was found at the lowest and upper range of the distribution: 11-23% higher rate for a body mass index of 17-21 and 4-43% higher rate for a body mass index of 30-40. The association between body mass index and mortality specific to prostate cancer was flat until body mass index reached 26-27, and then increased linearly by 8-66% for a body mass index of 30-40 (33 137 men, 2947 deaths, 13 studies), but the 95% confidence intervals were wide. These associations did not differ in most predefined subgroups by study design, number of deaths, anthropometric assessment, follow-up time, geographical location, prostate cancer risk group, and adjustment variables. No associations were found in meta-analyses between 10 cm increases in waist circumference and all cause mortality or mortality specific to prostate cancer, but only three studies were available. The few studies with data on change in weight, waist-to-hip ratio, and subcutaneous and visceral adipose tissue reported conflicting results.

Conclusions

This review suggests that patients with prostate cancer might benefit from maintaining a healthy weight and avoiding obesity. Future studies should investigate adiposity across different stages of cancer survivorship and use various parameters for distribution of adipose tissue.

Systematic review registration

Open Science Framework https://osf.io/qp3c4.

A Healthy Lifestyle in Men at Increased Genetic Risk for Prostate Cancer

BACKGROUND

Prostate cancer is the most heritable cancer. There is a need to identify possible modifiable factors for men at an increased risk of prostate cancer due to genetic factors.

OBJECTIVE

To examine whether men at an increased genetic risk of prostate cancer can offset their risk of disease or disease progression by adhering to a healthy lifestyle.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively followed 12 411 genotyped men in the Health Professionals Follow-up Study (1993-2019) and the Physicians' Health Study (1983-2010). Genetic risk of prostate cancer was quantified using a polygenic risk score (PRS). A healthy lifestyle was defined by healthy weight, vigorous physical activity, not smoking, and a healthy diet.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall and lethal prostate cancer events (metastatic disease/prostate cancer-specific death) were analyzed using time-to-event analyses estimating hazard ratios (HRs) and lifetime risks.

RESULTS AND LIMITATIONS

During 27 yr of follow-up, 3005 overall prostate cancer and 435 lethal prostate cancer events were observed. The PRS enabled risk stratification not only for overall prostate cancer, but also for lethal disease with a four-fold difference between men in the highest and lowest quartiles (HR, 4.32; 95% confidence interval [CI], 3.16-5.89). Among men in the highest PRS quartile, adhering to a healthy lifestyle was associated with a decreased rate of lethal prostate cancer (HR, 0.55; 95% CI, 0.36-0.86) compared with having an unhealthy lifestyle, translating to a lifetime risk of 1.6% (95% CI, 0.8-3.1%) among the healthy and 5.3% (95% CI, 3.6-7.8%) among the unhealthy. Adhering to a healthy lifestyle was not associated with a decreased risk of overall prostate cancer.

CONCLUSIONS

Our findings suggest that a genetic predisposition for prostate cancer is not deterministic for a poor cancer outcome. Maintaining a healthy lifestyle may provide a way to offset the genetic risk of lethal prostate cancer.

PATIENT SUMMARY

This study examined whether the genetic risk of prostate cancer can be attenuated by a healthy lifestyle including a healthy weight, regular exercise, not smoking, and a healthy diet. We observed that adherence to a healthy lifestyle reduced the risk of metastatic disease and prostate cancer death among men at the highest genetic risk. We conclude that men at a high genetic risk of prostate cancer may benefit from adhering to a healthy lifestyle.

Improving Whole Tomato Transformation for Prostate Health: Benign Prostate Hypertrophy as an Exploratory Model

It is well-established that the beneficial properties of single phytonutrients can be better attained when they are taken with the complex of the molecules present in their natural milieu. Tomato, the fruit providing the most comprehensive complex of prostate-health-preserving micronutrients, has been shown to be superior to its single-nutrient counterparts in decreasing the incidence of age-related prostate diseases. Herein, we describe a novel tomato food supplement enriched with olive polyphenols, containing cis-lycopene concentrations far exceeding those present in industry-produced tomato commodities. The supplement, endowed with antioxidant activity comparable to that of N-acetylcysteine, significantly reduced, in experimental animals, the blood levels of prostate-cancer-promoting cytokines. In prospective, randomized, double-blinded, placebo-controlled studies performed on patients affected by benign prostatic hyperplasia, its uptake significantly improved urinary symptoms and quality of life. Therefore, this supplement can complement and, in some cases, be an alternative to current benign prostatic hyperplasia management. Furthermore, the product suppressed carcinogenesis in the TRAMP mouse model of human prostate cancer and interfered with prostate cancer molecular signaling. Thus, it may offer a step forward in exploring the potential of tomato consumption to delay or prevent the onset of age-related prostate diseases in high-risk individuals.

The Role of Isoflavones in the Prevention of Breast Cancer and Prostate Cancer

This narrative review summarizes epidemiological studies on breast cancer and prostate cancer with an overview of their global incidence distribution to investigate the relationship between these diseases and diet. The biological properties, mechanisms of action, and available data supporting the potential role of isoflavones in the prevention of breast cancer and prostate cancer are discussed. Studies evaluating the effects of isoflavones in tissue cultures of normal and malignant breast and prostate cells, as well as the current body of research regarding the effects of isoflavones attained through multiple modifications of cellular molecular signaling pathways and control of oxidative stress, are summarized. Furthermore, this review compiles literature sources reporting on the following: (1) levels of estrogen in breast and prostate tissue; (2) levels of isoflavones in the normal and malignant tissue of these organs in European and Asian populations; (3) average concentrations of isoflavones in the secretion of these organs (milk and semen). Finally, particular emphasis is placed on studies investigating the effect of isoflavones on tissues via estrogen receptors (ER).

White adipose tissue-derived factors and prostate cancer progression: mechanisms and targets for interventions

Obesity represents an important risk factor for prostate cancer, driving more aggressive disease, chemoresistance, and increased mortality. White adipose tissue (WAT) overgrowth in obesity is central to the mechanisms that lead to these clinical observations. Adipose stromal cells (ASCs), the progenitors to mature adipocytes and other cell types in WAT, play a vital role in driving PCa aggressiveness. ASCs produce numerous factors, especially chemokines, including the chemokine CXCL12, which is involved in driving EMT and chemoresistance in PCa. A greater understanding of the impact of WAT in obesity-induced progression of PCa and the underlying mechanisms has begun to provide opportunities for developing interventional strategies for preventing or offsetting these critical events. These include weight loss regimens, therapeutic targeting of ASCs, use of calorie restriction mimetic compounds, and combinations of compounds as well as specific receptor targeting strategies.

Weight loss for overweight and obese patients with prostate cancer: a study protocol of a randomised trial comparing clinic-based versus Telehealth delivered EXercise and nutrition intervention (the TelEX trial)

INTRODUCTION

Obese men with prostate cancer have an increased risk of biochemical recurrence, metastatic disease and mortality. For those undergoing androgen deprivation therapy (ADT), substantial increases in fat mass are observed in the first year of treatment. Recently, we showed that a targeted supervised clinic-based exercise and nutrition intervention can result in a substantial reduction in fat mass with muscle mass preserved in ADT-treated patients. However, the intervention needs to be accessible to all patients and not just those who can access a supervised clinic-based programme. The purpose of this study was to evaluate the efficacy of telehealth delivered compared with supervised clinic-based delivered exercise and nutrition intervention in overweight/obese patients with prostate cancer.

METHODS AND ANALYSIS

A single-blinded, two-arm parallel group, non-inferiority randomised trial will be undertaken with 104 overweight/obese men with prostate cancer (body fat percentage ≥25%) randomly allocated in a ratio of 1:1 to a telehealth-delivered, virtually supervised exercise and nutrition programme or a clinic-based, face-to-face supervised exercise and nutrition programme. Exercise will consist of supervised resistance and aerobic exercise performed three times a week plus additional self-directed aerobic exercise performed 4 days/week for the first 6 months. Thereafter, for months 7-12, the programmes will be self-managed. The primary endpoint will be fat mass. Secondary endpoints include lean mass and abdominal aortic calcification, anthropometric measures and blood pressure assessment, objective measures of physical function and physical activity levels, patient-reported outcomes and blood markers. Measurements will be undertaken at baseline, 6 months (post intervention), and at 12 months of follow-up. Data will be analysed using intention-to-treat and per protocol approaches.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Edith Cowan University Human Research Ethics Committee (ID: 2021-02157-GALVAO). Outcomes from the study will be published in academic journals and presented in scientific and consumer meetings.

TRIAL REGISTRATION NUMBER

ACTRN12621001312831.

Interventions for Improving Body Composition in Men with Prostate Cancer: A Systematic Review and Network Meta-analysis

PURPOSE

To perform a systematic review and network meta-analysis to investigate the most effective intervention for improving body composition outcomes in prostate cancer patients during or after treatment.

METHODS

A systematic search was undertaken in multiple databases from inception to December 2020. Randomized clinical trials examining the effects of exercise/physical activity and/or nutrition interventions on body composition and body weight measures in prostate cancer patients were included. The primary endpoints were both whole-body and regional fat mass and lean mass measures, with body weight and BMI as secondary outcomes. A frequentist random-effects network meta-analysis was undertaken to examine the clustering effect of intervention modalities or control groups on the outcomes of interest. The study protocol is publicly available on PROSPERO (CRD42020202339).

RESULTS

Fifty articles describing 47 trials (n = 3207) were included. Resistance training and combined resistance and aerobic exercise were the most effective interventions to reduce body fat percentage (-0.9%; 95% confidence interval [CI], -1.4% to -0.3%) and fat mass (-0.5 kg; 95% CI, -0.9 to -0.1 kg), respectively. For whole-body and regional lean mass, combined resistance and aerobic exercise + healthy diet (0.6 kg; 95% CI, 0.1 to 1.0 kg) and resistance training alone (0.7 kg, 95% CI: 0.4 to 1.0 kg) were the best intervention, respectively. A low-fat diet was the most effective for reducing body weight immediately after or at follow-up, while no intervention promoted significant reductions in BMI.

CONCLUSIONS

These results indicate that a resistance-based exercise program alone or combined with a general healthy diet are the most effective interventions for improving overall body composition in men with prostate cancer.

Obesity as a Risk Factor for Prostate Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of 280,199 Patients

Simple Summary

Results from individual studies on the association between obesity and prostate cancer mortality remain inconclusive; additionally, several large cohort studies have recently been conducted. We aimed to systematically review all available evidence and synthetize it using meta-analytic techniques. The results of our study showed that obesity was associated with prostate cancer specific mortality and all-cause mortality. The temporal association was consistent with a dose-response relationship. Our results demonstrated that obesity, a potentially modifiable prognostic factor, was associated with higher prostate cancer mortality. This study improved the evidence regarding the potential impact of lifestyle on improving prostate cancer prognosis. Strategies aimed at maintaining normal, or reducing abnormal, body mass index in diagnosed prostate cancer patients might improve survival. These results should guide urologists, oncologists, patients, policy-makers and primary care providers with respect to evidence-based practice and counselling concerning lifestyle changes after prostate cancer diagnosis.

Abstract

The aim of this study was to systematically review all evidence evaluating obesity as a prognostic factor for PC mortality. Cohort and case-control studies reporting mortality among PC patients stratified by body mass index (BMI) were included. The risk of mortality among obese patients (BMI ≥ 30) was compared with the risk for normal weight (BMI < 25) patients, pooling individual hazard ratios (HR) in random-effects meta-analyses. Reasons for heterogeneity were assessed in subgroup analyses. Dose-response associations for BMI per 5 kg/m² change were assessed. Among 7278 citations, 59 studies (280,199 patients) met inclusion criteria. Obesity was associated with increased PC-specific mortality (HR: 1.19, 95% CI: 1.10–1.28, I²: 44.4%) and all-cause mortality (HR: 1.09, 95% CI: 1.00–1.18, I²: 43.9%). There was a 9% increase (95% CI: 5–12%, I²: 39.4%) in PC-specific mortality and 3% increase (95% CI: 1–5%, I²: 24.3%) in all-cause mortality per 5 kg/m² increase in BMI. In analyses restricted to the higher quality subgroup (NOS ≥ 8), obesity was associated with increased PC-specific mortality (HR: 1.24, 95% CI: 1.14–1.35, I²: 0.0%) and maintained the dose-response relationship (HR: 1.11 per 5 kg/m² increase in BMI, 95% CI: 1.07–1.15, I²: 26.6%). Obesity had a moderate, consistent, temporal, and dose-response association with PC mortality. Weight control programs may have a role in improving PC survival.

Obesity and low levels of physical activity impact on cardiopulmonary fitness in older men after treatment for prostate cancer

The purpose of this study was to compare fitness parameters and cardiovascular disease risk of older and younger men with prostate cancer (PCa) and explore how men's fitness scores compared to normative age values. 83 men were recruited post-treatment and undertook a cardiopulmonary exercise test (CPET), sit-to-stand, step-and-grip strength tests and provided blood samples for serum lipids and HbA1c. We calculated waist-to-hip ratio, cardiovascular risk (QRISK2), Charlson comorbidity index (CCI) and Godin leisure-time exercise questionnaire [GLTEQ]. Age-group comparisons were made using normative data. Men > 75 years, had lower cardiopulmonary fitness, as measured by VO₂ Peak (ml/kg/min) 15.8 + 3.8 p < 0.001, and lower grip strength(28.6+5.2 kg p < 0.001) than younger men. BMI ≥30kg/m² and higher blood pressure all contributed to a QRisk2 score indicative of 20% chance of cardiovascular risk within 10 years (mean: 36.9-6.1) p < 0.001. Age, BMI and perceived physical activity were significantly associated with lower cardiopulmonary fitness. Men with PCa > 75 years had more cardiovascular risk factors compared to normative standards for men of their age. Although ADT was more frequent in older men, this was not found to be associated with cardiopulmonary fitness, but obesity and low levels of physical activity were. Secondary prevention should be addressed in men with PCa to improve men's overall health.

Post-Diagnostic Dietary and Lifestyle Factors and Prostate Cancer Recurrence, Progression, and Mortality

PURPOSE OF REVIEW

This study aimed to summarize evidence published between 1999 and June 2020 examining diet and lifestyle after prostate cancer (PC) diagnosis in relation to risk of biochemical recurrence, PC progression, and PC-specific mortality.

RECENT FINDINGS

Secondary prevention is an important research area in cancer survivorship. A growing number of studies have reported associations between post-diagnostic modifiable behaviors and risk of PC outcomes. Evidence on modifiable lifestyle factors and PC remains limited. Where multiple studies exist, findings are often mixed. However, studies consistently suggest that smoking and consumption of whole milk/high-fat dairy are associated with higher risk of PC recurrence and mortality. In addition, physical activity and ½ to 1 glass of red wine/day have been associated with lower risk of recurrence and PC-specific mortality. Greater inclusion of racially/ethnically diverse groups in future research is necessary to understand these relationships in populations most impacted by adverse PC outcomes.

Association of Obesity With Survival Outcomes in Patients With Cancer: A Systematic Review and Meta-analysis

Importance

Obesity, defined as a body mass index (BMI) greater than 30, is associated with a significant increase in the risk of many cancers and in overall mortality. However, various studies have suggested that patients with cancer and no obesity (ie, BMI 20-25) have worse outcomes than patients with obesity.

Objective

To assess the association between obesity and outcomes after a diagnosis of cancer.

Data Sources

PubMed, the Cochrane Library, and EMBASE were searched from inception to January 2020.

Study Selection

Studies reporting prognosis of patients with obesity using standard BMI categories and cancer were included. Studies that used nonstandard BMI categories, that were limited to children, or that were limited to patients with hematological malignant neoplasms were excluded. Screening was performed independently by multiple reviewers. Among 1892 retrieved studies, 203 (17%) met inclusion criteria for initial evaluation.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were reporting guideline was followed. Data were extracted by multiple independent reviewers. Risk of death, cancer-specific mortality, and recurrence were pooled to provide an adjusted hazard ratio (HR) with a 95% CI . A random-effects model was used for the retrospective nature of studies.

Main Outcomes and Measures

The primary outcome of the study was overall survival (OS) in patients with cancer, with and without obesity. Secondary end points were cancer-specific survival (CSS) and progression-free survival (PFS) or disease-free survival (DFS). The risk of events was reported as HRs with 95% CIs, with an HR greater than 1 associated with a worse outcome among patients with obesity vs those without.

Results

A total of 203 studies with 6 320 365 participants evaluated the association of OS, CSS, and/or PFS or DFS with obesity in patients with cancer. Overall, obesity was associated with a reduced OS (HR, 1.14; 95% CI, 1.09-1.19; P < .001) and CSS (HR, 1.17; 95% CI, 1.12-1.23; P < .001). Patients were also at increased risk of recurrence (HR, 1.13; 95% CI, 1.07-1.19; P < .001). Conversely, patients with obesity and lung cancer, renal cell carcinoma, or melanoma had better survival outcomes compared with patients without obesity and the same cancer (lung: HR, 0.86; 95% CI, 0.76-0.98; P = .02; renal cell: HR, 0.74; 95% CI, 0.53-0.89; P = .02; melanoma: HR, 0.74; 95% CI, 0.57-0.96; P < .001).

Conclusions and Relevance

In this study, obesity was associated with greater mortality overall in patients with cancer. However, patients with obesity and lung cancer, renal cell carcinoma, and melanoma had a lower risk of death than patients with the same cancers without obesity. Weight-reducing strategies may represent effective measures for reducing mortality in these patients.

Nutrition Education Seminars for Prostate Cancer-Diet and Prostate Program: Evaluation and Recommendations (DAPPER Study)

Nutrition is important for prostate cancer (PCa) care as it may influence PCa progression and risk of comorbid diseases. The aim of this pilot study was to assess changes in knowledge and satisfaction in men with PCa following attendance at a nutrition education seminar. Fifty-two men with PCa attended nutrition education seminars instructed by a Registered Dietitian. Participants completed the Revised General Nutrition Knowledge Questionnaire (GNKQ-R) preseminar and 2 weeks postseminar, along with a satisfaction survey. Increased nutrition knowledge was observed through a significant (P = 0.023) improvement in mean scores of 71.6% (P < 0.005) preseminar compared with 79.3% (P < 0.005) postseminar on the GNKQ-R. Participants reported the seminar as a satisfactory method for meeting their diet information needs. Using thematic analysis 3 themes emerged: importance of diet information, desire for an integrative approach, and the value of group learning. This pilot study found that a group nutrition education seminar may be an effective and satisfactory approach to fulfilling the dietary information needs of this population. Group education may be an economically sustainable approach with potential application in other tumour sites or health conditions.

Postdiagnosis Body Mass Index, Weight Change, and Mortality From Prostate Cancer, Cardiovascular Disease, and All Causes Among Survivors of Nonmetastatic Prostate Cancer

PURPOSE

To investigate the association of postdiagnosis body mass index (BMI) and weight change with prostate cancer-specific mortality (PCSM), cardiovascular disease-related mortality (CVDM), and all-cause mortality among survivors of nonmetastatic prostate cancer.

METHODS

Men in the Cancer Prevention Study II Nutrition Cohort diagnosed with nonmetastatic prostate cancer between 1992 and 2013 were followed for mortality through December 2016. Current weight was self-reported on follow-up questionnaires approximately every 2 years. Postdiagnosis BMI was obtained from the first survey completed 1 to < 6 years after diagnosis. Weight change was the difference in weight between the first and second postdiagnosis surveys. Deaths occurring within 4 years of the follow-up were excluded to reduce bias from reverse causation. Analyses of BMI and weight change included 8,330 and 6,942 participants, respectively.

RESULTS

Postdiagnosis BMI analyses included 3,855 deaths from all causes (PCSM, n = 500; CVDM, n = 1,155). Using Cox proportional hazards models, hazard ratios (HRs) associated with postdiagnosis obesity (BMI ≥ 30 kg/m2) compared with healthy weight (BMI 18.5 to < 25.0 kg/m2) were 1.28 for PCSM (95% CI, 0.96 to 1.67), 1.24 for CVDM (95% CI, 1.03 to 1.49), and 1.23 for all-cause mortality (95% CI, 1.11 to 1.35). Weight gain analyses included 2,973 deaths (PCSM, n = 375; CVDM, n = 881). Postdiagnosis weight gain (> 5% of body weight), compared with stable weight (± < 3%), was associated with a higher risk of PCSM (HR, 1.65; 95% CI, 1.21 to 2.25) and all-cause mortality (HR, 1.27; 95% CI, 1.12 to 1.45) but not CVDM.

CONCLUSION

Results suggest that among survivors of nonmetastatic prostate cancer with largely localized disease, postdiagnosis obesity is associated with higher CVDM and all-cause mortality, and possibly higher PCSM, and that postdiagnosis weight gain may be associated with a higher mortality as a result of all causes and prostate cancer.

Decreased biochemical progression in patients with castration-resistant prostate cancer using a novel mefenamic acid anti-inflammatory therapy: A randomized controlled trial

Prostate cancer (PCa) is the second most common non-dermatological cancer in men and is a growing public health problem. Castration-resistant disease (CRD) is the most advanced stage of the disease and is difficult to control. Patients with CRD may no longer accept conventional therapies as they are not in appropriate clinical conditions or they refuse to receive it. Given that inflammation is an essential component of CRD origin and progression, anti-inflammatory agents could be a therapeutic option with fenamates as one of the proposed choices. A prospective, randomized, double-blinded, 2-arm, parallel group, phase II-III clinical trial was performed involving 20 patients with CRD-PCa (with a prostate specific antigen level <100 ng/ml) that were undergoing androgen deprivation therapy (ADT) and did not accept any established treatment for that disease stage. In addition to ADT, 10 patients received placebo and 10 received mefenamic acid (500 mg orally every 12 h) for 6 months. The primary endpoint was the change in serum prostate-specific antigen (PSA) at 6 months. The PSA levels decreased significantly with mefenamic acid (an average 42% decrease), whereas there was an average 55% increase in the placebo group (P=0.024). In the patients treated with the placebo, 70% had biochemical disease progression (an increase of ≥25% in PSA levels), which did not occur in any of the patients treated with mefenamic acid (relative risk=0.12; 95% confidence interval, 0.01-0.85; P=0.033). There was a significant increase in quality of life (EQ-5D-5L score) and body mass index (BMI) with the experimental treatment. In conclusion, mefenamic acid administration decreased biochemical progression in patients with castration resistant PCa, improved their quality of life and increased their BMI. Future studies are required in order to strengthen the findings of the present clinical trial. Trial registration, Cuban Public Registry of Clinical Trials Database RPCEC00000248, August 2017.

Diet and Lifestyle in Prostate Cancer

A variety of diet and lifestyle factors have been studied with respect to prostate cancer risk in large, prospective cohort studies. In spite of this work, and in contrast to other common cancers, few modifiable risk factors have been firmly established as playing a role in prostate cancer. There are several possible explanations for the lack of well-established risk factors. First, prostate cancer has among the highest heritability of all common cancers; second, early life exposures may play an important role in risk, rather than mid- and later-life exposures assessed in most epidemiological studies. Finally, prostate-specific antigen (PSA) screening plays a critical role in prostate cancer detection and incidence rates, which has important implications for epidemiological studies.Among modifiable risk factors, smoking and obesity are consistently associated with higher risk specifically of advanced prostate cancer. There is also considerable evidence for a positive association between dairy intake and overall prostate cancer risk, and an inverse association between cooked tomato/lycopene intake and risk of advanced disease. Several other dietary factors consistently associated with risk in observational studies, including selenium and vitamin E, have been cast into doubt by results from clinical trials. Results for other well-studied dietary factors, including fat intake, red meat, fish, vitamin D, soy and phytoestrogens are mixed.In practical terms, men concerned with prostate cancer risk should be encouraged to stop smoking, be as physically active as possible, and achieve or maintain a healthy weight. These recommendations also have the advantage of having a positive impact on risk of type 2 diabetes, cardiovascular disease, and other chronic diseases. Reducing dairy intake while increasing consumption of fish and tomato products is also reasonable advice.

Whole Exome Sequencing Identifies Putative Predictors of Recurrent Prostate Cancer with High Accuracy

Prostate cancer (PCa) is a highly common cancer among men but lacks robust diagnostics that can predict disease recurrence after initial treatment, for example, with radical prostatectomy. Recent advances in genomics and next-generation sequencing heralded the discovery of biomarkers such as the androgen receptor gene (AR) splice events, the TMPRSS2:EGR gene fusion, long noncoding RNA MALAT-1 and SCHLAP1 for PCa prognosis. Still, the question of why some patients experience recurrence, whereas others do not introduce marked uncertainty for both patients and physicians. We report here the whole exome sequencing of 30 recurrent and 44 nonrecurrent PCa patients. We identified 72 and 34 specific somatic single nucleotide variations in the recurrent and the nonrecurrent group, respectively, and developed a classification model to forecast PCa recurrence using a random forest model. The model displayed a sensitivity and specificity of 87.8% and 94.4%, respectively, for identifying the patients with recurrent PCa. These observations warrant further research in independent and larger clinical samples so as to inform future diagnostics innovation for PCa prognosis and recurrence.

Poor Adherence to International Cancer Prevention Recommendations Among Patients With Prostate Cancer: First Results From the MARTINI-Lifestyle Cohort

BACKGROUND

Promotion of a healthy lifestyle in patients with prostate cancer (PCa) has gained traction to increase patient investment in his/her health care practices, improve patient quality of life, and improve survival outcomes.

OBJECTIVE

To investigate adherence of patients with PCa to healthy lifestyle recommendations from the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR).

DESIGN, SETTING, AND PARTICIPANTS

A total of 2227 men with PCa scheduled for radical prostatectomy in the Martini-Klinik at the University Hospital Hamburg-Eppendorf, Hamburg, Germany between January 2016 and December 2017.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Age and clinical characteristics were collected at the time of the diagnosis. Assessment of diet and physical activity data were obtained via e-mail surveys using validated questionnaires developed for the European Prospective Investigation into Cancer and Nutrition (EPIC) study [food frequency questionnaire, version 2 (FFQ2), EPIC-Physical Activity Questionnaire (EPIC-PAQ)]. Baseline characteristics were calculated as means and standard deviations for continuous data or counts and percentages for categorical data.

RESULTS AND LIMITATIONS

Patients followed 3.3 (±1.5) of the 10 WCRF/AICR recommendations. None of the participants reached all goals; 67.3% of the patients did not fulfill the criteria of a healthy normal weight, 33.5% reported no exercise at all, and 49.6% were characterized as current or ex-smokers. As to nutritional goals, 75.4% did not meet the recommended intake of meat, 88.8% reported a low consumption of fruit and vegetables, and 86% did not achieve the recommended fiber intake. Because these analyses are based on self-reported data of diet and lifestyle, a bias toward underreporting cannot be excluded.

CONCLUSIONS

First results of the MARTINI-Lifestyle cohort show that adherence to the AICR/WCRF recommendations for cancer prevention is poor.

PATIENT SUMMARY

Patients with prostate cancer scheduled for surgery do not adhere to cancer prevention guidelines. Thus, improving lifestyle habits may provide significant impact on patient health and quality of life.

Prevalence of Obesity and Incidence of Obesity-Related Comorbidities in Koreans Based on National Health Insurance Service Health Checkup Data 2006-2015

Background

The prevalence of obesity and related comorbidities is increasing worldwide, including in Korea. The Korean Society for the Study of Obesity released the Obesity Fact Sheet 2017 to address this problem in the Korean population.

Methods

Data from the National Health Insurance Service Health Checkup database from 2006 to 2015 were standardized by age and sex using the 2010 Census. The definition of obesity was a body mass index (BMI) ≥25 kg/m², and that of abdominal obesity was a waist circumference ≥90 cm in men and ≥85 cm in women. Multivariate adjusted Cox regression analysis was conducted, and hazard ratios (HRs) with 95% confidence intervals were calculated for comorbidities.

Results

From 2009 to 2015, the prevalence of obesity increased from 29.7% to 32.4%, and that of abdominal obesity increased from 18.4% to 20.8%. Obesity with abdominal obesity also increased from 15.1% to 17.7%. Between 2014 and 2015, the prevalence of obesity increased until 30-40 years of age, but decreased from 40-50 years of age in men. In women, it increased until the mid-70s, and decreased thereafter. Abdominal obesity increased from 20-30 years of age to 70-80 years of age, but decreased thereafter. The HRs for type 2 diabetes mellitus, hypertension, dyslipidemia, myocardial infarction, and ischemic stroke were elevated in subjects with abdominal obesity, and their incidence increased as the BMI increased, but slowed down at BMI ≥35 kg/m².

Conclusion

Based on the Obesity Fact Sheet 2017, strategies for reducing the prevalence of obesity and abdominal obesity are essential.

Lifestyle and Dietary Factors and Prostate Cancer Risk: A Multicentre Case-Control Study

This study aims to explore the association between fruit and vegetable intake, high fat, body mass index (BMI) score, physical activity, and the occurrence of prostate cancer among Jordanian men. A case-control study was conducted in three large referral hospitals. The sample included 165 prostate cancer patients in the case group and 177 healthy participants in the control group. The results showed that smoking (odds ratio [OR] = 0.32; 95% confidence interval [CI] = [0.18, 0.57]), a history of prostate infection (OR = 0.21; 95% CI = [0.11, 0.38]), high-fat intake (OR = 0.44; 95% CI = [0.23, 0.85]), and increased mean of BMI (OR = 1.08; 95% CI = [1.02, 1.13]) increased the likelihood of developing prostate cancer. Healthy diet and giving up smoking are recommended, as they may contribute to a reduction in the incidence of prostate cancer. More randomized clinical trials in this area are needed to strengthen the available evidence and reduce the effects of confounding variables.

Phase II prospective randomized trial of weight loss prior to radical prostatectomy

BACKGROUND

Obesity is associated with poorly differentiated and advanced prostate cancer and increased mortality. In preclinical models, caloric restriction delays prostate cancer progression and prolongs survival. We sought to determine if weight loss (WL) in men with prostate cancer prior to radical prostatectomy affects tumor apoptosis and proliferation, and if WL effects other metabolic biomarkers.

METHODS

In this Phase II prospective trial, overweight and obese men scheduled for radical prostatectomy were randomized to a 5–8 week WL program consisting of standard structured energy-restricted meal plans (1200–1500 Kcal/day) and physical activity or to a control group. The primary endpoint was apoptotic index in the radical prostatectomy malignant epithelium. Secondary endpoints were proliferation (Ki67) in the radical prostatectomy tissue, body weight, body mass index (BMI), waist to hip ratio, body composition, and serum PSA, insulin, triglyceride, cholesterol, testosterone, estradiol, leptin, adiponectin, interleukin 6, interleukin 8, insulin-like growth factor 1, and IGF binding protein 1.

RESULTS

Twenty-three patients were randomized to the WL intervention and twenty-one patients to the control group. Subjects in the intervention group had significantly more weight loss (WL:−3.7 ± 0.5 kg; Control:−1.6 ± 0.5 kg; p=0.007) than the control group and total fat mass was significantly reduced (WL:−2.1 ± 0.4; Control: 0.1 ± 0.3; p=0.015). There was no significant difference in apoptotic or proliferation index between the groups. Among the other biomarkers, triglyceride and insulin levels were significantly decreased in the WL compared to the control group.

CONCLUSIONS

In summary, this short-term WL program prior to radical prostatectomy resulted in significantly more WL in the intervention vs. the control group and was accompanied by significant reductions in body fat mass, circulating triglycerides, and insulin. However, no significant changes were observed in malignant epithelium apoptosis or proliferation. Future studies should consider a longer term or more intensive weight loss intervention.

Long-term weight loss after colorectal cancer diagnosis is associated with lower survival: The Colon Cancer Family Registry

BACKGROUND

Body weight is associated with colorectal cancer (CRC) risk and survival, but to the authors' knowledge, the impact of long-term postdiagnostic weight change is unclear. Herein, the authors investigated whether weight change over the 5 years after a diagnosis of CRC is associated with survival.

METHODS

CRC cases diagnosed from 1997 to 2008 were identified through 4 population-based cancer registry sites. Participants enrolled within 2 years of diagnosis and reported their height and weight 2 years prior. Follow-up questionnaires were administered approximately 5 years after diagnosis. Associations between change in weight (in kg) or body mass index (BMI) with overall and CRC-specific survival were estimated using Cox regression analysis adjusted for age, sex, American Joint Committee on Cancer stage of disease, baseline BMI, nonsteroidal anti-inflammatory drug use, smoking, time between diagnosis and enrollment, and study site.

RESULTS

At the 5-year postdiagnostic survey, 2049 participants reported higher (53%; median plus 5 kg), unchanged (12%), or lower (35%; median -4 kg) weight. Over a median of 5.1 years of subsequent follow-up (range, 0.3-9.9 years), 344 participants died (91 of CRC). Long-term weight loss (per 5 kg) was found to be associated with poorer overall survival (hazard ratio, 1.13; 95% confidence interval, 1.07-1.21) and CRC-specific survival (hazard ratio, 1.25; 95% confidence interval, 1.13-1.39). Significantly lower survival was similarly observed for relative weight loss (>5% vs ≤5% change), BMI reduction (per 1 unit), or BMI category change (overweight to normal vs remaining overweight).

CONCLUSIONS

Weight loss 5 years after a diagnosis of CRC was found to be significantly associated with decreased long-term survival, suggesting the importance of avoiding weight loss in survivors of CRC. Future research should attempt to further evaluate this association, accounting for whether this weight change was intentional or represents a marker of declining health. Cancer 2017;123:4701-4708. © 2017 American Cancer Society.

Change in Weight and Body Mass Index Associated With All-Cause Mortality in Korea: A Nationwide Longitudinal Study

CONTEXT

Many studies have reported conflicting evidence on the association between weight change and mortality.

OBJECTIVE

We investigated the association between weight change and subsequent all-cause mortality, using a large-scale, population-based cohort from the National Health Insurance System health checkup data between 2005 and 2015.

METHODS

A total of 11,524,763 subjects older than age 20 years were included. Weight was measured every 2 years and weight change over 4 years was divided into eight categories, from weight loss ≥15% to weight gain ≥20%, for every 5% of weight change. The hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality were analyzed using multivariable Cox proportional hazard models compared with the stable weight group (weight change <5%) after adjusting for age, sex, smoking, drinking, exercise, diabetes mellitus, hypertension, dyslipidemia, cancer, and income.

RESULTS

Weight loss was associated with increased mortality rates compared with weight gain; the group with weight loss ≥15% had the highest HR for all-cause mortality (HR, 2.598; 95% CI, 2.537 to 2.659). The HR for all-cause mortality in the ≥20% weight gain group was 1.784 (95% CI, 1.695 to 1.877). Across all body mass index (BMI) categories, weight loss ≥15% was associated with increased mortality rates and the highest mortality rates were found in the BMI ≥30 kg/m2 group (HR, 3.469; 95% CI, 2.236 to 5.381).

CONCLUSIONS

Weight change over 4 years showed a reverse J-shaped all-cause mortality curve, independent of BMI status. Weight loss was associated with a greater risk of mortality than was weight gain.

Weight change, obesity and risk of prostate cancer progression among men with clinically localized prostate cancer

Obesity is associated with an increased risk of fatal prostate cancer. We aimed to elucidate the importance and relevant timing of obesity and weight change for prostate cancer progression. We identified 5,158 men diagnosed with localized prostate cancer (clinical stage T1/T2) from 1986 to 2012 in the Health Professionals Follow-up Study. Men were followed for biochemical recurrence and lethal prostate cancer (development of distant metastasis or prostate cancer-specific mortality) until 2012. Cox regression estimated hazard ratios (HRs) for body mass index (BMI) at age 21, BMI at diagnosis, "long-term" weight change from age 21 to diagnosis and "short-term" weight change over spans of 4 and 8 years preceding diagnosis. Because weight, weight change and mortality are strongly associated with smoking, we repeated analyses among never smokers only (N = 2,559). Among all patients, neither weight change nor BMI (at age 21 or at diagnosis) was associated with lethal prostate cancer. Among never smokers, long-term weight gain was associated with an increased risk of lethal disease (HR for gaining >30 pounds vs. stable weight [±10 pounds] 1.59, 95% CI, 1.01-2.50, p-trend = 0.06). Associations between weight change, BMI and lethal prostate cancer were stronger for men with BMI ≥ 25 at age 21 compared to those with BMI < 25. Weight change and obesity were not associated with an increased risk of biochemical recurrence. Our findings among never smoker men diagnosed with localized prostate cancer suggest a positive association between long-term weight gain and risk of lethal prostate cancer. Metabolic changes associated with weight gain may promote prostate cancer progression.

Sociodemographic and economic factors are associated with weight gain between before and after cancer diagnosis: results from the prospective population-based NutriNet-Santé cohort

Purpose

While many cancer patients are affected by weight loss, others tend to gain weight, which may impact prognosis and risk of recurrence and of second cancer. The aim of this prospective study was to investigate weight variation between before and after cancer diagnosis and socio-demographic, economic, lifestyle and clinical factors associated with moderate-to-severe weight gain.

Methods

1051 incident cases of first primary cancer were diagnosed in the NutriNet-Santé cohort between 2009 and 2015. Weight was prospectively collected every 6 months since subjects’ inclusion (i.e. an average of 2y before diagnosis). Mean weights before and after cancer diagnosis were compared with paired Student's t-test. Factors associated with moderate-to-severe weight gain (≥5% of initial weight) were investigated by age and sex-adjusted logistic regression.

Results

Weight loss was observed in men (-3.54±4.39kg in those who lost weight, p=0.0002) and in colorectal cancer patients (-3.94±4.40kg, p=0.001). Weight gain was observed in breast and skin cancers (2.83±3.21kg, p=0.04, and 2.96±2.75kg, p=0.04 respectively). Women (OR=1.75[1.06-2.87],p=0.03), younger patients (2.44[1.51-3.70],p<0.0001), those with lower income (OR=1.30[1.01-1.72],p-trend=0.007), lower education (OR=1.32[1.03-2.70],p-trend=0.03), excess weight before diagnosis (OR=1.64[1.12-2.42],p=0.01), lower physical activity (OR=1.28[1.01-1.64],p=0.04) and those who stopped smoking (OR=4.31[1.99-9.35],p=0.005]) were more likely to gain weight. In breast cancer patients, induced menopause was associated with weight gain (OR=4.12[1.76-9.67]), but no association was detected for tumor characteristics or treatments.

Conclusion

This large prospective cohort provided original results on weight variation between before and after cancer diagnosis, highlighting different weight trajectories. Socio-demographic and economic factors appeared to influence the risk of weight gain, illustrating social inequalities in health.

Prostate cancer progression and mortality: a review of diet and lifestyle factors

PURPOSE

To review and summarize evidence on the role of diet and lifestyle factors and prostate cancer progression, with a specific focus on habits after diagnosis and the risk of subsequent disease recurrence, progression, or death.

METHODS

Given the well-documented heterogeneity of prostate cancer and the long survivorship of the majority of diagnoses, our goal was to summarize and describe modifiable risk factors for clinically relevant prostate cancer. We focused where possible on epidemiologic studies of post-diagnostic habits and prostate cancer progression, defined as recurrence (e.g., PSA risk, secondary treatment), metastasis, or death. Where data were limited, we also describe evidence on risk factors and indicators of prostate cancer aggressiveness at diagnosis.

RESULTS

A variety of dietary and lifestyle factors appear to affect prostate cancer progression. Several generally widely recommended lifestyle factors such as not smoking, maintaining a healthy body weight, and regular vigorous physical exercise also appear to affect prostate cancer progression. Several dietary factors, such as tomato sauce/lycopene, cruciferous vegetables, healthy sources of vegetable fats, and coffee, may also have a role in reducing risk of prostate cancer progression.

CONCLUSION

Diet and lifestyle factors, in particular exercise and smoking cessation, may reduce the risk of prostate cancer progression and death. These promising findings warrant further investigation, as their overall impact might be large.

Body mass index and mortality in prostate cancer patients: a dose-response meta-analysis

BACKGROUND

Previous studies concerning the association between body mass index (BMI) and mortality in prostate cancer yielded mixed results. We investigated the association by performing a meta-analysis of all available studies.

METHODS

Relevant studies were identified by searching PubMed and EMBASE to August 2015. We calculated the summary hazard ratio (HR) and 95% confidence interval (CI) using random-effects models. We estimated combined HRs associated with defined increments of BMI, using random-effects meta-analysis and dose-response meta-regression models.

RESULTS

Thirty-seven cohort studies and one case-control study involving 27 38 000 patients of prostate cancer were selected for meta-analysis. The summary results indicated higher prediagnosis BMI but not postdiagnosis BMI was associated with increased risk of death from prostate cancer. An increment of every 5 kg/m(2) in prediagnosis BMI was associated with a 15% higher prostate cancer-specific mortality (HR=1.15, 95% CI: 1.07-1.23, P<0.01). Prediagnosis or postdiagnosis BMI showed no effect on all-cause mortality in prostate cancer patients.

CONCLUSIONS

In conclusion, higher prediagnosis BMI is associated with a higher risk of death from prostate cancer. Considering the significant heterogeneity among included studies, these findings require confirmation in future studies.

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.

Obesity and cancer: mechanistic insights from transdisciplinary studies

Obesity is associated with a range of health outcomes that are of clinical and public health significance, including cancer. Herein, we summarize epidemiologic and preclinical evidence for an association between obesity and increased risk of breast and prostate cancer incidence and mortality. Moreover, we describe data from observational studies of weight change in humans and from calorie-restriction studies in mouse models that support a potential role for weight loss in counteracting tumor-promoting properties of obesity in breast and prostate cancers. Given that weight loss is challenging to achieve and maintain, we also consider evidence linking treatments for obesity-associated co-morbidities, including metformin, statins and non-steroidal anti-inflammatory drugs, with reduced breast and prostate cancer incidence and mortality. Finally, we highlight several challenges that should be considered when conducting epidemiologic and preclinical research in the area of obesity and cancer, including the measurement of obesity in population-based studies, the timing of obesity and weight change in relation to tumor latency and cancer diagnosis, and the heterogeneous nature of obesity and its associated co-morbidities. Given that obesity is a complex trait, comprised of behavioral, epidemiologic and molecular/metabolic factors, we argue that a transdisciplinary approach is the key to understanding the mechanisms linking obesity and cancer. As such, this review highlights the critical need to integrate evidence from both epidemiologic and preclinical studies to gain insight into both biologic and non-biologic mechanisms contributing to the obesity-cancer link.

Lifestyle and dietary factors in relation to prostate cancer risk

The aim of the present study was to determine the association between the socio-demographic, lifestyle factors, and dietary habits with the risk of prostate cancer (PC) in a case-control study of Spanish men. None of the socio-demographic, lifestyle or dietetic variables was found predictors of PC risk. Body mass index was associated with an increased risk for aggressive PC and fruit consumption with lower Gleason scores, thus less aggressive cancers. Nonetheless, after applying Bonferroni correction, these variables were not still associated with PC aggressiveness. More adequately, powered epidemiological studies that measure the effect of lifestyle and dietary intake in PC risk and aggressiveness are warranted to further elucidate the role of these modifiable factors on PC etiology.

Body mass index and mortality in men with prostate cancer

BACKGROUND

Body Mass index (BMI) has been shown to affect risk and mortality of several cancers. Prostate cancer and obesity are major public health concerns for middle-aged and older men. Previous studies of pre-diagnostic BMI have found an increased risk of prostate cancer mortality in obese patients.

OBJECTIVE

To study the associations between BMI at time of prostate cancer diagnosis and prostate cancer specific and overall mortality.

METHODS

BMI was analyzed both as a continuous variable and categorized into four groups based on the observed distribution in the cohort (BMI < 22.5, 22.5 < 25, 25 < 27.5 and ≥27.5 kg/m2). The association between BMI and mortality was assessed using stratified Cox proportional hazards models and by fitting regression splines for dose response analysis in 3,161 men diagnosed with prostate cancer. After 11 years of follow up via linkage to the population-based cause of death registry, we identified 1,161 (37%) deaths off which 690 (59%) were due to prostate cancer.

RESULTS

High BMI (BMI ≥ 27.5 kg/m2) was associated with a statistically significant increased risk of prostate cancer specific mortality (HR:1.44, 95% CI: 1.09-1.90) and overall mortality (HR:1.33, 95% CI: 1.09-1.63) compared to the reference group (BMI 22.5 < 25 kg/m2). Additionally, men with a low BMI (<22.5 kg/m2 ), had a statistically significant increased risk of prostate cancer specific mortality (HR:1.33, 95% CI: 1.02-1.74) and overall mortality (HR:1.36, 95% CI: 1.11-1.67) compared to the reference. However, this effect disappeared when men who died within the first two years of follow-up were excluded from the analyses while the increased risk of prostate cancer specific mortality and overall mortality remained statistically significant for men with a BMI ≥ 27.5 kg/m2 (HR:1.44, 95% CI: 1.09-1.90 and HR: 1.33, 95% CI: 1.09-1.63, respectively).

CONCLUSION

This study showed that a high BMI at time of prostate cancer diagnosis was associated with increased overall mortality.

Beyond meatless, the health effects of vegan diets: findings from the Adventist cohorts

Vegetarians, those who avoid meat, and vegans, additionally avoiding dairy and eggs, represent 5% and 2%, respectively, of the US population. The aim of this review is to assess the effects of vegetarian diets, particularly strict vegetarian diets (i.e., vegans) on health and disease outcomes. We summarized available evidence from three prospective cohorts of Adventists in North America: Adventist Mortality Study, Adventist Health Study, and Adventist Health Study-2. Non-vegetarian diets were compared to vegetarian dietary patterns (i.e., vegan and lacto-ovo-vegetarian) on selected health outcomes. Vegetarian diets confer protection against cardiovascular diseases, cardiometabolic risk factors, some cancers and total mortality. Compared to lacto-ovo-vegetarian diets, vegan diets seem to offer additional protection for obesity, hypertension, type-2 diabetes, and cardiovascular mortality. Males experience greater health benefits than females. Limited prospective data is available on vegetarian diets and body weight change. Large randomized intervention trials on the effects of vegetarian diet patterns on neurological and cognitive functions, obesity, diabetes, and other cardiovascular outcomes are warranted to make meaningful recommendations.