Systematic review of prostate cancer’s association with body size in childhood and young adulthood

General and abdominal obesity trajectories across adulthood, and risk of prostate cancer: results from the PROtEuS study, Montreal, Canada

PURPOSE

Greater body fatness is a probable cause of advanced prostate cancer (PCa). Body fat distribution and timing of exposure may be relevant. We investigated associations between body size trajectories and PCa incidence in a population-based case-control study in Montreal, Canada.

METHODS

Cases (n = 1,931), aged ≤ 75 years, were diagnosed with PCa in 2005-2009; 1,994 controls were selected from the electoral list. Interviews were conducted to assess body mass index (BMI) and Stunkard's silhouette at ages 20, 40, 50, 60 years, and before interview. Current waist and hip circumferences were measured, and a predictive model estimated waist circumference in the past. BMI and waist circumference trajectories were determined to identify subgroups. Logistic regression estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between anthropometric indicators and PCa.

RESULTS

Subjects with a current BMI ≥ 30 kg/m² had a lower risk of overall PCa (OR 0.71, 95% CI 0.59-0.85). Associations with adult BMI followed similar trends for less and more aggressive tumors, with stronger inverse relationships in early adulthood. Contrastingly, current waist circumference ≥ 102 cm was associated with elevated risk of high-grade PCa (OR 1.33, 95% CI 1.03-1.71). Men with increasing BMI or waist circumference adult trajectories had a lower risk of PCa, especially low-grade, than those in the normal-stable range. This was especially evident among men in the obese-increase group for BMI and waist circumference.

CONCLUSION

Abdominal obesity increased the risk of aggressive PCa. The inverse relationship between body size trajectories and PCa may reflect PSA hemodilution, lower detection, and/or a true etiological effect.

Associating the risk of three urinary cancers with obesity and overweight: an overview with evidence mapping of systematic reviews

BACKGROUND

The relationship between cancer with overweight and obesity has been extensively reported. However, the association between urinary cancers with these risk factors remains unclear, with existing reports showing conflicting findings. The current review, therefore, sought to clarify the latter association by assessing the methodological and reporting quality of existing systematic reviews on the subject.

METHODS

We first screened PubMed, EMBASE, and Cochrane Library databases for relevant literature and subjected the resulting articles to meta-analysis. We adopted the AMSTAR-2 and PRISMA checklists for assessing methodological and reporting quality, respectively, then performed meta-analyses to determine the relationship between incidence and mortality of three types of urinary cancers with obesity and overweight. Indirect comparisons were also done across subgroups.

RESULTS

All systematic reviews (SRs) were of critically low methodological quality. Seventeen SRs had minimal reporting flaws, and 11 SRs had minor reporting flaws. We found an association between obesity with an incidence of kidney (RR = 1.68, 95% CI 1.47-1.92), bladder (RR = 1.1, 95% CI 1.07-1.13), and prostate (RR = 1.02, 95% CI 0.91, 1.13) cancers. Similarly, overweight was associated with the incidence of the three types of cancer, recording RR values of 1.37 (95% CI 1.26-1.48), 1.07 (95% CI 1.03-1.1), and 1 (95% CI 0.93, 1.07) for kidney, bladder, and prostate cancers, respectively. With regard to the dose analysis, the RR of BMI (per 5 kg/m2 increase) was associated with kidney (RR = 1.24, 95% CI 1.2-1.28), bladder (RR = 1.03, 95% CI 1.02-1.05), and prostate (RR = 1.02, 95% CI 1.01, 1.03) cancers.

CONCLUSIONS

This comprehensive quantitative analysis provides an affirmation that overweight and obesity are strong risk factors for kidney cancer, owing to a strong association between them. Conversely, a weak association between overweight and obesity with bladder and prostate cancers confirms their status as mild risk factors for the 2 types of cancer. But due to the low quality of included SRs, the results need to be interpreted with caution.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019119459.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Epidemiology of Prostate Cancer

Prostate cancer is a major cause of disease and mortality among men, and each year 1.6 million men are diagnosed with and 366,000 men die of prostate cancer. In this review, we discuss the state of evidence for specific genetic, lifestyle, and dietary factors associated with prostate cancer risk. Given the biological heterogeneity of this cancer, we focus on risk factors for advanced or fatal prostate cancer. First, we provide descriptive epidemiology statistics and patterns for prostate cancer incidence and mortality around the world. This includes discussion of the impact of prostate-specific antigen screening on prostate cancer epidemiology. Next, we summarize evidence for selected risk factors for which there is strong or probable evidence of an association: genetics, obesity and weight change, physical activity, smoking, lycopene and tomatoes, fish, vitamin D and calcium, and statins. Finally, we highlight future directions for prostate cancer epidemiology research.

Body fatness at a young age and risks of eight types of cancer: systematic review and meta-analysis of observational studies

The associations between body fatness at a young age (childhood, adolescence and young adulthood; age ≤ 30 years) and diffuse large B-cell lymphoma (DLBCL), oesophageal adenocarcinoma, gastric cardia cancer, hepatocellular carcinoma, multiple myeloma, pancreatic cancer, renal cell cancer and thyroid cancer remain inconclusive. We performed a comprehensive systematic literature review and meta-analysis of observational studies to clarify the associations between body fatness at a young age and the risks of these cancers. PubMed and Web of Science databases were searched for relevant observational studies. Fifty-six articles yielded data on 27,559 cancer cases, including 3,170 DLBCL, 1,491 oesophageal adenocarcinoma, 1,103 gastric cardia cancer, 1,067 hepatocellular carcinoma, 3,090 multiple myeloma, 7,220 pancreatic cancer, 6,212 renal cell cancer and 4,206 thyroid cancer cases. Each 5 kg m^-2 increase in body mass index at a young age was positively associated with DLBCL (relative risk [RR] 1.21, 95% confidence interval [CI] 1.09, 1.35), oesophageal adenocarcinoma (RR 1.88, 95% CI 1.37, 2.57), gastric cardia cancer (RR 1.59, 95% CI 1.15, 2.21), hepatocellular carcinoma (RR 1.31, 95% CI 1.13, 1.51), multiple myeloma (RR 1.23, 95% CI 1.15, 1.30), pancreatic cancer (RR 1.17, 95% CI 1.11, 1.24), renal cell cancer (RR 1.22, 95% CI 1.16, 1.28) and thyroid cancer (RR 1.12, 95% CI 1.07, 1.17). In summary, higher body fatness at a young age increases the risks of developing various types of cancer later in life. Prevention of overweight and obesity in children, adolescents and young adults should therefore be emphasized to reverse the obesity epidemic and thereby avoid further increases in the burden of cancer attributed to excess body fatness.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Body fatness at an early age and risk of colorectal cancer

While there is convincing evidence that excess body fatness in adulthood is positively associated with colorectal cancer risk, the association between body fatness at an early age (≤30 years) and the risk of colorectal cancer has been equivocal. The present meta-analysis was performed to clarify this association. PubMed and Web of Science databases were searched for relevant studies that investigated this association. The risk estimates from each study were transformed into a continuous variable for each 5 kg/m² increase in body mass index (BMI). A random effects model was used to calculate the summary relative risks (RRs) with 95% confidence intervals (CIs). A total of 15 observational studies (13 cohort studies and two case-control studies) were included in this meta-analysis. Each 5 kg/m² increase in BMI was significantly associated with a 13% (RR 1.13, 95% CI 1.08, 1.19), 17% (RR 1.17, 95% CI 1.09, 1.25) and 8% (RR 1.08, 95% CI 1.04, 1.11) higher risk of colorectal cancer overall, in men, and in women, respectively. Substantial heterogeneity was observed across studies. Based on the anatomic subsite, each 5 kg/m² increase in BMI was significantly associated with a 14% (RR 1.14, 95% CI 1.07, 1.22) higher risk of colon cancer, whereas no association (RR 1.03, 95% CI 0.95, 1.13) was observed with rectal cancer. In summary, body fatness at an early age may affect colon cancer risk later in life. Prevention of overweight and obesity in young individuals should be emphasized to prevent early-onset colon cancer attributed to excess body fatness.

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

Background

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

Methods

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

Results

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

Conclusions

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

The use of measures of obesity in childhood for predicting obesity and the development of obesity-related diseases in adulthood: a systematic review and meta-analysis

BACKGROUND

It is uncertain which simple measures of childhood obesity are best for predicting future obesity-related health problems and the persistence of obesity into adolescence and adulthood.

OBJECTIVES

To investigate the ability of simple measures, such as body mass index (BMI), to predict the persistence of obesity from childhood into adulthood and to predict obesity-related adult morbidities. To investigate how accurately simple measures diagnose obesity in children, and how acceptable these measures are to children, carers and health professionals.

DATA SOURCES

Multiple sources including MEDLINE, EMBASE and The Cochrane Library were searched from 2008 to 2013.

METHODS

Systematic reviews and a meta-analysis were carried out of large cohort studies on the association between childhood obesity and adult obesity; the association between childhood obesity and obesity-related morbidities in adulthood; and the diagnostic accuracy of simple childhood obesity measures. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and a modified version of the Quality in Prognosis Studies (QUIPS) tool. A systematic review and an elicitation exercise were conducted on the acceptability of the simple measures.

RESULTS

Thirty-seven studies (22 cohorts) were included in the review of prediction of adult morbidities. Twenty-three studies (16 cohorts) were included in the tracking review. All studies included BMI. There were very few studies of other measures. There was a strong positive association between high childhood BMI and adult obesity [odds ratio 5.21, 95% confidence interval (CI) 4.50 to 6.02]. A positive association was found between high childhood BMI and adult coronary heart disease, diabetes and a range of cancers, but not stroke or breast cancer. The predictive accuracy of childhood BMI to predict any adult morbidity was very low, with most morbidities occurring in adults who were of healthy weight in childhood. Predictive accuracy of childhood obesity was moderate for predicting adult obesity, with a sensitivity of 30% and a specificity of 98%. Persistence of obesity from adolescence to adulthood was high. Thirty-four studies were included in the diagnostic accuracy review. Most of the studies used the least reliable reference standard (dual-energy X-ray absorptiometry); only 24% of studies were of high quality. The sensitivity of BMI for diagnosing obesity and overweight varied considerably; specificity was less variable. Pooled sensitivity of BMI was 74% (95% CI 64.2% to 81.8%) and pooled specificity was 95% (95% CI 92.2% to 96.4%). The acceptability to children and their carers of BMI or other common simple measures was generally good.

LIMITATIONS

Little evidence was available regarding childhood measures other than BMI. No individual-level analysis could be performed.

CONCLUSIONS

Childhood BMI is not a good predictor of adult obesity or adult disease; the majority of obese adults were not obese as children and most obesity-related adult morbidity occurs in adults who had a healthy childhood weight. However, obesity (as measured using BMI) was found to persist from childhood to adulthood, with most obese adolescents also being obese in adulthood. BMI was found to be reasonably good for diagnosing obesity during childhood. There is no convincing evidence suggesting that any simple measure is better than BMI for diagnosing obesity in childhood or predicting adult obesity and morbidity. Further research on obesity measures other than BMI is needed to determine which is the best tool for diagnosing childhood obesity, and new cohort studies are needed to investigate the impact of contemporary childhood obesity on adult obesity and obesity-related morbidities.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005711.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Childhood body weight in relation to morbidity from cardiovascular disease and cancer in older adulthood: 67-year follow-up of participants in the 1947 Scottish Mental Survey

Although it has been well documented that elevated body weight in middle- and older-aged populations is associated with multiple morbidities, the influence of childhood body weight on health endpoints other than coronary heart disease is not well understood. Accordingly, using a subsample of 4,620 participants (2,288 women) from the Scottish Mental Survey of 1947, we examined the association between body mass index measured at 11 years of age and future risk of 9 independent health endpoints as ascertained from national hospital admissions and cancer registers until 2014 (up to age 77 years). Although there was some evidence of a relationship between elevated childhood body mass index and higher rates of peripheral vascular disease (per each 1-standard deviation increase in body mass index, hazard ratio = 1.21, 95% confidence interval: 1.07, 1.37) and smoking-related cancers (per each 1-standard deviation increase in body mass index, hazard ratio = 1.09, 95% confidence interval: 1.01, 1.17), there was no apparent association with coronary heart disease, stroke (including ischemic stroke), heart failure, or carcinomas of the colorectum, stomach, lung, prostate, or breast. In conclusion, a relationship between childhood body weight and later morbidity was largely lacking in the present study.

Body size across the life course and prostate cancer in the Health Professionals Follow-up Study

Current evidence of an association between body size and prostate cancer is conflicting, possibly due to differential effects of body size across the lifespan and the heterogeneity of the disease. We therefore examined childhood and adult body size in relation to total incident prostate cancer and prognostic subtypes in a prospective cohort of 47,491 US men in the Health Professionals Follow-up Study. We assessed adult height, body mass index (BMI) in early and middle-to-late adulthood, adult waist circumference, and body shape at age 10. With follow-up from 1986 to 2010, we estimated the relative risk (RR) of prostate cancer using Cox proportional hazards models. We identified 6,183 incident cases. Tallness was associated with increased risk of advanced-stage tumors, particularly fatal disease (RR = 1.66, 95% CI 1.23-2.23, highest vs. lowest quintile, ptrend < 0.001). High BMI at age 21 was inversely associated with total prostate cancer (RR = 0.89, 95% CI 0.80-0.98, BMI ≥ 26 vs. 20-21.9, ptrend = 0.01) and with fatal and advanced disease. The association for late adult BMI differed by age (pinteraction < 0.001); high BMI was inversely associated with total prostate cancer (RR = 0.64, 95% CI 0.51-0.78, BMI ≥ 30 vs. 21-22.9, ptrend <0.001) and with non-advanced and less aggressive tumors among men ≤ 65 years, whereas no association was seen among men >65 years. Adult waist circumference was weakly inversely associated with less aggressive disease. Childhood obesity was unclearly related to risk. Our study confirms tall men to be at increased risk of fatal and advanced prostate cancer. The influence of adiposity varies by prognostic disease subtype and by age. The relationship between body size and prostate cancer is complex. Body size changes progressively throughout life and consequent effects on prostate cancer risk may be associated with related changes in hormonal and metabolic pathways. This large prospective study examined potential associations between the risk of various prostate cancer subtypes and multiple anthropometric measures at different ages in men. Tallness was confirmed to be associated with an elevated risk of advanced prostate cancer, particularly fatal disease. The extent to which body weight influenced risk varied according to factors such as age and disease subtype.

Preschoolers in the Playground: a pilot cluster randomised controlled trial of a physical activity intervention for children aged 18 months to 4 years

Background

The preschool years are considered critical for establishing healthy lifestyle behaviours such as physical activity. Levels of physical activity track through childhood into adulthood and establishing habitual physical activity early in life is therefore vital. Time spent outdoors is associated with greater physical activity and playground interventions have been shown to increase physical activity in school-aged children. There are few preschool, playground-based interventions and these have given inconclusive results. A report published by the UK’s Chief Medical Officer (CMO) highlighted the need for new interventions to promote movement in the early years (0–5 years).

Objectives

This study aimed to undertake a pilot cluster randomised controlled trial (RCT) of an outdoor playground-based physical activity intervention for parents and their children aged from 18 months to 4 years (Preschoolers in the Playground or PiP) and to assess the feasibility of conducting a full-scale cluster RCT.

Design

The study was a two-armed pilot cluster RCT with economic and qualitative evaluations. Participants were randomised on a 1 : 1 basis to the PiP intervention (n = 83) or usual practice (control;n = 81).

Setting

Bradford, West Yorkshire, UK.

Participants

Children aged from 18 months to 4 years.

Intervention

The PiP intervention is grounded in behavioural theory (social cognitive theory) and is in accordance with CMO guidance for physical activity in the early years. It is informed by existing literature and data collected from focus groups with parents. The intervention was delivered in primary school playgrounds. Six 30-minute PiP sessions per week were available for 30 weeks; families were encouraged to come to three a week. The 10-week initiation phase was facilitated by a member of school staff and the maintenance phase was unsupervised.

Main outcome measures

Recruitment and retention of schools and families to the trial were the main outcome measures. The acceptability of trial procedures and the intervention, the feasibility of collecting health outcome data and the fidelity of the implementation of the intervention were also evaluated. A preliminary assessment of cost-effectiveness and a sample size calculation for a full trial were conducted.

Results

In total, 37% of schools and 48% of parents approached agreed to take part. Levels of retention were good at 10 and 52 weeks’ follow-up (82.3% and 83.5% respectively). Both the trial procedures and the intervention were acceptable. However, attendance was low during the autumn and winter/spring initiation phases but somewhat better in the summer initiation phase. Attendance was poor throughout all maintenance phases. The accelerometry protocol for measuring physical activity requires modification. The fidelity of intervention implementation was good (81% adherence). The intervention was borderline cost-effective. A sample size of 600 children from 38 schools is required for a full trial.

Conclusion

A full RCT of the PiP intervention is feasible. The PiP intervention requires some modification, for example running the intervention during the summer term only, but was found to be acceptable to schools and families.

Trial registration

Current Controlled Trials ISRCTN54165860.

Funding

This project was funded by the NIHR Public Health Research programme and will be published in full inPublic Health Research; Vol. 3, No. 5. See the NIHR Journals Library website for further project information.

Obesity and Prostate Cancer Risk According to Tumor TMPRSS2:ERG Gene Fusion Status

The T2E gene fusion, formed by fusion of the transmembrane protease, serine 2, gene (TMPRSS2) with the erythroblast transformation-specific (ETS)-related gene (ERG), is found in approximately 50% of prostate cancers and may characterize distinct molecular subtypes of prostate cancer with different etiologies. We investigated the relationship between body mass index (BMI; weight (kg)/height (m)(2)) and prostate cancer risk by T2E status. Study participants were residents of King County, Washington, recruited for 2 population-based case-control studies conducted in 1993-1996 and 2002-2005. Tumor T2E status was determined for 563 prostate cancer patients who underwent radical prostatectomy. Information on weight, height, and covariables was obtained through in-person interviews. We performed polytomous logistic regression to calculate odds ratios and 95% confidence intervals for T2E-positive and -negative prostate cancer. Comparing the highest BMI quartile with the lowest, inverse associations were observed between recent (≥29.7 vs. <24.5: odds ratio = 0.66, 95% confidence interval: 0.45, 0.97) and maximum (≥31.8 vs. <25.9: odds ratio = 0.69, 95% confidence interval: 0.47, 1.02) BMI and the risk of T2E-positive prostate cancer. No significant associations were seen for men with T2E-negative tumors. This study provides evidence that obesity is specifically associated with reduced risk of developing androgen-responsive T2E fusion-positive tumors. The altered steroid hormone profile in obese men may contribute to this inverse association.

Dual burden of body weight among Iranian children and adolescents in 2003 and 2010: the CASPIAN-III study

INTRODUCTION

Our aim was to compare changes of body mass index (BMI) and waist circumference (WC) curves of Iranian children by comparing the results of two national surveys of a surveillance program, i.e. CASPIAN-I (2003-2004) and CASPIAN-III (2009-2010). The second objective was to evaluate the prevalence of obesity, overweight and underweight among 10-18-year-old Iranian children and adolescents.

MATERIAL AND METHODS

This study was performed among students who were selected by multistage random cluster sampling from urban and rural areas of 27 provinces of Iran, as part of a national survey of school student high risk behavior entitled CASPIAN-III, conducted in 2009-2010.

RESULTS

We evaluated 5088 school students (50.2% boys). In rural areas, underweight was more common in boys and overweight and obesity in girls. In urban areas underweight and obesity were more common in boys, whereas overweight was more common in girls. The highest prevalence of underweight (23.5%) was seen in students aged 13 years and the lowest (11.4%) in those aged 18 years. Underweight was significantly more common in rural than in urban areas (22.1% vs. 15.8%, respectively, p < 0.0001) and overweight/obesity was more common in urban than in rural areas. Compared with the findings in 2003-2004, the overall prevalence of elevated body mass index (16.6%) including obesity (9.1%) and overweight (7.5%) as well as underweight (17.5%) increased from 2003 to 2010.

CONCLUSIONS

In recent years, the double burden of nutritional disorders has increased among Iranian children and adolescents, especially in rural areas. This change may be related to epidemiologic transition, notably in terms of nutrition transition and rapid changes in lifestyle habits. This finding is an important issue for policy-makers for interventional preventive programs.

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.

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

Although the contribution of lifestyle and environment (non-genetic factors) to prostate carcinogenesis is indicated by international variation in prostate cancer occurrence and migration studies, no conclusive modifiable risk factors have yet been identified. One possible reason for this may be the dearth of epidemiological research on exposures experienced early in life, when the immature prostate may be more susceptible to carcinogenic exposures. In this Opinion article, we summarize the rationale for studying early-life exposures, describe the small body of early-life research and its associated challenges, and point to solutions for future research.

Lifestyle and dietary factors in the prevention of lethal prostate cancer

The prevention of lethal prostate cancer is a critical public health challenge that would improve health and reduce suffering from this disease. In this review, we discuss the evidence surrounding specific lifestyle and dietary factors in the prevention of lethal prostate cancer. We present a summary of evidence for the following selected behavioral risk factors: obesity and weight change, physical activity, smoking, antioxidant intake, vitamin D and calcium, and coffee intake.

Association of body mass index in early adulthood and middle age with future site-specific cancer mortality: the Harvard Alumni Health Study

BACKGROUND

The association between adiposity in early adulthood and subsequent development of specific malignancies is unclear. Further, the potential for mediation by adiposity in middle age has not been well examined. In a rare study, we investigated the association of body mass index (BMI) in early adulthood with mortality from several site-specific cancers.

DESIGN

In the Harvard Alumni Health Study cohort, 19 593 males had a physical examination at the university between 1914 and 1952 (mean age: 18.4 years) and returned a questionnaire in 1962 or 1966 (mean age = 45.1 years). BMI was computed using weight (kg)/height(2) (m(2)) at both time points. Vital status follow up continued for a maximum of 82 years.

RESULTS

Positive early adulthood cancer mortality gradients by BMI were found for all malignancies combined (adjusted hazard ratio [HR] = 1.11; 95% confidence interval [CI]: 1.05-1.17 for a one standard deviation increase in early adulthood BMI), and for lung (HR = 1.24; 95% CI = 1.10-1.40) and skin (HR = 1.29; 95% CI = 0.96-1.75) cancers. There were also apparent associations for cancers of the oesophagus and urogenital sites. Mediation by BMI in middle age was found to be minimal.

CONCLUSION

Higher BMI in early adulthood appears to be a direct risk factor for selected malignancies several decades later.

The metabolic syndrome and risk of prostate cancer in Italy

PURPOSE

To provide information on the role of the metabolic syndrome on prostate cancer risk.

METHODS

We examined data from a multicentric Italian case-control study. Cases were 1294 patients with incident, histologically confirmed prostate cancer. Controls were 1451 men hospitalized with acute, non-neoplastic conditions. All subjects were younger than 75 years. The metabolic syndrome was defined according to selected indicators of abdominal obesity, hypercholesterolemia, hypertension, and diabetes. We computed multivariate odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression.

RESULTS

Considering separate components of the metabolic syndrome, the ORs were 0.98 (95% CI, 0.72-1.34) for diabetes, 1.14 (95% CI, 0.96-1.36) for hypertension, 1.54 (95% CI, 1.26-1.89) for hypercholesterolemia, and 1.02 (95% CI, 0.86-1.21) for abdominal obesity. The OR of prostate cancer was 1.66 (95% CI, 1.22-2.28) in men with metabolic syndrome compared with those without. We found ORs of 1.02 (95% CI, 0.83-1.26) for men with one component of the metabolic syndrome, 1.12 (95% CI, 0.89-1.42) for two, 1.65 (95% CI, 1.15-2.36) for three, and 3.99 (95% CI, 1.03-15.4) for four compared with no components.

CONCLUSIONS

The metabolic syndrome was associated with the risk of prostate cancer in this population.

Altered xanthine oxidase and N-acetyltransferase activity in obese children

AIMS

It is well established that oxidative and conjugative enzyme activity differs between obese and healthy-weight adults. However, the effect of obesity on drug metabolism in children has not been studied extensively. This study examined whether obese and healthy-weight children vary with respect to oxidative enzyme activity of CYP1A2, xanthine oxidase (XO) and conjugative enzyme activity of N-acetyltransferase 2 (NAT2).

METHODS

In vivo CYP1A2, XO and NAT2 activity was assessed in obese (n= 9) and lean (n= 16) children between the ages of 6-10 years using caffeine (118.3 ml Coca Cola®) as probe. Urine samples were collected in 2-h increments over 8 h. Caffeine and metabolites were measured using LC/MS, and urinary metabolic ratios were determined based on reported methods.

RESULTS

Sixteen healthy-weight and nine obese children were evaluated. XO activity was elevated in paediatric obese volunteers compared with non-obese paediatric volunteers (XO metabolic ratio of 0.7 ± 0.06 vs. 0.6 ± 0.06, respectively, 95% CI 0.046, 0.154, P < 0.001). NAT2 activity was fivefold higher in the obese (1 ± 0.4) as compared with non-obese children (0.2 ± 0.1), 95% CI 0.26, 1.34, P < 0.05. However, no difference was observed in CYP1A2 activity between the groups (95% CI -2.72, 0.12, P > 0.05).

CONCLUSIONS

This study provides evidence that obese children have elevated XO and NAT2 enzyme activity when compared with healthy-weight controls. Further studies are needed to determine how this may impact the efficacy of therapeutic agents that may undergo metabolism by these enzymes.

Associations of birth weight and physical activity with sex steroids in preschool Japanese children

PURPOSE

We aimed to assess the association of body size at birth or physical activity with sex steroid levels, independent of body mass among young children.

METHODS

The cross-sectional study was conducted in 2006. Subjects were 230 boys and 198 girls, aged 3-6 years. Birth weight was based on parents' reports. Questions about physical activity focused on outdoor playtime. Urinary estrone, estradiol, testosterone, and 5-androstene-3β,17α diol (3β,17α-AED) levels were measured by liquid chromatography-electrospray ionization tandem mass spectrometry. Urinary dehydroepiandrosterone level was measured with a radioimmunoassay.

RESULTS

After adjustments for age and BMI, girls with lower birth weight had higher testosterone (trend p = 0.038) and 3β,17α-AED (trend p = 0.028). Girls with low birth weight and high birth weight had higher estrone (p = 0.014) and estradiol (p = 0.074) than those who had middle birth weight. Boys who were physically active had lower testosterone (p = 0.028) and 3β,17α-AED (p = 0.003) than those who were not active. Girls who were physically active had lower estrone (p = 0.015).

CONCLUSIONS

Sex steroid levels in childhood might be affected by body size at birth or by physical activity during childhood. These effects might differ by sex.

Body mass index, prostate cancer-specific mortality, and biochemical recurrence: a systematic review and meta-analysis

Increasing evidence suggested obesity, measured by body mass index (BMI), was associated with prostate cancer-specific mortality, and its impact on biochemical recurrence was also inconclusive. We systematically searched MEDLINE, EMBASE, and bibliographies of retrieved studies up to January 5, 2010. We used random-effects meta-analysis to assess the relative risks (RR) of prostate cancer-specific mortality and biochemical recurrence associated with a 5 kg/m(2) increase in BMI. Among the six population-based cohort studies in 1,263,483 initially cancer-free men, 6,817 prostate cancer deaths occurred; a 5 kg/m(2) increase in BMI was associated with 15% (RR: 1.15, 95% confidence interval (CI): 1.06-1.25, P < 0.01) higher risk of dying of prostate cancer. In the six postdiagnosis survival studies on 18,203 patients with 932 prostate cancer deaths, a 5 kg/m(2) increase in BMI was associated with 20% higher prostate cancer-specific mortality (RR: 1.20, 95% CI: 0.99-1.46, P = 0.06). In the sixteen studies which followed 26,479 prostate cancer patients after primary treatment, a 5 kg/m(2) increase in BMI was significantly associated with 21% increased risk of biochemical recurrence (RR: 1.21, 95% CI: 1.11-1.31 P < 0.01). Elevated BMI is associated with risk of prostate cancer-specific mortality in prospective cohort studies and biochemical recurrence in prostate cancer patients. Its association with prostate cancer-specific mortality in diagnosed patients needs to be further evaluated.

Relationship of body mass, height, and weight gain to prostate cancer risk in the multiethnic cohort

We investigated the relationship of body size and prostate cancer risk in the Multiethnic Cohort, a longitudinal study of individuals ages 45 to 75 in Hawaii and in California. Self-reported measures of height and weight were obtained at baseline. Of 83,879 men enrolled from 1993 to 1996, a total of 5,554 were diagnosed with prostate cancer during an average of 9.6 years of follow-up. The influence of baseline weight and weight change since age 21 varied by ethnic group. Whites gaining more than 10 lbs had a nonlinear, increased risk of advanced and high-grade prostate cancer [relative risks (RR), 2.12; 95% confidence intervals (CI), 1.19-3.78 for 25-39.9 lbs; P trend 0.43; and RR, 1.49; 95% CI, 1.04-2.14, for >or=40 lbs; P trend 0.20, respectively]. African American men gaining 40 lbs or more (relative to <10 lbs) had a nonmonotonic, increased risk of localized prostate cancers (RR, 1.26; 95% CI, 1.02-1.54; P trend 0.09) and those who gained 25 lbs or more were at increased risk of low-grade disease (RR, 1.28; 95% CI, 1.03-1.58, for >or=40 versus 10 lbs, respectively; P trend 0.07). Japanese men had a statistically significant, inverse association of weight gain and localized disease (RR, 0.80; 95% CI, 0.65-0.99 for >or=40 versus 10 lbs; P trend 0.05). Our findings provide evidence that adiposity and changes in adiposity between younger and older adulthood influence the development of prostate cancer. Ethnic differences in risk may be explained by variation in the distribution of accumulated body fat that could differentially affect prostate carcinogenesis.