Body mass index in young adulthood and cancer mortality: a retrospective cohort study

Childhood overweight and obesity and the risk of depression across the lifespan

BACKGROUND

Obesity has been longitudinally associated with depression but only few studies take a life course approach. This longitudinal study investigates whether being overweight or obese at age 8 and 13 years is associated with depressive symptoms more than 60 years later and whether this association is independent of late-life body mass index (BMI). We also investigated the association of being overweight/obese at age 8 or 13 years with ever having major depressive disorder (lifetime MDD).

METHOD

This analysis is based on a sub-sample of 889 AGES-Reykjavik participants with measured BMI data from early life. Late-life depressive symptoms were measured with the Geriatric Depression Scale (GDS) and lifetime MDD was assessed at late-life using the Mini International Neuropsychiatric Interview. Logistic regression analysis was used to estimate the relationships between BMI (continuous and categorical) at age 8 or 13 years, and late-life depressive symptoms (measured as GDS ≥ 5) or lifetime MDD, adjusted for sex, education, physical activity, smoking status and alcohol use. In a separate model, additional adjustments were made for late-life BMI.

RESULTS

One hundred and one subjects (11%) had depressive symptoms at late-life (GDS ≥ 5), and 39 subjects (4.4%) had lifetime MDD. Being overweight or obese at age 8 or 13 years was not associated with higher depressive symptoms during late-life, irrespective of late-life BMI. Being overweight or obese at age 8 years, but not age 13 years was associated with an increased risk of lifetime MDD (Odds Ratio (OR) (95% confidence interval [CI]) for age 8 = 4.03[1.16-13.96]P = 0.03 and age 13 = 2.65[0.69-10.26] P = 0.16, respectively).

CONCLUSION

Being overweight in childhood was associated with increased odds of lifetime MDD, although the magnitude of the risk is uncertain given the small numbers of participants with lifetime MDD. No clear association was observed between childhood and adolescent overweight/obesity and late-life depressive symptoms irrespective of late life BMI.

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

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

Being overweight in early adulthood is associated with increased mortality in middle age

Observational analyses of the association between body mass index (BMI) and all-cause mortality often suggest that overweight is neutral or beneficial, but such analyses are potentially confounded by smoking or by reverse causation. The use of BMI measured in early adulthood offers one means of reducing the latter problem. We used a cohort who were first measured while 16-24 year old students at Glasgow University in 1948-1968 and subsequently re-measured in 2000-2003, offering a rare opportunity to compare BMI measured at different ages as a predictor of mortality. Analysis of the later BMI measurements suggested that overweight was beneficial to survival, while analysis of BMI measured in early adulthood suggested that overweight was harmful and that the optimum BMI lay towards the lower end of the recommended range of 18.5-25 kg m^-2. We interpret the association with later BMI as being probably distorted by reverse causality, although it remains possible instead that the optimum BMI increases with age. Differences when analyses were restricted to healthy non-smokers also suggested some residual confounding by smoking. These results suggest that analyses of BMI recorded in middle or old age probably over-estimate the optimum BMI for survival and should be treated with caution.

Adolescent body mass index and erythrocyte sedimentation rate in relation to colorectal cancer risk

OBJECTIVE

Adult obesity and inflammation have been associated with risk of colorectal cancer (CRC); however, less is known about how adolescent body mass index (BMI) and inflammation, as measured by erythrocyte sedimentation rate (ESR), relate to CRC risk. We sought to evaluate these associations in a cohort of 239 658 Swedish men who underwent compulsory military enlistment examinations in late adolescence (ages 16-20 years).

DESIGN

At the time of the conscription assessment (1969-1976), height and weight were measured and ESR was assayed. By linkage to the national cancer registry, these conscripts were followed for CRC through 1 January 2010. Over an average of 35 years of follow-up, 885 cases of CRC occurred, including 501 colon cancers and 384 rectal cancers. Cox regression was used to estimate adjusted HRs and corresponding 95% CIs.

RESULTS

Compared with normal weight (BMI 18.5 to <25 kg/m(2)) in late adolescence, upper overweight (BMI 27.5 to <30 kg/m(2)) was associated with a 2.08-fold higher risk of CRC (95% CI 1.40 to 3.07) and obesity (BMI 30+ kg/m(2)) was associated with a 2.38-fold higher risk of CRC (95% CI 1.51 to 3.76) (p-trend: <0.001). Male adolescents with ESR (15+ mm/h) had a 63% higher risk of CRC (HR 1.63; 95% CI 1.08 to 2.45) than those with low ESR (<10 mm/h) (p-trend: 0.006). Associations did not significantly differ by anatomic site.

CONCLUSIONS

Late-adolescent BMI and inflammation, as measured by ESR, may be independently associated with future CRC risk. Further research is needed to better understand how early-life exposures relate to CRC.

Anthropometric Measures at Multiple Times Throughout Life and Prostate Cancer Diagnosis, Metastasis, and Death

BACKGROUND

Previous studies of prostate cancer (PCa) risk and anthropometrics (ie, body measurements) were based on single measurements or obtained over limited time spans.

OBJECTIVE

To study the association between anthropometrics measured at multiple time points in life and their relation to later diagnosis, metastasis, or death from PCa.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study includes 27 167 Swedish men enrolled in two population-based projects from 1974 to 1996. PCa diagnosis up to December 31, 2006, disease information, gestation time, and anthropometrics at birth, military conscript testing, and adulthood were collected. A total of 1355 PCa cases were matched with 5271 controls.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Univariate conditional logistic regression was used to determine whether clinical diagnosis, metastasis, or PCa death was associated with low birth weight (weight <2500 g); with small size for gestational age; or with weight, length, or body mass index (BMI) at birth, adolescence (aged 16-22 yr), or early middle age (aged 44-50 yr).

RESULTS AND LIMITATIONS

Apart from weight at adolescence, which was associated with an increased risk of PCa diagnosis (odds ratio [OR] per 5 kg: 1.05; 95% confidence interval [CI], 1.01-1.09; p=0.026), preadulthood measurements were not associated with any PCa end point. Adulthood parameters were not associated with diagnosis. In contrast, weight and BMI at early middle age were significantly associated with metastasis (OR per 5 kg: 1.13; 95% CI, 1.06-1.20; p<0.0001, and OR: 1.09; 95% CI, 1.05-1.14; p<0.0001) and death (OR per 5 kg: 1.11 (95% CI, 1.03-1.19; p=0.005, and OR: 1.08; 95% CI, 1.03-1.13; p=0.003), respectively. It remains unclear whether these results apply to men of nonwhite origin, to populations with active PCa screening programs, or to countries without socialized health care.

CONCLUSIONS

The analyses of these large data sets demonstrate that significant effects of body characteristics (with links to metabolic syndrome) measured at early middle age are associated with PCa disease severity, metastatic progression, and outcome. Conversely, measurements at birth and adolescence are not associated with PCa prevalence or outcome.

PATIENT SUMMARY

Increased weight and body mass index in adults is associated with a higher risk of prostate cancer metastasis and death.

Early life body fatness and risk of colorectal cancer in u.s. Women and men-results from two large cohort studies

BACKGROUND

The association between body fatness before adulthood and later risk of colorectal cancer remains unclear. We hypothesized that, independent of adult body fatness, early life body fatness would be associated with a higher risk of developing colorectal cancer.

METHODS

We assessed body fatness during childhood and adolescence using a validated 9-level somatotype and inquired body weight in young adulthood in the Nurses' Health Study and Health Professionals Follow-up Study. We used the Cox proportional hazard regression modeling to estimate relative risks [RR, 95% confidence intervals (CI)] adjusting for adult body mass index (BMI) and other known colorectal cancer risk factors.

RESULTS

We identified 2,100 incident colorectal cancer cases (1,292 in women and 808 in men) during 22 years of follow-up. Among women, the RR (95% CI) for childhood body fatness of level 5 or higher versus level 1 was 1.28 (1.04-1.58; Ptrend = 0.08) and for adolescent body fatness, it was 1.27 (1.01-1.60; Ptrend = 0.23). The corresponding RRs for men were 1.04 (0.82-1.31; Ptrend = 0.48) and 0.98 (0.75-1.27; Ptrend = 0.20), respectively. Results were generally similar across anatomic subsites within the colorectum. In addition, the RRs comparing BMI categories ≥27.5 to <19 kg/m(2) were 1.44 (1.06-1.95, at age 18; Ptrend = 0.009) for women and 1.18 (0.84-1.65, at age 21; Ptrend = 0.57) for men.

CONCLUSION

Increased body fatness in early life, independent of adult obesity, might be a risk factor for colorectal cancer in women, but we observed a weaker association in men.

IMPACT

Our findings support the growing evidence that early life body fatness affects the risk of colorectal cancer many decades later.

Associations of physical activity and inactivity with body tissue composition among healthy Polish women and women after mastectomy

The aim of the study is to determine the relationship between physical activity and body composition among healthy women and women who have had mastectomy. This is in order to establish whether physical activity of women after breast cancer treatment improves composition and distribution of body mass components to a degree which will allow to achieve the body composition of healthy women. Research material consists of anthropometric measurements (body height, weight) of women and bioelectric impedance analysis (BIA) of body composition (using Akern - BIA 101 composition analyzer). Intensity of activity was assessed using the Physical Activity International Questionnaire. The sample consisted of 76 healthy women (active 44.74%, inactive 55.26%) and 70 females after mastectomy (54.29% and 45.71%, respectively). Mean chronological age of women after mastectomy was 53.40 years, SD=7.55, and of the healthy ones 52.38 years SD=11.01). A significant difference in body composition was noted among active and inactive women after mastectomy; namely the active females had lower weight (by approximately 12 kg), body mass index (BMI), level of fat mass (by approximately 8%) and (by approximately 5%) total body water. The active healthy women had 6% less fat mass, almost 4% more body water and 6% more fat free mass. Programmed physical activity undertaken by women after mastectomy is recommended and produces good results in the form of reduction of excessive body fat tissue. Through physical activity these women are able to achieve the same level of fat mass as healthy women.

Weight status in young adulthood and survival after cardiovascular diseases and cancer

BACKGROUND

Some studies have suggested that overweight is associated with lower mortality, but these results may be affected by reverse causality. We analysed how body mass index (BMI) in young adulthood is associated with mortality in the general population and after the diagnoses of coronary heart disease (CHD), stroke and cancer.

METHODS

BMI was measured at an average age of 18 years in 734 438 Swedish men born in 1950-65. Diagnoses of CHD, stroke and cancer as well as all-cause mortality were derived from registers covering the whole population, up to 31 December 2010. The follow-up of 24.56 million person-years included 33 067 cases of mortality and 19 843 CHD, 13 578 stroke and 27 365 cancer diagnoses. Hazard ratios (HR) [with 95% confidence intervals (CI)] were estimated by the Cox proportional hazards model.

RESULTS

Higher mortality in the whole cohort (HR = 1.26, 1.21-1.32) as well as after the diagnosis of CHD (HR = 1.33, 1.09-1.63) or cancer (HR = 1.13, 1.01-1.25) was found in moderately overweight men (BMI 25.0-27.4 kg/m(2)) as compared with normal weight men (BMI 20.1-22.4 kg/m(2)); for stroke patients the result for the same BMI categories was not statistically significant (HR = 1.17, 0.94-1.45). Mortality increased with increasing weight status and was highest in obese men (BMI >30 kg/m(2)): HR = 2.17 (2.02-2.34) for the whole cohort, 2.35 (1.81-3.05) after the diagnosis of CHD, 2.08 (1.56-2.77) after stroke and 1.68 (1.40-2.01) after cancer.

CONCLUSIONS

Even moderate overweight in young adulthood increases all-cause mortality and mortality after the diagnosis of CHD, stroke and cancer in men. Preventing overweight in young adulthood remains as an important public health issue.

Hypertension, obesity and prostate cancer biochemical recurrence after radical prostatectomy

BACKGROUND

The metabolic syndrome (MetS) comprises a constellation of risk factors associated with an increased risk for cardiovascular disease. Components of MetS have emerged as putative risk factors for prostate carcinoma. In this study, we examine the association between three features of the MetS (obesity, hypertension and diabetes) and the risk of biochemical recurrence (BCR) after radical prostatectomy (RP).

METHODS

We examined data from 1428 men in the University of Michigan Prostate Cancer Data Bank who elected to have RP as their primary treatment. We calculated body mass index from patients' weight and height measured at the time of prostate cancer diagnosis. We used the University of Michigan's Electronic Medical Record Search Engine to identify subjects with hypertension and/or diabetes before their prostate cancer diagnosis.

RESULTS

Of 1428 men who underwent RP, 107 (8%) subsequently developed BCR with a median length of follow-up post-surgery of 3.6 years. Obesity and hypertension were each associated with an increased risk of BCR (adjusted hazard ratio (aHR) = 1.37; 95% CI 0.92-2.09 and aHR = 1.51, 95% CI 1.01-2.26), whereas no association was observed between diabetes and BCR (aHR = 0.73; 95% CI 0.40-1.33).

CONCLUSIONS

Obesity and hypertension were each associated with an increased risk for BCR of prostate cancer after RP, independent of age at diagnosis and tumor pathological features. Given the increasing rates of obesity, hypertension and prostate cancer, a better understanding of the relationship between these entities is of significant public health importance. Elucidation of the involved pathogenic mechanisms will be needed to establish causality.

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.

Body mass index and death rate of colorectal cancer among a national cohort of U.S. adults

Substantial evidence suggests that increasing adiposity is associated with an increased death rate of colorectal cancer, but no studies were conducted among national representative populations in the United States. The current study examined the death rate across BMI levels in 7,016 adults who participated in the National Health and Nutrition Examination Survey in 1971-1975. BMI categories were defined as normal (18.5-24.9 kg/m(2)), overweight (25-29.9), and obese (≥30). A total of 519 cancer deaths were identified during a 17-yr follow-up with 118,998 person-years. No significantly increased death rates of total cancers, lung, breast, and prostate cancer were observed among participants with an increased BMI. However, colorectal cancer death rates were 0.39, 0.68, and 0.96/1,000 person-years, respectively, for normal weight, overweight, and obese (P value for log-rank trend test < 0.001), and the corresponding adjusted hazard ratios [95% confidence intervals (CI)] were 1.00 (reference), 1.25 (95% CI = 0.72-2.19), and 2.04 (1.08-3.83), respectively. No gender difference of the association was identified. The authors conclude that a significantly increased death rate of colorectal cancer was associated with excess body weight. The current study is an addition to the expanding body of literature indicating an increased risk of colorectal cancer development among the obese.

Body fatness during childhood and adolescence, adult height, and risk of colorectal adenoma in women

The latest report by the World Cancer Research Fund/American Institute of Cancer Research concluded that there is convincing evidence that adult height and obesity are risk factors for colorectal cancer. However, studies relating body fatness during early life to the risk of colorectal cancer or adenoma are scarce. In the Nurses' Health Study II, participants recalled adult attained height and body shape at ages 5, 10, and 20 years (using a 9-level pictogram: 1 = most lean body shape, 9 = most overweight body shape) at baseline. Among 32,707 women who had at least one lower bowel endoscopy between 1991 and 2005, 2,327 colorectal adenomas were documented. Adult height was positively associated with risk of colorectal adenoma (multivariate OR per 2 inch increment 1.05, 95% CI: 1.01-1.09). Comparing women who were overweight (body shape level 6 or higher) to women who were most lean (body shape level 1), ORs (95% CI, P(trend)) of colorectal adenoma for body shapes at ages 5, 10, and 20 years were 1.44 (1.04-1.99, 0.01), 1.21 (0.93-1.56, 0.05), and 1.03 (0.74-1.42, 0.58), respectively. Adjustment for adult body mass index did not change results substantially. The positive associations for body fatness at ages 5 and 10 years as well as adult height were restricted to distal adenoma, while not seen for proximal or rectal adenoma. Higher height and body fatness during childhood was associated with increased risk of distal adenoma later in life, independent of adult body weight.

Body mass index in early and middle-late adulthood and risk of localised, advanced and fatal prostate cancer: a population-based prospective study

BACKGROUND

The relationships between body mass index (BMI) during early and middle-late adulthood and incidence of prostate cancer (PCa) by subtype of the disease (localised, advanced) and fatal PCa is unclear.

METHODS

A population-based cohort of 36,959 Swedish men aged 45-79 years was followed up from January 1998 through December 2008 for incidence of PCa (1530 localised and 554 advanced cases were diagnosed) and through December 2007 for PCa mortality (225 fatal cases).

RESULTS

From a competing-risks analysis, incidence of localised PCa was observed to be inversely associated with BMI at baseline (middle-late adulthood; rate ratio (RR) for 35 kg m(-2) when compared with 22 kg m(-2) was 0.69 (95% CI 0.52-0.92)), but not at age 30. For fatal PCa, BMI at baseline was associated with a nonstatistically significant increased risk (RR for every five-unit increase: 1.12 (0.88-1.43)) and BMI at age 30 with a decreased risk (RR for every five-unit increase: 0.72 (0.51-1.01)).

CONCLUSION

Our results indicate an inverse association between obesity during middle-late, but not early adulthood, and localised PCa. They also suggest a dual association between BMI and fatal PCa--a decreased risk among men who were obese during early adulthood and an increased risk among those who were obese during middle-late adulthood.

The association of body mass index with mortality in the California Teachers Study

Although underweight and obesity have been associated with increased risk of mortality, it remains unclear whether the associations differ by hormone therapy (HT) use and smoking. The authors examined the relationship between body mass index (BMI) and mortality within the California Teachers Study (CTS), specifically considering the impact of HT and smoking. The authors examined the associations of underweight and obesity with risks of all-cause and cause-specific mortality, among 115,433 women participating in the CTS, and specifically examined whether HT use or smoking modifies the effects of obesity. Multivariable Cox proportional hazards regression provided estimates of relative risks (RRs) and 95% confidence intervals (CIs). During follow up, 10,574 deaths occurred. All-cause mortality was increased for underweight (BMI <18.5; adjusted RR = 1.33, 95% CI = 1.20-1.47) and obese participants (BMI ≥ 30: RR = 1.27, 95% CI = 1.19-1.37) relative to BMI of 18.5-24.9). Respiratory disease mortality was increased for underweight and obese participants. Death from any cancer, and breast cancer specifically, and cardiovascular disease was observed only for obese participants. The obesity and mortality association remained after stratification on HT and smoking. Obese participants remained at greater risk for mortality after stratification on menopausal HT and smoking. Obesity was associated with increased all-cause mortality, as well as death from any cancer (including breast), and cardiovascular and respiratory diseases. These findings help to identify groups at risk for BMI-related poor health outcomes.

Prostate cancer gene expression signature of patients with high body mass index

The goal of this study was to evaluate prostate cancer gene expression signatures associated with elevated body mass index (BMI). Global gene expression profiles of prostate tumor cells and matching normal epithelial cells were compared between patients with features of normal- and high BMI at the time of radical prostatectomy. Knowledge-based analyses revealed an association of high BMI with altered levels of lipid metabolism and cholesterol homeostasis genes, such as stearoyl-CoA desaturase 1 (SCD1) and insulin-induced gene 1 (INSIG1), respectively, in prostate tumor cells. These genes were connected to known pathways of tumorigenesis revealed by the v-maf (musculoaponeurotic fibrosarcoma) oncogene homolog (MAF), notch receptor ligand, jagged 1 (JAG1), and the alanyl aminopeptidase (ANPEP/CD13) genes. This study highlighted that SCD1, a known target of statins, may play a mechanistic role in the recently noted beneficial effects of statin treatment in reducing biochemical recurrence of prostate cancer. An additional finding of our study is that some of the obesity related genes were upregulated in tumor-matched normal cells within the high BMI group, when compared to normal cells within the normal BMI cohort.

Long-term impact of overweight and obesity in childhood and adolescence on morbidity and premature mortality in adulthood: systematic review. Int J Obes (Lond). 2011;35:891-898. [PMID: 20975725 DOI: 10.1038/ijo.2010.222]

BACKGROUND AND OBJECTIVE

The last systematic review on the health consequences of child and adolescent obesity found little evidence on consequences for adult health. The present study aimed to summarize evidence on the long-term impact of child and adolescent obesity for premature mortality and physical morbidity in adulthood.

METHODS

Systematic review with evidence searched from January 2002 to June 2010. Studies were included if they contained a measure of overweight and/or obesity between birth and 18 years (exposure measure) and premature mortality and physical morbidity (outcome) in adulthood.

RESULTS

Five eligible studies examined associations between overweight and/or obesity, and premature mortality: 4/5 found significantly increased risk of premature mortality with child and adolescent overweight or obesity. All 11 studies with cardiometabolic morbidity as outcomes reported that overweight and obesity were associated with significantly increased risk of later cardiometabolic morbidity (diabetes, hypertension, ischaemic heart disease, and stroke) in adult life, with hazard ratios ranging from 1.1-5.1. Nine studies examined associations of child or adolescent overweight and obesity with other adult morbidity: studies of cancer morbidity were inconsistent; child and adolescent overweight and obesity were associated with significantly increased risk of later disability pension, asthma, and polycystic ovary syndrome symptoms.

CONCLUSIONS

A relatively large and fairly consistent body of evidence now demonstrates that overweight and obesity in childhood and adolescence have adverse consequences on premature mortality and physical morbidity in adulthood.

Obesity and angiolymphatic invasion in primary breast cancer

BACKGROUND

Obesity is associated with poorer breast cancer-specific survival. The purpose of this study was to investigate the relationships between obesity and the presence of angiolymphatic invasion as well as other features of invasive breast cancer, including stage at presentation, estrogen receptor (ER) status, triple-negative phenotype, and tumor grade.

METHODS

Detailed clinical and pathologic data were abstracted from the medical records of all 1,312 patients with stage I-III primary breast cancer who had breast surgery at the University of Michigan Comprehensive Cancer Center between January 1, 2000 and December 31, 2006. Bivariate and multivariate analyses were conducted to investigate the relationships between body mass index and tumor biologic features, controlling for menopausal status, diabetes and hypertension, hormone replacement therapy before diagnosis, race, and ethnicity.

RESULTS

In multivariate analyses, severe obesity was independently associated with the presence of angiolymphatic invasion [odds ratio (OR) 1.80, 95% confidence interval (CI) 1.08-2.99, joint test of significance, P = 0.03]. Severe obesity was associated with lower likelihood of triple-negative breast cancer (OR 0.39, 95% CI 0.16-0.96). Among premenopausal women with diabetes, ER-negative (OR 5.22, 95% CI 1.12-24.29) and triple-negative (OR 14.8, 95% CI 1.92-113.91) disease was significantly more common.

DISCUSSION

In this large sample of invasive breast cancers, obesity was independently associated with the presence of angiolymphatic invasion. Higher rates of angiolymphatic invasion among obese women may account in part for poorer outcomes among obese women with breast cancer.

Lifestyle factors and colorectal cancer risk (1): systematic review and meta-analysis of associations with body mass index

OBJECTIVE

Excess body weight, defined by body mass index (BMI), may increase the risk of colorectal cancer. As a prerequisite to the determination of lifestyle attributable risks, we undertook a systematic review and meta-analysis of prospective observational studies to quantify colorectal cancer risk associated with increased BMI and explore for differences by gender, sub-site and study characteristics.

METHOD

We searched MEDLINE and EMBASE (to December 2007), and other sources, selecting reports based on strict inclusion criteria. Random-effects meta-analyses and meta-regressions of study-specific incremental estimates were performed to determine the risk ratio (RR) and 95% confidence intervals (CIs) associated with a 5 kg/m(2) increase in BMI.

RESULTS

We analysed 29 datasets from 28 articles, including 67,361 incident cases. Higher BMI was associated with colon (RR 1.24, 95% CIs: 1.20-1.28) and rectal (1.09, 1.05-1.14) cancers in men, and with colon cancer (1.09, 1.04-1.12) in women. Associations were stronger in men than in women for colon (P < 0.001) and rectal (P = 0.005) cancers. Associations were generally consistent across geographic populations. Study characteristics and adjustments accounted for only moderate variations of associations.

CONCLUSION

Increasing BMI is associated with a modest increased risk of developing colon and rectal cancers, but this modest risk may translate to large attributable proportions in high-prevalence obese populations. Inter-gender differences point to potentially important mechanistic differences, which merit further research.

Energy intake, physical activity, energy balance, and cancer: epidemiologic evidence

Energy intake, physical activity, and obesity are modifiable lifestyle factors. This chapter reviews and summarizes the epidemiologic evidence on the relation of energy intake, physical activity, and obesity to cancer. High energy intake may increase the risk of cancers of colon-rectum, prostate (especially advanced prostate cancer), and breast. However, because physical activity, body size, and metabolic efficiency are highly related to total energy intake and expenditure, it is difficult to assess the independent effect of energy intake on cancer risk. There are sufficient evidences to support a role of physical activity in preventing cancers of the colon and breast, whereas the association is stronger in men than in women for colon cancer and in postmenopausal than in premenopausal women for breast cancer. The evidence also suggests that physical activity likely reduces the risk of cancers of endometrium, lung, and prostate (to a lesser extent). On the other hand, there is little or no evidence that the risk of rectal cancer is related to physical activity, whereas the results have been inconsistent regarding the association between physical activity and the risks of cancers of pancreas, ovary and kidney. Epidemiologic studies provide sufficient evidence that obesity is a risk factor for both cancer incidence and mortality. The evidence supports strong links of obesity with the risk of cancers of the colon, rectum, breast (in postmenopausal women), endometrium, kidney (renal cell), and adenocarcinoma of the esophagus. Epidemiologic evidence also indicates that obesity is probably related to cancers of the pancreas, liver, and gallbladder, and aggressive prostate cancer, while it seems that obesity is not associated with lung cancer. The role of obesity in other cancer risks is unclear.

Body mass index, waist to hip ratio and waist/height in adult Polish women in relation to their education, place of residence, smoking and alcohol consumption

Obesity is a complex, multifactorial disorder that develops from genotype and environmental interactions. The aim of this study is to describe the variability of body mass index (BMI), waist to hip ratio (WHR) and waist to height (W/Ht) in adult Polish women, and to determine relationships between these variables and factors such as education, place of residence, smoking and alcohol drinking. The tested group consisted of 10,254 women aged 25-95 years, who voluntarily filled in questionnaires and participated in anthropometric measurements (body height and mass, waist and hip circumferences). The BMI, WHR and W/Ht values were calculated based on these measurements. The participants were differentiated in terms of education, residence and lifestyle (smoking, alcohol drinking). Chi-squared test, product-moment correlations, ANOVA, multiple correspondence analysis (MCA) and logistic regression with backward elimination were used to evaluate associations between social and lifestyle factors and BMI, WHR and W/Ht. The results confirm (1) the relationship between low social status and the risk of overweight and obesity as observed in developed countries; (2) higher susceptibility to environmental factors such as education, place of residence, smoking and alcohol drinking in younger (premenopausal) women; (3) the usefulness of simple and practical anthropometric indicators such as WHR and W/Ht for the identification of the higher risk of future metabolic diseases in obese people and those with a normal body mass.

Prospective cohort study of body mass index in adolescence and death from stomach cancer in Japan

We investigated the association between body mass index (BMI) values and the risk of death from stomach cancer later in life. From 1992 to 2000, 28 443 participants (13 211 men and 15 232 women) were followed, and 129 deaths from stomach cancer (86 men and 43 women) occurred. BMI (BMI at the baseline) and BMI(20y) (BMI at age 20 years) were obtained by questionnaire at the beginning of the study. Men in the middle and highest tertiles of BMI(20y) had a higher risk of death from stomach cancer than those in the lowest tertile (after controlling for covariates, hazard ratio [HR] = 2.73 with 95% confidence interval [CI] 1.26-5.89 for the middle tertile; HR = 2.15 with 95% CI 0.97-4.73 for the highest tertile), although there was no significant trend (P = 0.30). Likewise, women in the middle and highest tertiles of BMI(20y) had an increased risk of death from stomach cancer (HR = 5.17 with 95% CI 1.50-17.87 for the middle tertile; HR = 4.22 with 95% CI 1.18-15.05 for the highest tertile; P for trend = 0.05). The analysis of BMI at the baseline did not show a significant relationship with the risk of death from stomach cancer. These results suggest that a high BMI(20y) is associated with an increased risk of death from stomach cancer.

Obesity, metabolic syndrome, and prostate cancer

Although obesity has been consistently linked to an increased risk of several malignancies, including cancers of the colon, gallbladder, kidney, and pancreas, its role in prostate cancer etiology remains elusive. Data on the association between obesity and prostate cancer incidence are inconsistent, and in some studies obesity is associated with an increase in risk of high-grade prostate cancer but with a decrease in risk of low-grade tumors. In contrast, obesity has been consistently associated with an increased risk of prostate cancer aggressiveness and mortality. The differential effects of obesity on subtypes of prostate cancer suggest etiologic heterogeneity in these tumors and complex interactions between androgen metabolism and several putative risk factors, including insulin resistance, diabetes, inflammation, and genetic susceptibility, on prostate cancer risk. Data on the role of abdominal obesity, insulin resistance, and metabolic syndrome in prostate cancer etiology are limited. Obesity has been shown to be associated with a state of low-grade chronic inflammation, and insulin resistance and the metabolic syndrome are associated with adverse metabolic profiles and with higher circulating concentrations of inflammation-related markers, including leptin, interleukin-6, and tumor necrosis factor-, many of which have been shown to enhance tumor growth. Thus, whether obesity and metabolic syndrome modulate the risk of prostate cancer through chronic inflammation needs to be investigated further. Given that the prevalence of obesity and metabolic syndrome is increasing worldwide and that the world population is aging, the roles of obesity and metabolic syndrome in prostate carcinogenesis warrant further clarification.

The prevention of prostate cancer

From our better understanding of the natural history of prostate cancer, it is not unreasonable to believe that the disease is preventable. Prostate cancer has become a major healthcare problem worldwide, as life expectancy increases. Moreover, the cancer is slow growing, with a period of about 20-25 years from initiation to the stage when the clinically detectable phenotype can be identified. This review provides a simple overview of the endocrinology of prostate cancer and discusses some of the pharmaceutical agents that have been or are being tested to restrain, possibly arrest, the progression of this slowly growing cancer. Also discussed are many of the dietary factors that may influence the molecular or endocrine events implicated in its development. Dietary factors are considered responsible for the geographical differences in prostate cancer incidence and mortality. Since about 50% of all men worldwide, from both East and West, show evidence of microscopic cancer by 50 years of age, growth restraint would appear to be the pragmatic option to the possibility of preventing initiation.

Obesity and prostate cancer: epidemiology and clinical implications

OBJECTIVES

Both obesity and prostate cancer (PCa) are epidemic in Western society. Although initial epidemiological data appeared conflicting, recent studies have clarified the association between obesity and PCa. Therefore, we sought to review the epidemiological data linking obesity and PCa with an emphasis on the clinical implications and how to improve outcomes among obese men.

METHODS

A PubMed search using the keywords "prostate cancer" and "obesity" was performed. Relevant articles and references were reviewed for data on the association between obesity and PCa.

RESULTS

Recent data suggest obesity is associated with reduced risk of nonaggressive disease but increased risk of aggressive disease. This observation may be explained in part by an inherent bias in our ability to detect PCa in obese men (lower PSA values and larger sized prostates, making biopsy less accurate for finding an existent cancer), which ultimately leads to increased risk of cancer recurrence after primary therapy and increased PCa mortality. Despite this detection bias potentially contributing to more aggressive cancers, multiple biological links also exist between obesity and PCa including higher estradiol, insulin, free IGF-1, and leptin levels, and lower free testosterone and adiponectin levels, all of which may promote more aggressive cancers.

CONCLUSIONS

The association between obesity and PCa is complex. Emerging data suggest obesity increases the risk of aggressive cancer, while simultaneously decreasing the risk of more indolent disease. This is likely driven by both "biological" and "nonbiological" causes. Simple changes in clinical practice patterns can reduce the impact of nonbiological causes and may help improve PCa outcomes among obese men.

Body size and composition and prostate cancer risk: systematic review and meta-regression analysis

The evidence that measures of obesity and stature are associated with prostate cancer is weak and inconsistent. We performed a systematic review and meta-analysis of the relationship between body mass index (BMI), height, weight, waist circumference and waist-to-hips ratio (WHR) and the risk of prostate cancer. Study-specific dose-response slopes were obtained, and random effects rate ratios (RRs) were computed from linear meta-regression models. We included 55,521 cases identified among 2,818,767 men from 31 cohort studies, and 13,232 cases and 16,317 controls from 25 case-control studies. The overall RR for BMI was 1.05 per 5 kg/m2 increment, 95% CI 1.01-1.08. For studies that reported results by stage of disease, the RRs were stronger for advanced disease (RR 1.12 per 5 kg/m2 increment, 95% CI 1.01-1.23) compared with localized disease (RR 0.96 per 5 kg/m2 increment, 95% CI 0.89-1.03), p = 0.02. Height was also positively associated with risk (RR 1.05 per 10 cm increment, 95% CI 1.02-1.09), but the evidence was weak for weight (RR 1.01 per 10 kg increment, 95% CI 0.97-1.04), waist circumference (RR 1.03 per 10 cm increment, 95% CI 0.99-1.07), and WHR (RR 1.11 per 0.1 unit increment, 95% CI 0.95-1.30). Stronger associations were observed among cohort studies compared with case-control studies for BMI (p = 0.006), height (p < 0.001) and weight (p = 0.02). This meta-analysis indicates that obesity is weakly associated with an increased risk of prostate cancer (particularly advanced stage tumors). While increased stature may also increase risk, there is little evidence for an association with central obesity.

Riesgo oncológico de la obesidad

This article presents an update of scientific evidence about the relation of obesity with the incidence or mortality by cancer. Almost all large epidemiological studies agree about the oncological risk of obesity, especially with regard to some types of cancers. Different physiopathological theories to explain this association have been proposed, from simple mechanical or dietetical causes to genetic or immunologic factors, including a possible role of hormones or adipocyte humoral factors. Moreover, obesity can play a role in the prognosis of certain cancers. Prevention of obesity must be included among the strategies to fight cancer.

Survival in colorectal cancer: impact of body mass and exercise

Is there a relationship between exercise and body composition prior to a diagnosis of colorectal cancer and survival afterwards?

Effects of obesity on growth and puberty

Nutrition is an important regulator of the tempo of human growth. Infancy may represent a critical "window" where variations in nutrition have longer-term consequences for growth and development. Rapid weight gain during infancy is associated with accelerated growth and early pubertal development. Rapid weight gain in infancy is also associated with the development of insulin resistance and an exaggerated adrenarche. Such circulating hormonal changes, together with elevated leptin levels and integral effects of fat cells on hormone action through local 11beta-steroid dehydrogenase and aromatase activity could effect rate of progression of pubertal development in obese subjects. The secular trends in growth and maturation are partly attributed to changing nutrition. Recent data suggest that age at menarche may be static, but there is a debate as to whether the first signs of puberty are being seen much earlier in obese girls. Rapid early weight gain, obesity and early development may have implications for later health through the development of PCOS and overall association with cancer risk.

Obesity before age 30 years and risk of advanced prostate cancer

Adult obesity has shown little association with prostate cancer risk, but obesity at younger ages may be associated with reduced risk. In 1997-2000, the relation between obesity before age 30 years and incident advanced prostate cancer was investigated in a population-based case-control study of African-American and White men (568 cases, 544 controls) in California. Unconditional logistic regression was used to estimate odds ratios and 95% confidence intervals, adjusted for age, race, family history of prostate cancer, and saturated fat intake. Measures of obesity for age 10 years tended to be inversely associated with prostate cancer (odds ratio (OR) = 0.79, 95% confidence interval (CI): 0.46, 1.38 for selecting the "obese" pictogram and OR = 0.76, 95% CI: 0.52, 1.11 for reporting being heavier than peers). The decreased risk was more pronounced at ages 20-29 years (OR = 0.53, 95% CI: 0.28, 1.00 for the "obese" drawing, OR = 0.59, 95% CI: 0.40, 0.88 for being heavier than peers, and OR = 0.40, 95% CI: 0.20, 0.81 for body mass index > or =30 kg/m(2)). In addition, both "obese" and small waist size at ages 20-29 years showed inverse trends. This research implicating early-life body size in prostate cancer development helps to elucidate causal mechanisms, such as altered sex hormone profiles during critical developmental periods, potentially involved in development of the disease.

Childhood obesity and hormonal abnormalities associated with cancer risk

There is growing evidence that overweight and obesity increase the risk of certain cancers. Studies in adults support the role of insulin-like growth factors (IGFs) and oestrogens in the pathogeneses of several cancers. We propose that hormone alterations described as risk factors for cancer in obese adults are present in prepubertal obese children. A group of obese children aged 6-9 years (n=40), and control group paired for age and sex, were used for the study. The obese children presented a significantly high level of IGF-I (P=0.0173) and insulin (P=0.0250), with a drop in sex hormone-binding globulin (SHBG) (P=0.0282). The 17 beta-oestradiol (E2)/SHBG ratio increase in obese subjects was marginally significant (P=0.0635). Grouping together all the children in quartiles for insulin and body mass index, the upper quartiles showed a rise in IGF-I and E2/SHBG. In a multivariant correlation analysis, only height (partial r=0.2464) and insulin (partial r=0.3002) were independent prediction variables for IGF-I concentration. The only variables statistically correlated with the E2/SHBG ratio were insulin (r=0.2879) and IGF-I (r=0.4140). The obese children in our study showed hormone changes described as risk factors for cancer in obese adults. These changes were significantly associated with the hyperinsulinaemia. We hypothesize that this potential risk should be taken into account given the long period of exposure involved in the presence of hormone alterations at such early ages.

Adiponectin-induced antiangiogenesis and antitumor activity involve caspase-mediated endothelial cell apoptosis

Obesity is a risk factor for the development of many severe human diseases such as cardiovascular disorders, diabetes, and cancer, which are tightly linked to angiogenesis. The adipose tissue produces several growth factors/hormones including leptin, tumor necrosis factor alpha, and adiponectin. It has been found that adiponectin levels are reduced in obesity. Here, we report a unique function of adiponectin as a negative regulator of angiogenesis. In vitro, adiponectin potently inhibits endothelial cell proliferation and migration. In the chick chorioallantoic membrane and the mouse corneal angiogenesis assays, adiponectin remarkably prevents new blood vessel growth. Further, we demonstrate that the antiendothelial mechanisms involve activation of caspase-mediated endothelial cell apoptosis. Adiponectin induces a cascade activation of caspases-8, -9, and -3, which leads to cell death. In a mouse tumor model, adiponectin significantly inhibits primary tumor growth. Impaired tumor growth is associated with decreased neovascularization, leading to significantly increased tumor cell apoptosis. These data demonstrate induction of endothelial apoptosis as an unique mechanism of adiponectin-induced antiangiogenesis. Adiponectin, as a direct endogenous angiogenesis inhibitor, may have therapeutic implications in the treatment of angiogenesis-dependent diseases.

Fetal growth and adult diseases

Evidence that the quality of fetal growth and development has strong and, in widely varying populations, reproducible effects on susceptibility to many common adult human diseases has only been acquired relatively recently. The importance of this largely environmentally determined process in relation to genetic factors remains a topic of great debate. Diseases that have been implicated include cardiovascular disease, hypertension, osteoporosis, schizophrenia, depression, breast cancer, and the polycystic ovary syndrome. This short review focuses on fetal programming of appetite and obesity, coronary artery disease and hypertension, type-2 diabetes, and cancer. The enormous importance of establishing the precise role of environmentally determined poor fetal growth in causing susceptibility to adult disease, usually in combination with adult obesity, (which may itself be a consequence of the same process) is emphasized. Once this is clear, there will be a major opportunity for disease prevention.

Examining the relationship between obesity and prostate cancer

Affecting over 30% of the population, obesity is an epidemic in the United States and is associated with multiple chronic medical problems. Obesity is also associated with numerous hormonal changes, many of which have been implicated in prostate cancer development and progression. Although, on the whole, controversy exists over whether obesity increases the risk of prostate cancer, data strongly suggest that obesity is a significant risk factor for prostate cancer death. In this review, we discuss the epidemiologic data surrounding obesity and prostate cancer. We also discuss some of the sequelae of obesity and their relationships with prostate cancer, including alterations in insulin, the insulin-like growth factor axis, and leptin levels; insulin resistance; and diabetes. Although a complete overview of all the various dietary and lifestyle factors that are associated with obesity and prostate cancer risk is beyond the scope of this review, we discuss data concerning the relationship between a high-fat diet and prostate cancer.

Childhood body mass index and later cancer risk: A 50-year follow-up of the Boyd Orr study

Associations between childhood BMI and adult cancer risk were investigated in a historical cohort study based on the Carnegie ("Boyd Orr") Survey of Diet and Health in Pre-War Britain (1937-9). In 14 centres in England and Scotland, children had their height and weight measured. We included 2,347 individuals aged between 2 and 14 years 9 months at the time of measurement, who were traced through the National Health Service Central Register. Relative cancer risk (registration or death) was estimated in relation to age- and sex-specific BMI SD scores. We studied associations with (i) all cancers, (ii) cancer groups stratified according to their relationship to smoking and (iii) certain site-specific cancers. In the 50 years of follow-up, 188 men and 192 women developed cancer. There was a 9% increase (95% CI -3 to 22%) in risk of cancer in adulthood per SD increase in BMI measured in childhood. There was no evidence of confounding by childhood or adulthood socioeconomic position, other anthropometric variables, childhood energy intake or birth order. There was a 30% increase (95% CI 10-54%) in risk of smoking-related cancers per SD increase in childhood BMI. There was no relationship between BMI and cancers not related to smoking. Associations for all cancers and non-smoking-related cancers tended to be stronger in children who were measured at an older (>8 years) rather than a younger (< or =8 years) age. We conclude that childhood BMI is related to increased risk of cancer in later life, particularly smoking-related cancers.

Association between course of study at university and cause-specific mortality

Although socioeconomic position is clearly related to mortality and one measure of this is length of education, it is not known whether the choice of course at university determines future health. We therefore investigated the association between faculty of study and all-cause and cause-specific mortality in a prospective follow-up of male students who underwent health examinations while attending Glasgow University from 1948 to 1968. Among the 9887 (84%) alumni traced by means of the NHS Central Register, 8367 (85%) had full data on important potential confounding variables; 939 of these men had died. Physiological variables differed little between students from the various faculties. Medical students were most likely to come from affluent social backgrounds and, after law students, were most likely to be smokers. Compared with former medical students, former arts and law students had excess all-cause and cardiovascular disease mortality, while science and engineering alumni had similar risks. Former medical students had lower lung cancer mortality than other alumni but higher mortality from alcohol-related causes including accidents, suicide and violence. The lower mortality risks observed among former medical and engineering students may be due to their better employment prospects and healthier lifestyle behaviours, although the high mortality from alcohol-related causes among former medical students underscores the complexity of choice of health behaviour. The findings point to the potential for disease prevention among the large proportion of the population who now have third-level education.

Association between Course of Study at University and Cause-Specific Mortality

Although socioeconomic position is clearly related to mortality and one measure of this is length of education, it is not known whether the choice of course at university determines future health. We therefore investigated the association between faculty of study and all-cause and cause-specific mortality in a prospective follow-up of male students who underwent health examinations while attending Glasgow University from 1948 to 1968.

Among the 9887 (84%) alumni traced by means of the NHS Central Register, 8367 (85%) had full data on important potential confounding variables; 939 of these men had died. Physiological variables differed little between students from the various faculties. Medical students were most likely to come from affluent social backgrounds and, after law students, were most likely to be smokers. Compared with former medical students, former arts and law students had excess all-cause and cardiovascular disease mortality, while science and engineering alumni had similar risks. Former medical students had lower lung cancer mortality than other alumni but higher mortality from alcohol-related causes including accidents, suicide and violence.

The lower mortality risks observed among former medical and engineering students may be due to their better employment prospects and healthier lifestyle behaviours, although the high mortality from alcohol-related causes among former medical students underscores the complexity of choice of health behaviour. The findings point to the potential for disease prevention among the large proportion of the population who now have third-level education.