A prospective Swedish study on body size, body composition, diabetes, and prostate cancer risk

Obesity may be associated with increased risk of prostate cancer (PCa). According to one hypothesis, obesity could lower the risk of non-aggressive tumours, while simultaneously increasing the risk of aggressive cancer. Furthermore, central adiposity may be independently associated with PCa risk; it is also associated with diabetes, which itself may influence risk of PCa. We studied the associations between height, body composition, and fat distribution, diabetes prevalence and risk of total, aggressive, and non-aggressive PCa in 10 564 initially cancer-free men (aged 45–73 years) of the population-based Malmö Diet and Cancer cohort. Anthropometric and body composition measurements, including bioelectrical impedance for estimation of fat mass, were performed by study nurses. Diabetes prevalence was self-reported. Cancer cases and clinical characteristics were ascertained through national and regional registry data. Dietary and other background data were obtained through a modified diet history method and an extensive questionnaire. During a mean follow-up of 11.0 years, 817 incidental PCa cases were diagnosed. Of these, 281 were classified as aggressive. There were 202 cases occurring before 65 years of age. Height was positively associated with total and non-aggressive PCa risk. Waist–hip ratio (WHR), a measure of central adiposity, was positively associated with PCa before age 65, and less strongly, with total PCa. This association was independent of body mass index (BMI) and other potential confounders. General adiposity, expressed as BMI or body fat percentage, and prevalent diabetes were not associated with PCa risk. In this study, WHR and body height were stronger PCa predictors than general adiposity.     

Obesity and prostate cancer mortality

It has long been known that obesity modestly increases the risk of prostate cancer mortality. Only recently, however, have studies examined whether this association is due to an increased risk of aggressive disease and/or worse outcomes following initial diagnosis and treatment. This distinction is important, because if obesity increases the risk of metastasis and death following treatment, weight loss could be an effective adjunct treatment. We now have good evidence that obesity increases the risk of aggressive prostate cancer, but reduces the risk of low-grade, nonaggressive cancer. In addition, several studies have found that obesity increases the risk of biochemical recurrence following prostatectomy; however, the few studies that have examined more definitive end points, metastases and death, have been less consistent. Furthermore, there are no studies that have examined whether weight loss after diagnosis favorably affects prostate cancer outcome. While accepting the current limitations in our knowledge base, it is our opinion that it is appropriate for physicians to counsel their patients to lose weight following prostate cancer diagnosis and motivate this change in behavior by emphasising the likely benefit of improving long-term outcome.     

Obesity, adipokines, and prostate cancer (review)

Prostate cancer, the third most common cancer in men worldwide, varies substantially according to geographic region and race/ethnicity. Obesity and associated endocrine variation are foremost among the risk factors that may underlie these regional and ethnic differences. The association between obesity and prostate cancer incidence is complex and has yielded inconsistent results. Studies that have linked obesity with prostate cancer mortality, advanced stage disease, and higher grade Gleason score, however, have produced more consistent findings, indicating that obesity may not necessarily increase the risk of prostate cancer, but may promote it once established. Additionally, metabolic syndrome, which includes disturbed glucose metabolism and insulin bioactivity, may also be associated with prostate carcinogenesis. Adipokines, defined as biologically active polypeptides produced by adipose tissue, have been linked with a number of carcinogenic mechanisms, including angiogenesis, cell proliferation, metastasis, and alterations in sex-steroid hormone levels. A number of emerging studies have implicated the role of adipokines in prostate carcinogenesis. This review explores the specific roles of several adipokines as putative mediating factors between obesity and prostate cancer with particular attention to leptin, interleukin-6 (IL-6), heparin-binding epidermal growth factor-like growth factor (HB-EGF), vascular endothelial growth factor (VEGF) and adiponectin.     

Changes in body composition during hormonal therapy for prostate cancer

Androgens are important determinants of body composition in men. Androgen-deprivation therapy, the mainstay of treatment for advanced prostate cancer, increases fat mass and decreases lean body mass. These adverse changes in body composition may contribute to treatment-related fatigue, fracture risk, insulin resistance, and increased cardiovascular disease risk. Potential strategies to treat or prevent these adverse body composition changes include exercise training, alternative forms of hormonal therapy, and insulin-sensitizing agents.     

Phytoestrogens,body composition,and breast cancer

To the extent that diet is involved in the etiology of breast cancer, its effect may be mediated, in part, through hormonal mechanisms. It has been suggested that the consumption of phytoestrogens is related inversely to breast cancer risk. Phytoestrogens are weak estrogens of plant derivation that may have antiestrogenic effects through competitively binding to estrogen receptors, thus diminishing the binding of stronger endogenous estrogens. This paper advances the hypothesis that, through this mechanism, dietary phytoestrogens may attenuate the adverse consequences of obesity on the development of postmenopausal breast cancer. Such an association might partly explain the low breast cancer rates observed among postmenopausal Hispanic women despite their greater adiposity, an important breast cancer risk factor. This hypothesis would lead us to expect that obesity increases the risk of postmenopausal breast cancer in women consuming small quantities of phytoestrogens but does not increase risk in women consuming larger quantities. If the hypothesis is confirmed, such an association could have important implications for reducing breast cancer risk through diet, using naturally occurring substances, particularly in women for whom postmenopausal obesity is an important health concern.This research was supported in part by a grant from the Fashion Times II committee in support of breast cancer research.     

Obesity, diabetes, and risk of prostate cancer: results from the prostate cancer prevention trial.

Studies on the relationship between obesity and prostate cancer incidence are inconsistent. In part, this inconsistency may be due to a differential effect of obesity on low-grade and high-grade cancer or confounding of the association of obesity with prostate cancer risk by diabetes. We investigated the associations of obesity and diabetes with low-grade and high-grade prostate cancer risk. Data were from 10,258 participants (1,936 prostate cancers) in the Prostate Cancer Prevention Trial who all had cancer presence or absence determined by prostate biopsy. Multiple logistic regression was used to model the risk of total prostate cancer, and polytomous logistic regression was used to model the risk of low-grade and high-grade prostate cancer. Compared with men with body mass index < 25, obese men (body mass index > or =30) had an 18% [odds ratio (OR), 0.82; 95% confidence interval (95% CI), 0.69-0.98] decreased risk of low-grade prostate cancer (Gleason <7) and a 29% (OR, 1.29; 95% CI, 1.01-1.67) increased risk of high-grade prostate cancer (Gleason > or =7) or, alternatively, a 78% (OR, 1.78; 95% CI, 1.10-2.87) increased risk defining high-grade cancer as Gleason sum 8 to 10. Diabetes was associated with a 47% (OR, 0.53; 95% CI, 0.34-0.83) reduced risk of low-grade prostate cancer and a 28% (OR, 0.72; 95% CI, 0.55-0.94) reduced risk of high-grade prostate cancer. Associations of obesity or diabetes with cancer risk were not substantially changed by mutually statistical controlling for each other. Obesity increases the risk of high-grade but decreases the risk of low-grade prostate cancer, and this relationship is independent of the lower risk for prostate cancer among men with diabetes.     

Osteoporosis and other adverse body composition changes during androgen deprivation therapy for prostate cancer

Osteoporosis and other body composition changes are important complications of androgen deprivation therapy (ADT) for prostate cancer. Bilateral orchiectomy and gonadotropin-releasing hormone agonist treatment decrease bone mineral density and increase fracture risk. Other factors including diet and lifestyle may contribute to bone loss in men with prostate cancer. Estrogens play an important role in male bone metabolism. Androgen deprivation therapy with estrogens probably causes less bone loss than bilateral orchiectomy or gonadotropin-releasing hormone agonist treatment. Bicalutamide monotherapy increases serum estrogen levels and may also spare bone. Lifestyle modification including smoking cessation, moderation of alcohol use, and regular weight bearing exercise are recommended to decrease treatment-related bone loss. Supplemental calcium and vitamin D are also recommended. Pamidronate (Aredia®), an intravenous bisphosphonate, prevents bone loss during ADT. Other bisphosphonates are probably effective but have not been studied in hypogonadal men. Androgen deprivation therapy increases fat mass and decreases muscle mass. These body composition changes may contribute to treatment-related decreases in physical capacity and quality of life.     

Obesity, adipokines, and prostate cancer in a prospective population-based study.

BACKGROUND: The purpose of this investigation was to examine the association of obesity and the adipokines leptin, adiponectin, and interleukin-6 (IL-6) with prostate cancer risk and aggressiveness. METHODS: One hundred twenty-five incident prostate cancer cases and 125 age-matched controls were sampled from among participants in the original San Antonio Center for Biomarkers of Risk of Prostate Cancer cohort study. The odds ratios (OR) of prostate cancer and high-grade disease (Gleason sum >7) associated with the WHO categories of body mass index (kg/m(2)) and with tertiles of serum concentrations of adiponectin, leptin, and IL-6 were estimated using multivariable conditional logistic regression models. RESULTS: Body mass index was not associated with either incident prostate cancer [obese versus normal; OR, 0.75; 95% confidence interval (95% CI), 0.38-1.48; P(trend) = 0.27] or high-grade versus low-grade disease (OR, 1.17; 95% CI, 0.39-3.52; P(trend) = 0.62). Moreover, none of the three adipokines was statistically significant associated with prostate cancer risk or high-grade disease, respectively: leptin (highest versus lowest tertile; OR, 0.77; 95% CI, 0.28-1.37; P(trend) = 0.57; OR, 1.20; 95% CI, 0.48-3.01; P(trend) = 0.85); adiponectin (OR, 0.87; 95% CI, 0.46-1.65; P(trend) = 0.24; OR, 1.93; 95% CI, 0.74-5.10; P(trend) = 0.85); IL-6 (OR, 0.84; 95% CI, 0.46-1.53; P(trend) = 0.98; OR, 0.84; 95% CI, 0.30-2.33; P(trend) = 0.17). CONCLUSIONS: Findings from this nested case-control study of men routinely screened for prostate cancer and who had a high prevalence of overweight and obesity do not provide evidence to support that prediagnostic obesity or factors elaborated by fat cells strongly influence prostate cancer risk or aggressiveness. However, due to the small sample population, a small or modest effect of obesity and adipokines on these outcomes cannot be excluded.     

Obesity, body fat distribution, and sex hormones in breast cancer patients

This study addresses the relationship between female sex hormones, obesity, body fat distribution, and breast cancer. Increasing obesity correlated with a progressive fall in sex hormone-binding globulin (SHBG) level and an increase in testosterone level. Premenopausal breast cancer patients were found to have significantly lower levels of SHBG compared with age-matched and weight-matched controls. This difference in SHBG level was not noted in postmenopausal breast cancer patients. The SHBG level decreased with increasing upper body fat localization in breast cancer patients and controls. This effect was more marked in breast cancer patients which may explain our earlier finding that women with upper body fat localization are at increased risk for developing breast cancer.     

Early growth,adult body size and prostate cancer risk

The role of growth from birth through puberty and through adult life has been the subject of epidemiologic investigation in regard to the risk of prostate cancer but the evidence remains weak and inconsistent. We investigated associations between prostate cancer risk and a number of markers of body growth, size and changes to size in a population-based, case-control study in Australia from 1994 to 1998. We analyzed data obtained in face-to-face interviews from 1,476 cases and 1,409 controls. The main outcomes of interest were the timing of the growth spurt in adolescence, the experience of acne and interviewer observation of facial acne scarring, body size at age 21, body size in reference year, maximum body weight and rate of body size change since age 21 years. Analysis was performed on all cases and also by tumour grade. We found no associations with measures of body size including body mass index and lean body mass at age 21 or later in adult life. Having a growth spurt later than friends reduced risk (odds ratio [OR] 0.79 [0.63-0.97]) and some measures of acne also gave odds ratios less than 1, for example, having facial acne scarring gave an OR of 0.67 (0.45-1.00). We conclude that markers of delayed androgen action, such as delayed growth spurt in puberty, and markers of other androgen-dependent activity in puberty, such as facial acne scarring, are associated with prostate cancer risk but we could detect no associations with markers of adult body size and growth including lean body mass.     

Obesity and body fat distribution and breast cancer prognosis

This study addresses the effect of obesity and body fat distribution on axillary lymph node involvement, tumor size, and estrogen receptor (ER) level in breast cancer patients. Anthropometric measurements were prospectively obtained on 248 consecutively and newly diagnosed women with invasive breast cancer. The anthropometric measurements evaluated were abdomen, thigh, subscapular, and midaxillary skinfolds; weight; and height. Weight and Quetelet Index (kg/m2) were significantly (P = 0.001) associated with lymph node involvement in postmenopausal patients. The abdomen:thigh skinfold ratio was significantly higher in premenopausal patients (P = 0.004) and postmenopausal (P = 0.03) without axillary node involvement compared with women with 4+ axillary node involvement. The abdomen:thigh skinfold was higher (P = 0.05) in women with smaller breast cancers (less than 2.0 cm) and higher ER levels. Weight and Quetelet Index did not affect tumor size or ER level. This study demonstrated that obese postmenopausal women who developed breast cancer tend to have more axillary node involvement than their leaner counterparts. Generalized obesity did not affect tumor size or ER level. Premenopausal and postmenopausal women with upper body fat distribution appear to be a subset of women who have a more favorable prognosis as measured by less lymph node involvement, smaller tumors, and higher levels of ER in their tumors.     

Physical activity,body size and composition,and risk of ovarian cancer

Objectives  

We examined the association between risk of ovarian cancer and physical activity and anthropometry (body mass index, height, waist, fat, and fat-free mass) in the Melbourne Collaborative Cohort Study.     

Body size and composition and prostate cancer risk.

Reported associations between body measurements and the risk of prostate cancer are weak and inconsistent, possibly because some measures used do not differentiate between adipose and nonadipose tissue, body components that would theoretically have different associations with prostate cancer. Some studies have addressed this problem by estimating lean body mass from subjects' age, height, and weight. In a prospective cohort study of men 27-75 years of age at recruitment in 1990-1994, body measurements were taken by trained interviewers. Nonadipose and adipose mass were calculated from bioelectric impedance analysis. Incident prostate cancers were ascertained by use of the population cancer registry. Altogether 16,336 men contributed 113,535 person-years and 477 cancers, of which 79 were "aggressive," to the analysis. We found no overall association between prostate cancer and any anthropometric measurement. Analysis stratified by cancer aggressiveness revealed modest associations between measures of adiposity and the risk of aggressive disease. On the basis of the WHO cut points and compared with men in the normal range of body mass index, the risk ratio for obese men was 2.2 (95% confidence interval, 1.2-4.1). For each 10-kg increase in fat mass, the risk ratio was 1.4 (95% confidence interval, 1.0-1.8). Energy imbalance may play a role in the development of aggressive prostate cancer.     

Obesity and the risk of prostate cancer (United States)

The role of obesity in prostate cancer etiology remains controversial. A recent report suggested that obese men younger than age 60 may have a lower risk of developing prostate cancer than men the same age who are not obese. The current study used a nested, matched case–control study design and data collected in the General Practice Research Database between January 1991 and December 2001 to assess the association between body mass index (BMI) and the risk of incident prostate cancer. Seven hundred and thirty cases of prostate cancer with adequate information on BMI were identified and matched to 2740 controls on age, sex, general practice, and index date. Obese men (BMI ≥ 30.0 kilograms [kg]/square of height in meters [m²]) were at lower risk of developing prostate cancer (AOR=0.78, 95% CI: 0.56, 1.09) compared to normal weight men (BMI=23.0–24.9 kg/m²), and the data best fit an inverse quadratic model for the relation between BMI and the risk of prostate cancer. This study provides modest support for a protective association between obesity and the risk of incident prostate cancer.     

Stereotactic body radiation therapy for prostate cancer

Stereotactic body radiation therapy (SBRT) is a promising treatment option for prostate cancer. Hypofractionation regimens, such as SBRT, may be more advantageous compared with conventional regimens because low α:β ratio of prostate cancer has high sensitivity to dose per fraction. In addition, a smaller and tighter margin with SBRT is expected to provide a low toxicity rate without reducing tumor control. The purpose of this article is to examine radiobiological, technical and clinical aspects of SBRT for prostate cancer.