A Case-Control Study on Fat-to-Muscle Ratio and Risk of Breast Cancer

Association of fat-to-muscle mass ratio with physical activity and dietary protein, carbohydrate, sodium, and fiber intake in a cross-sectional study

Higher fat-to-muscle mass ratio (FMR) is reported to be a risk factor for various diseases, including type 2 diabetes and cardiovascular diseases, and mortality. Although this association suggests that reducing FMR may help to prevent certain diseases and mortality, the relationship between FMR and lifestyle factors is unclear. Therefore, we performed a cross-sectional study with the aim to elucidate this relationship. This cross-sectional study included 1518 healthy Japanese adults aged 30 to 64 years. We measured FMR in the whole body, arms, legs, and trunk and assessed various lifestyle factors. Then, we performed forced entry multiple regression analyses for FMR with the following variables: sex, age, physical activity, dietary intake, sleep quality, cigarette smoking, stress levels, and body mass index. As a result, whole-body and regional FMRs were correlated with female sex (β = 0.71); age (β = 0.06); physical activity (β = - 0.07); dietary intake of protein (β = - 0.12), carbohydrate (β = 0.04), sodium (β = 0.13), and fiber (β = - 0.16); and body mass index (β = 0.70). The results suggest that in the Japanese middle-aged population, low FMR is associated with certain lifestyle factors, i.e. higher physical activity and a diet with higher protein and fiber and lower carbohydrate and sodium, independent of age, sex, and body mass index.

Body Mass Index Is Inversely Associated with Risk of Postmenopausal Interval Breast Cancer: Results from the Women's Health Initiative

Interval breast cancer refers to cancer diagnosed after a negative screening mammogram and before the next scheduled screening mammogram. Interval breast cancer has worse prognosis than screening-detected cancer. Body mass index (BMI) influences the accuracy of mammography and overall postmenopausal breast cancer risk, yet how is obesity associated with postmenopausal interval breast cancer incidence is unclear. The current study included cancer-free postmenopausal women aged 50-79 years at enrollment in the Women's Health Initiative who were diagnosed with breast cancer during follow-up. Analyses include 324 interval breast cancer cases diagnosed within one year after the participant's last negative screening mammogram and 1969 screening-detected breast cancer patients. Obesity (BMI ≥ 30 kg/m2) was measured at baseline. Associations between obesity and incidence of interval cancer were determined by sequential logistic regression analyses. In multivariable-adjusted models, obesity was inversely associated with interval breast cancer risk [OR (95% CI) = 0.65 (0.46, 0.92)]. The inverse association persisted after excluding women diagnosed within 2 years [OR (95% CI) = 0.60 (0.42, 0.87)] or 4 years [OR (95% CI) = 0.56 (0.37, 0.86)] of enrollment, suggesting consistency of the association regardless of screening practices prior to trial entry. These findings warrant confirmation in studies with body composition measures.

Cancer Risk in Normal Weight Individuals with Metabolic Obesity: A Narrative Review

Obesity represents one of the most significant public health challenges worldwide. Current clinical practice relies on body mass index (BMI) to define the obesity status of an individual, even though the index has long been recognized for its limitations as a measure of body fat. In normal BMI individuals, increased central adiposity has been associated with worse health outcomes, including increased risks of cardiovascular disease and metabolic disorders. The condition leading to these outcomes has been described as metabolic obesity in the normal weight (MONW). More recent evidence suggests that MONW is associated with increased risk of several obesity-related malignancies, including postmenopausal breast, endometrial, colorectal, and liver cancers. In MONW patients, the false reassurance of a normal range BMI can lead to lost opportunities for implementing preventive interventions that may benefit a substantial number of people. A growing body of literature has documented the increased risk profile of MONW individuals and demonstrated practical uses for body composition and biochemical analyses to identify this at-risk population. In this review, we survey the current literature on MONW and cancer, summarize pathophysiology and oncogenic mechanisms, highlight potential strategies for diagnosis and treatment, and suggest directions for future research.

The association between DXA-derived body fat measures and breast cancer risk among postmenopausal women in the Women's Health Initiative

Background

Most studies demonstrating an association between excess adiposity and postmenopausal breast cancer have used anthropometric measures, particularly body mass index (BMI). However, more direct body fat measures may more accurately determine the relationship between body fat distribution and breast cancer risk.

Methods

Cox proportional hazards regression models were created to examine the associations of dual‐energy x‐ray absorptiometry (DXA) body fat measures (at baseline and during follow‐up) with breast cancer risk among 10 931 postmenopausal women from the Women's Health Initiative cohort. A total of 639 incident invasive breast cancer cases (including 484 estrogen receptor positive (ER+) cases) were ascertained after a median follow‐up of 15.0 years.

Results

Excess whole body fat mass and trunk fat mass were positively associated with risk invasive breast cancer risk. These associations persisted even after additional adjustment for standard anthropometric measures. In time‐dependent analyses, we observed that both whole body fat mass and trunk fat mass, in the highest versus lowest category, were associated with a doubling of risk of invasive breast cancer overall (HR: 2.17; 95% CI: 1.54‐3.05 and 2.20; 1.55‐3.14, respectively) and of ER+ breast cancer (2.05; 1.37‐3.05 and 2.03; 1.34‐3.07, respectively). The remaining DXA measures were also positively associated with breast cancer risk in baseline and time‐dependent analyses.

Conclusion

These findings suggest that DXA‐derived body fat measures are positively associated with breast cancer risk after adjustment for BMI and other conventional breast cancer risk factors.

The association between fat mass and the risk of breast cancer: A systematic review and meta-analysis

BACKGROUND & AIMS

Several cohort and case-control studies examined the association between fat mass (FM) and the risk of breast cancer; however, findings are conflicting. The purpose of the present study was to systematically review this association and conducted a meta-analysis, if possible.

METHOD

A systematic search of PubMed/Medline, Scopus, Web of Science and Embase databases was conducted for cohort and case-control studies, between January 2000 and 31 March 2018 with no language limitations. Multivariate adjusted relative risk (RR) estimates with 95% confidence intervals (CI) for each category of FM were pooled to examine the association.

RESULTS

Finally, 12 papers were considered for quantitative synthesis. The pooled RR for the highest vs. the lowest FM (%) of cohort studies was 1.44 (95% CI: 1.33, 1.56; I²: 63.3%, p = 0.008). The overall effect size for adjusted case-control studies showed no significant association (1.49, 95% CI: 0.77, 2.90; I²: 93.2%; p = 0.001). After stratification by menopause, it was revealed that the association between FM and the risk of breast cancer in post menopausal women (2.29, 95% CI: 1.12, 4.68; I²: 92%, p = 0.0001) was significant, while there was no significant association in pre-menopausal women (0.68, 95% CI: 0.18, 2.58; I²: 81.3%; p = 0.02).

CONCLUSION

Cohort studies showed that higher FM is positively associated with the risk for breast cancer. However, only case-control studies on post-menopausal women showed a positive link. Due to limited studies and high heterogeneity, findings should be interpreted with caution. More cohort studies are needed to clarify this association.

Abdominal Adiposity and Physical Inactivity Are Positively Associated with Breast Cancer: A Case-Control Study

OBJECTIVE

To examine whether breast cancer is associated with body composition and level of physical activity, considering the menstrual status.

METHODS

This was a case-control study with 116 women recently diagnosed with breast cancer and 226 controls. Body composition was assessed by dual-energy X-ray absorptiometry, and cardiometabolic risk was assessed by conicity index and waist-to-height ratio. The short version of the International Physical Activity Questionnaire was used to estimate the level of physical activity. All analyses were adjusted for age and BMI.

RESULTS

The total body fat percentage, android body fat, android-gynoid ratio, and waist circumference were positively associated (p < 0.05), whereas the percentage of lean body mass (p <0.05) and the level of physical activity (p < 0.01) were inversely associated with breast cancer in premenopausal women. Among postmenopausal women, physical activity decreased the chance of developing breast cancer by 49% (95% CI = 0.29 to 0.92, p = 0.02).

CONCLUSION

A low percentage of lean body mass and high abdominal adiposity in the premenopausal period increase the chances of developing breast cancer. Regular physical activity is inversely associated with breast cancer in pre- and postmenopausal women.

Examining the Associations among Fibrocystic Breast Change, Total Lean Mass, and Percent Body Fat

Fibrocystic breast change (FBC) is extremely common and occurrs in 90% of women during their lives. The association between body composition and risk of breast cancer is well established. We hypothesized that the effect might exist during the development of FBC. Our aim was to examine the relationships of total lean mass (TLM) and percent body fat (PBF) with FBC in a general female population. In total, 8477 female subjects aged 20 years or older were enrolled in the study at the Tri-Service General Hospital in Taiwan from 2011 to 2016. Comprehensive examinations including biochemical data, measurements of body composition and breast ultrasound were performed. PBF was positively associated with the presence of FBC (OR = 1.039, 95%CI: 1.018–1.060), and TLM showed the opposite result (OR = 0.893, 95%CI: 0.861–0.926). Condition of metabolic syndrome (MetS), diabetes (DM) and fatty liver modified the association between PBF and FBC (P < 0.001, P = 0.032 and P = 0.007, respectively). Female subjects diagnosed with MetS, DM, and fatty liver had higher risk of developing FBC than control subjects (OR = 1.110, 95%CI: 1.052–1.171; OR = 1.144, 95%CI: 1.024–1.278; OR = 1.049, 95%CI: 1.019, 1.080). Those with higher PBF (for highest quartile versus lowest, OR = 2.451, 95%CI: 1.523–3.944) or lower TLM (for highest quartile versus lowest, OR = 0.279, 95%CI: 0.171–0.455) had increased risk of developing FBC. In conclusion, increased PBF and reduced TLM were likely to predict the risk of the presence of FBC in a general female population.

Mate Intake and Risk of Breast Cancer in Uruguay: a Case- Control Study

Regarding 'mate' intake (infusion of Ilex paraguariensis herb, a staple beverage in temperate South American regions), most epidemiologic studies showed positive associations with risk of some cancers, (e.g. upper aerodigestive tract), but evidence on breast cancer (BC) risk is limited to a previous multi-site study, which reported a non significant odds ratio [OR]=0.85, 95% confidence interval [95% CI] 0.67-1.09, p for trend=0.31) for the highest quartile of intake. The present study was conducted in order to further assess associations of 'mate' intake with BC risk. We combined two databases of women belonging to public and private healthcare hospitals. The sample included 572 BC incident cases and 889 controls interviewed with a specific questionnaire featured by socio-demographic, reproductive and lifestyle variables, and a food frequency questionnaire of 64 items, also analyzing 'mate' intake (consumer status, daily intake, age at start, age at quit, duration of habit, intensity of intake). ORs and their 95%CI were calculated through unconditional logistic regression, adjusting for relevant potential confounders. The highest quartile of 'mate' intake was inversely associated with BC risk (OR=0.40, 95%CI 0.26-0.57, p for trend <0.001). Stratified analyses also displayed strong significant inverse associations for 'mate' in frequent tea drinkers (OR=0.22), high energy intake (OR=0.23), high body mass index (OR=0.29) and in postmenopausal women (OR=0.36), among other results. As conclusions, we found evidence of a significant inverse association for 'mate' intake and BC risk.

Obesity in breast cancer--what is the risk factor?

Environmental factors influence breast cancer incidence and progression. High body mass index (BMI) is associated with increased risk of post-menopausal breast cancer and with poorer outcome in those with a history of breast cancer. High BMI is generally interpreted as excess adiposity (overweight or obesity) and the World Cancer Research Fund judged that the associations between BMI and incidence of breast cancer were due to body fatness. Although BMI is the most common measure used to characterise body composition, it cannot distinguish lean mass from fat mass, or characterise body fat distribution, and so individuals with the same BMI can have different body composition. In particular, the relation between BMI and lean or fat mass may differ between people with or without disease. The question therefore arises as to what aspect or aspects of body composition are causally linked to the poorer outcome of breast cancer patients with high BMI. This question is not addressed in the literature. Most studies have used BMI, without discussion of its shortcomings as a marker of body composition, leading to potentially important misinterpretation. In this article we review the different measurements used to characterise body composition in the literature, and how they relate to breast cancer risk and prognosis. Further research is required to better characterise the relation of body composition to breast cancer.

Risk factors for premenopausal breast cancer: a case-control study in Uruguay

In order to thoroughly analyze risk factors of breast cancer (BC) in premenopausal Uruguayan women, a case-control study was carried out at the Pereira Rossell Women's Hospital, Montevideo, where 253 incident BC cases and 497 frequency-matched healthy controls were interviewed on menstrual and reproductive story, were administered a short food frequency questionnaire and undertook a series of body measurements necessary to calculate body composition and somatotype. Odds ratio (OR) coefficients were taken as estimates of relative risk derived from unconditional logistic regression. Among the classical risk factors, only the family history of BC in first degree relatives was significantly associated with risk of premenopausal BC (OR=2.20, 95% CI 1.33-3.62). Interestingly, this risk factor was found to be stronger in women of ages >40 (OR=4.05, 95% CI 2.10-7.81), late menarche (OR= 2.39, 95% CI 1.18-4.85), early age for their first delivery (OR=3.02, 95% CI 1.26-7.22), short time between menarche and first delivery (OR=3.22, 95% CI 1.29-8.07), and with high parity (OR=4.10, 95% CI 1.79-9.36), although heterogeneity was detected only for age and parity. High consumption of red meat was positively associated with the disease risk (OR=2.20, 95% CI 1.35-3.60), in the same way as fried foods (OR=1.79, 95% CI 1.12-2.84). Conversely, a high intake of plant foods displayed a protective effect (OR=0.41, 95% CI 0.26-0.65). Except for hypertension (OR=1.55, 95% CI 1.03-2.35), none of the analyzed components of metabolic syndrome were associated to BC risk. Particular increases of risk for premenopausal BC were found for family history in first degree relatives in certain subsets derived from the menstrual-reproductive history. Preventive strategies could broaden their scope if new studies confirm the present results, in view of the limited prevention measures that premenopausal BC currently has.

Overweight and obesity: a review of their relationship to metabolic syndrome, cardiovascular disease, and cancer in South America

Socioeconomic and demographic transformations are occurring very rapidly in some areas of the world, especially in South America, and are accompanied by changes in lifestyle, dietary patterns, and the epidemiological profile of prevalent diseases. This review examines whether obesity and overweight are related to metabolic syndrome, cardiovascular disease, and cancer in South America. Research carried out in more than 6,000 cases and controls was evaluated, along with most of the available publications related to South America. In South America, obesity and risk factors for cardiovascular disease are related mainly to aging, ethnicity effects, and preventable risky lifestyle conditions. Most of the studies that found an association between cancer and obesity are from the Southern Cone, the geographic area most affected by this pathology. Overall, the prevalence of metabolic syndrome was highest in Chile, followed in decreasing order by Colombia, Peru, Argentina, and Ecuador, with differences noted between urban and rural areas or between urban and periurban areas. Obesity and cancer may be preventable, at least in part, by healthy behavior; hence, exercise, weight control, and healthy dietary habits are important to reduce the risk of these major chronic diseases.

Diabetes, overweight and risk of postmenopausal breast cancer: a case-control study in Uruguay

Obese postmenopausal women increase their risk of developing breast cancer (BC), in particular if they display an android-type pattern of adiposity, which is also associated to increased risks of diabetes mellitus, hypertension and cardiovascular disease. In order to explore the associations among anthropometry (body mass index, body composition, somatotype), some specific items of medical history (diabetes, hypertension, dislypidemias, hyperuricemia) and the risk of BC in Uruguayan women, a case-control study was carried out between 2004-2009 at our Oncology Unit. 912 women of ages between 23-69 years (367 new BC cases and 545 non hospitalized, age-matched controls with a normal mammography) were interviewed. Twenty body measurements were taken in order to calculate body composition and somatotype. Patients were queried on socio-demographics, reproductive history, family history of cancer, a brief food frequency questionnaire and on personal history of diabetes, dislypidemias, hyperuricemia, hypertension and gallbladder stones. Uni- and multivariate analyses were done, generating odds ratios (ORs) as an expression of relative risks. A personal history of diabetes was positively associated to BC risk (OR=1.64, 95% CI 1.00-2.69), being higher among postmenopausal women (OR=1.92, 95% CI 1.04-3.52). The risks of BC for diabetes in postmenopausal women with overweight combined with dislypidemia (OR=9.33, 95% CI 2.10-41.5) and high fat/muscle ratio (OR=7.81, 95% CI 2.01-30.3) were significantly high. As a conclusion, a personal history of diabetes and overweight was strongly associated to BC. The studied sample had a subset of high-risk of BC featured by postmenopausal overweight and diabetic women, who also had a personal history of hypertension and/or dyslipidemia. The present results could contribute to define new high risk groups and individuals for primary as well as for secondary prevention, since this pattern linked to the metabolic syndrome is usually not considered for BC prevention.

Hormonal and metabolic modulation through nutrition: towards a primary prevention of breast cancer

Breast cancer (BC) is a polygenic and multifactorial disease for which estrogens have been recognized as the main risk factor, and for which lifestyle plays a key role. Previous epidemiologic cancer research performed in Uruguayan population delimited its dietary and anthropometric profiles. Recognizing the difficulty for universalizing a nutritional basis for prevention due to different eating patterns among regions and countries, we summarize the existent knowledge linking nutrition, estrogens, metabolism and BC. As an attempt towards primary prevention of BC, we present recommendations mainly based on country-specific research findings and modifiable putative risk and protective factors, proposing to modify the intake of meats and other fatty foods--especially sources of Ω-6 and Ω-3 fatty acids--adding olive oil, selected vegetables, citrus fruits and working towards adequate body fat/muscle proportions. From a medical and ethical viewpoint, it is justified to recommend certain nutritional changes to women, because no adverse side effects are expected to occur.