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

The association between adiposity indices and the odds of breast cancer based on findings from a case control study

Adiposity is a major risk factor for the development of cancers, such as breast cancer(BC) in adults. However, the role of central adiposity or general obesity as primary predictors of BC occurrence and progression is not well-established. Therefore, the current study aimed to assess the association between various adiposity indices, including a body shape index(ABSI), abdominal volume index(AVI), body roundness index(BRI), conicity index(CI), body adiposity index(BAI), reciprocal ponderal index(RPI), and waist to height0.5 ratio(WHt0.5R) as surrogates for predicting the odds of BC in adult women. This case-control study was conducted at Shohada and Imam Hossain hospitals in Tehran and included 134 newly diagnosed BC cases and 267 controls. Anthropometric variables, including weight, height, and waist circumference were measured using standard methods, and various adiposity indices were calculated accordingly. The odds ratios(ORs) with 95% confidence intervals(CIs) for BC were reported across tertiles of adiposity indices using multivariable logistic regression. Participants in the highest tertile of BRI(OR:2.07;95% CI:1.04-4.12), BAI(OR:2.06;95% CI:1.05-4.03), and WHt0.5R(OR:1.81;95% CI:1.01-3.55) had significantly higher odds of BC compared to those in the lowest tertile(P < 0.05). Additionally, each SD increase in RPI was associated with lower odds of BC(OR:0.77;95% CI:0.61-0.98,P = 0.034). However, no significant associations were observed for CI, AVI, and ABSI with the odds of BC. Our results suggest that WHtR, BRI, BAI, and WHt0.5R may be more effective predictors of BC odds among the evaluated adiposity indices.

The relationship between central obesity and risk of breast cancer: a dose-response meta-analysis of 7,989,315 women

Purpose

Central obesity may contribute to breast cancer (BC); however, there is no dose-response relationship. This meta-analysis examined the effects of central obesity on BC and their potential dose-response relationship.

Methods

In the present study, PubMed, Medline, Embase, and Web of Science were searched on 1 August 2022 for published articles. We included the prospective cohort and case-control studies that reported the relationship between central obesity and BC. Summary effect size estimates were expressed as risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (95% CI) and were evaluated using random-effect models. The inconsistency index (I2) was used to quantify the heterogeneity magnitude derived from the random-effects Mantel-Haenszel model.

Results

This meta-analysis included 57 studies (26 case-control and 31 prospective cohort) as of August 2022. Case-control studies indicated that waist circumference (WC) (adjusted OR = 1.18; 95% CI: 1.00-1.38; P = 0.051) and waist-to-hip ratio (WHR) (adjusted OR = 1.28; 95% CI: 1.07-1.53; P = 0.008) were significantly positively related to BC. Subgroup analysis showed that central obesity measured by WC increased the premenopausal (adjusted OR = 1.15; 95% CI: 0.99-1.34; P = 0.063) and postmenopausal (adjusted OR = 1.18; 95% CI: 1.03-1.36; P = 0.018) BC risk and the same relationship appeared in WHR between premenopausal (adjusted OR = 1.38; 95% CI: 1.19-1.59; P < 0.001) and postmenopausal (adjusted OR = 1.41; 95% CI: 1.22-1.64; P < 0.001). The same relationship was observed in hormone receptor-positive (HR+) (adjusted ORWC = 1.26; 95% CI: 1.02-1.57; P = 0.035, adjusted ORWHR = 1.41; 95% CI: 1.00-1.98; P = 0.051) and hormone receptor-negative (HR-) (adjusted ORWC = 1.44; 95% CI: 1.13-1.83; P = 0.003, adjusted ORWHR = 1.42; 95% CI: 0.95-2.13; P = 0.087) BCs. Prospective cohort studies indicated that high WC (adjusted RR = 1.12; 95% CI: 1.08-1.16; P < 0.001) and WHR (adjusted RR = 1.05; 95% CI: 1.018-1.09; P = 0.017) may increase BC risk. Subgroup analysis demonstrated a significant correlation during premenopausal (adjusted RR = 1.08; 95% CI: 1.02-1.14; P = 0.007) and postmenopausal (adjusted RR = 1.14; 95% CI: 1.10-1.19; P < 0.001) between BC and central obesity measured by WC, and WHR was significantly positively related to BC both premenopausal (adjusted RRpre = 1.04; 95% CI: 0.98-1.11; P = 0.169) and postmenopausal (adjusted RRpost = 1.04; 95% CI: 1.02-1.07; P = 0.002). Regarding molecular subtype, central obesity was significantly associated with HR+ (adjusted ORWC = 1.13; 95% CI: 1.07-1.19; P < 0.001, adjusted ORWHR = 1.03; 95% CI: 0.98-1.07; P = 0.244) and HR- BCs (adjusted ORWC =1.11; 95% CI: 0.99-1.24; P = 0.086, adjusted ORWHR =1.01; 95% CI: 0.91-1.13; P = 0.808). Our dose-response analysis revealed a J-shaped trend in the relationship between central obesity and BC (measured by WC and WHR) in case-control studies and an inverted J-shaped trend between BMI (during premenopausal) and BC in the prospective cohort.

Conclusion

Central obesity is a risk factor for premenopausal and postmenopausal BC, and WC and WHR may predict it. Regarding the BC subtype, central obesity is proven to be a risk of ER+ and ER- BCs. The dose-response analysis revealed that when BMI (during premenopausal) exceeded 23.40 kg/m2, the risk of BC began to decrease, and WC higher than 83.80 cm or WHR exceeded 0.78 could efficiently increase the BC risk.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022365788.

Body Fat Distribution and Female Infertility: a Cross-Sectional Analysis Among US Women

At present, the effect of body fat distribution on female reproductive health is still inconclusive. The purpose of our study was to analyze the correlation between female infertility rates and the fat mass portion of the android region to the gynoid region (the A/G ratio) among US women of reproductive age. Female infertility is defined as a failure to get pregnant after 12 months of unprotected sexual activity. A total of 3434 women of reproductive age were included in this study as part of the 2013-2018 National Health and Nutrition Examination Survey (NHANES). The A/G ratio was used to assess the body fat distribution of participants. Based on the comprehensive study design and sample weights, it was determined that the A/G ratio was associated with female infertility primarily through logistic regression analyses. After adjusting for potential confounders, the multivariate regression analysis indicated an increase in the A/G ratio was correlated with an increase in the prevalence of female infertility (OR = 4.374, 95% CI:1.809-10.575). Subgroup analyses showed an increased prevalence of infertility in non-Hispanic Whites (P = 0.012), non-diabetic individuals (P = 0.008), individuals under 35 years old (P = 0.002), and individuals with secondary infertility (P = 0.01). The trend tests and smooth curve fitting illustrate a linear trend between the A/G ratio and female infertility. Future researches are warranted to confirm the causal relationship between body fat distribution and female infertility, which may provide an insight into future prevention and treatment of female infertility.

Long-Term Exposure to Walkable Residential Neighborhoods and Risk of Obesity-Related Cancer in the New York University Women's Health Study (NYUWHS)

BACKGROUND

Living in neighborhoods with higher levels of walkability has been associated with a reduced risk of obesity and higher levels of physical activity. Obesity has been linked to increased risk of 13 cancers in women. However, long-term prospective studies of neighborhood walkability and risk for obesity-related cancer are scarce.

OBJECTIVES

We evaluated the association between long-term average neighborhood walkability and obesity-related cancer risk in women.

METHODS

The New York University Women's Health Study (NYUWHS) is a prospective cohort with 14,274 women recruited between 1985 and 1991 in New York City and followed over nearly three decades. We geocoded residential addresses for each participant throughout follow-up and calculated an average annual measure of neighborhood walkability across years of follow-up using data on population density and accessibility to destinations associated with geocoded residential addresses. We used ICD-9 codes to characterize first primary obesity-related cancers and employed Cox proportional hazards models to assess the association between average neighborhood walkability and risk of overall and site-specific obesity-related cancers.

RESULTS

Residing in neighborhoods with a higher walkability level was associated with a reduced risk of overall and site-specific obesity-related cancers. The hazards ratios associated with a 1-standard deviation increase in average annual neighborhood walkability were 0.88 (95% CI: 0.85, 0.93) for overall obesity-related cancer, 0.89 (95% CI: 0.84, 0.95) for postmenopausal breast cancer, 0.82 (95% CI: 0.68, 0.99) for ovarian cancer, 0.87 (95% CI: 0.76, 0.99) for endometrial cancer, and 0.68 (95% CI: 0.49, 0.94) for multiple myeloma, adjusting for potential confounders at both the individual and neighborhood level. The association between neighborhood walkability and risk of overall obesity-related cancer was stronger among women living in neighborhoods with higher levels of poverty compared with women living in areas with lower poverty levels (p Interaction = 0.006 ).

DISCUSSION

Our study highlights a potential protective role of neighborhood walkability in preventing obesity-related cancers in women. https://doi.org/10.1289/EHP11538.

Risk factors for breast cancer and their association with molecular subtypes in a population of Northeast Brazil

BACKGROUND

The risk factors for breast cancer (BC) among women in Brazilian populations are poorly understood. To date, few Brazilian studies have addressed the potential association between risk factors and molecular BC subtypes. This case-control study aimed to identify risk factors for BC in a population of Northeast Brazil.

METHODS

Data from 313 patients with invasive BC and 321 healthy controls were obtained from medical records from two cancer treatment centres and personal interviews. Of the 313 BC patients, 224 (71.6%) had reached menopause. The following distribution of subtypes was found among 301 patients: (1) Luminal A: 54 (17.9%); (2) Luminal B: 175 (58.1%); (3) HER2/neu: 29 (9.7%); and (4) triple-negative breast cancer (TNBC): 43 (14.3%). Odds ratios (ORs) and confidence intervals (CIs) were determined using regression analysis.

RESULTS

Regression modelling indicated that family history, obesity (≥ 30.0 kg/m²), alcohol consumption and contraceptive use increased the overall risk of BC 1.78 (95% CI: 1.22-2.59), 1.69 (95% CI: 1.08-2.63), 2.21 (95% CI: 1.44-3.39) and 2.99 (95% CI: 2.09-4.28) times, respectively. After stratification for menopausal status, alcohol consumption increased the risk of BC 4.15 (95% CI: 2.13-8.11) times, and obesity, as a single variable, increased the risk of BC 2.02 (95% CI: 1.22-3.37) times, only among postmenopausal women. In a case-control analysis, the risk of TNBC and Luminal B breast cancer were 4.06 (95% CI: 1.58-10.42) and 1.87 times (95% CI: 1.13-3.11) higher, respectively, in obese women than in non-obese women. Furthermore, alcohol consumption increased the risk of Luminal A and B subtypes 7.08 (3.40-14.73) and 1.77 (1.07-2.92) times, respectively.

CONCLUSION

Family history, contraceptive use, obesity and alcohol consumption increased the risk of BC. Obesity and alcohol consumption differentially increased risk of TNBC and Luminal molecular subtypes.

Cancer Etiology and Prevention Principle: "1 + X"

Cancer was previously thought to be an inevitable aspect of human health with no effective treatments. However, the results of in-depth cancer research suggest that most types of cancer may be preventable. Therefore, a comprehensive understanding of the disparities in cancer burden caused by different risk factors is essential to inform and improve cancer prevention and control. Here, we propose the cancer etiology and prevention principle "1 + X," where 1 denotes the primary risk factor for a cancer and X represents the secondary contributing risk factors for the cancer. We elaborate upon the "1 + X" principle with respect to risk factors for several different cancer types. The "1 + X" principle can be used for precise prevention of cancer by eliminating the main cause of a cancer and minimizing the contributing factors at the same time.

Molecular epigenetic dynamics in breast carcinogenesis

Breast cancer has become one of the most common dreadful diseases that target women across the globe. The most obvious reasons we associate with it are either genetic mutations or dysregulation of pathways. However, there is yet another domain that has a significant role in influencing the genetic mutations and pathways. Epigenetic mechanisms influence these pathways either independently or in association with genetic mutations, thereby expediting the process of breast carcinogenesis. Breast cancer is governed by various transduction pathways such as PI3K/AKT/mTOR, NOTCH, β Catenin, NF-kB, Hedgehog, etc. There are many proteins as well that serve to be tumor suppressors but somehow lose their ability to function. This may be because of either genetic mutation or a process that represses their function. Apart from these, there are a lot of individual factors like puberty, breastfeeding, abortion, parity, circadian rhythm, alcohol consumption, pollutants, and obesity that drive these mutations and hence alter the pathways. Epigenetic mechanisms like DNA methylation, histone modifications, and lncRNAs directly or indirectly bring alterations in the proteins that are involved in the pathways. They do this by either promoting the transcription of genes or by repressing it at the ground genetic level that advances breast carcinogenesis. Epigenetics precedes genetic mutation in driving carcinogenesis and so, it needs to be explored further to diversify the possibilities of target specific treatments. In this review, the general role of DNA methylation, histone modification, and lncRNAs in breast cancer and their role in influencing the oncogenic signaling pathways along with the various factors governing them have been discussed for a better understanding of the role of epigenetics in breast carcinogenesis.

The Weight of Racial Discrimination: Examining the Association Between Racial Discrimination and Change in Adiposity Among Emerging Adult Women Enrolled in a Behavioral Weight Loss Program

BACKGROUND

Non-Hispanic Black (NHB) emerging adult (EA) women are at disproportionate risk for obesity but experience limited benefit from behavioral weight loss (BWL) programs. Race-related stress could play a role; the goal of this study was to examine the association between racial discrimination (RD) and early (3 months) changes in adiposity, and to explore potential protective factors, among EA in an adapted BWL program.

METHODS

This is an ancillary study of non-Hispanic White (NHW) and NHB EA women enrolled in an adapted BWL trial (N = 49; 55.1% NHB; Age 21.2 (2.1); BMI = 33.0 + 4.3 kg/m²). At baseline, group- and personal-level RD (RD-group and RD-personal), racial identity (NHB women only), vigilant coping, and social support were assessed via validated questionnaires. Weight and waist circumference were measured objectively at 0 and 3 months.

RESULTS

NHW women manifested greater reductions in waist circumference relative to NHB women (p = .004). RD-personal did not predict change in waist circumference at 3 months (p = .402); however, the association between RD-group and change in waist circumference was statistically significant (p = .015), such that reporting greater group-level discrimination predicted a smaller decrease in waist circumference; the model explained 22% of the variance. Social support and vigilant coping were not statistically significant in the model. Among NHB women only, higher racial identity-centrality predicted greater reduction in waist circumference (p = .019).

CONCLUSION

Findings suggest racial discrimination could contribute to greater cardiometabolic risk during this developmental period. Future research should examine how experiences of racial discrimination unfold in the daily lives of NHB women to inform mechanistic interventions to enhance health and well-being.

TRIAL REGISTRATION

NCT02736981. Low Intensity Weight Loss for Young Adults.

Chemotherapy negatively impacts body composition, physical function and metabolic profile in patients with breast cancer

BACKGROUND

Evidence suggests that chemotherapy (CT) leads to unfavorable outcomes on nutritional and metabolic profile; however, this is poorly understood.

OBJECTIVE

To evaluate the impact of CT on body composition, bone mineral density (BMD), insulin resistance, lipid markers related to atherosclerotic cardiovascular diseases in women recently diagnosed with breast cancer according to menopausal status.

METHODS

This is a prospective study that enrolled women newly diagnosed with stage II-III breast cancer (2014-18). Body composition were measured by dual-energy x-ray absorptiometry. Blood samples were collected to assess lipid profile, insulin resistance and sensitivity, visceral adiposity index and lipid accumulation product were calculated. Dietary intake, physical activity and function were also evaluated at the time of breast cancer diagnosis and after CT completion.

RESULTS

Ninety-nine women (40.4% in the premenopausal stage) aged 51 ± 1 years took part in this study. CT duration was 197 ± 27 days and main regimen was anthracyclines with taxanes (88.9%). CT was associated with an increase in total and central adiposity, insulin resistance, and all lipid-related markers, and a decrease in appendicular lean mass index, BMD and HDL-c concentration. Premenopausal women experienced greater unfavorable outcomes on adiposity markers and BMD compared to postmenopausal women (p < 0.01). No changes were observed in dietary intake and physical activity after CT.

CONCLUSIONS

Breast cancer CT negatively impacted body composition and metabolic profile. Premenopausal women experienced greater unfavorable impact on adiposity markers and BMD.

Physical Inactivity and Pancreatic Cancer Mortality

OBJECTIVE

To determine the association between pre-diagnostic recreational physical inactivity (RPI) and pancreatic cancer (PC) mortality.

METHODS

This analysis included 107 patients seen at Roswell Park Comprehensive Cancer Center diagnosed with PC between 1989 and 1998. Cox proportional hazards models were used to determine hazard ratios (HR) and 95% confidence intervals (CI) for PC mortality associated with self-reported pre-diagnostic RPI. Models were adjusted for known prognostic factors, including age, sex, stage at diagnosis, smoking status, and body mass index (BMI). Results were also stratified by sex, BMI, smoking status, histology, and treatment status.

RESULTS

We observed a significant association between RPI and PC mortality in all patients (HR = 1.72, 95% CI = 1.06-2.79), as well as among overweight or obese patients (HR = 2.74, 95% 95% CI = 1.42-5.29), females (HR = 2.63; 95% CI, 1.08-6.39), and non-smokers (HR = 1.72; 95% CI, 1.02-2.89).

CONCLUSION

These results suggest that RPI prior to PC diagnosis is associated with a higher risk of death. Future studies with larger sample sizes are needed to explore whether this association varies across tumor histology.

Trends in the Incidence of Breast Cancer Following the Radiological Accident in Goiânia: A 25-Year Analysis

Background:

The largest radiological accident to occur in any urban area happened in Goiânia, Brazil, in 1987. One major concern regarding deleterious effects in the population was a possible increase in the breast cancer incidence. This study analyzed trends in the incidence of breast cancer over the 25-year period following the radiological accident.

Methods:

This ecological, population-based study was conducted to determine the incidence of breast cancer in female residents of Goiânia, Goiás, Brazil, between 1988 and 2012. The data were collected from the Goiânia population-based cancer registry. Crude and age-standardized incidence rates were calculated. The Joinpoint software program was used to calculate annual percent changes (APC) in the incidence of breast cancer.

Results:

Overall, 7,365 new cases of breast cancer were identified, with an annual crude incidence rate of 23.09/100,000 women in 1988 and of 71.65/100,000 women in 2012. The age-standardized incidence rate was 35.63/100,000 women in 1988 and 65.63/100,000 women in 2012. Analysis of the APC showed a significant annual increase of 4.8% in the incidence between 1988 and 2005 (p<0.0001) followed by stabilization in 2005-2012, with an APC of -3.5% (p=0.1).

Conclusion:

There was an increase in the incidence of breast cancer in the female residents of Goiânia, Goiás in the first 17 years of evaluation (1988-2004) followed by a period of stabilization until 2012. However, the trends in the incidence suggest a lack of association with the radiological accident.

Sedentary Behavior and Alcohol Consumption Increase Breast Cancer Risk Regardless of Menopausal Status: A Case-Control Study

Identification of modifiable risk factors for breast cancer is critical for primary prevention of the disease. The aim of this study was to evaluate how certain lifestyle variables modify the chances of developing breast cancer based on menopausal status. A case-control study was performed in a group of 542 women, 197 who were diagnosed with breast cancer and 344 control individuals. The groups were matched by age, body mass index, and menopausal status. Participants were evaluated for level of physical activity, alcohol consumption, smoking habit, weight, height, and waist circumference (WC). A multivariate logistic regression model was used to estimate odds ratios and 95% confidence intervals (95% CI). Regular consumption of alcoholic beverages (2.91, 95% CI 1.58-5.38 and 1.86, 95% CI 1.15-3.03) and sedentary behavior (2.08; 95% CI 1.12-3.85 and 1.81; 95% CI 1.12-2.94) were associated with breast cancer risk in pre- and postmenopausal women, respectively. High WC (3.31, 95% CI 1.45-7.55) was associated with an increased risk of developing breast cancer in premenopausal women. While in postmenopausal women, current smoking (2.43, 95% CI 1.01-5.83) or previous history of smoking (1.90; 95% CI 1.14-3.14) increased the chances of developing breast cancer. Sedentary behavior and current consumption of alcoholic beverages were more likely to increase the risk of developing breast cancer regardless of menopausal status.