Body fatness and breast cancer risk in women of African ancestry

Comparing patient-reported outcomes and lifestyle factors before and after the COVID-19 pandemic among Black and Hispanic breast cancer survivors in New Jersey

PURPOSE

The impact of the COVID-19 pandemic restrictions in the US since March 2020 on cancer survivorship among Black and Hispanic breast cancer (BC) survivors remains largely unknown. We aimed to evaluate associations of the pandemic with participant characteristics, patient-reported outcomes (PROs), and lifestyle factors among Black and Hispanic BC survivors in the Women's Circle of Health Follow-Up Study and the New Jersey BC Survivors Study.

METHODS

We included 447 Black (npre = 364 and npost = 83) and 182 Hispanic (npre = 102 and npost = 80) BC survivors who completed a home interview approximately 24 months post-diagnosis between 2017 and 2023. The onset of the pandemic was defined as March 2020. The association of the pandemic with binary outcomes was estimated using robust Poisson regression models.

RESULTS

Hispanic and Black BC survivors recruited after the onset of the pandemic reported higher socioeconomic status and fewer comorbidities. Black women in the post-pandemic group reported a higher prevalence of clinically significant sleep disturbance (prevalence ratio (PR) 1.43, 95% CI 1.23, 1.68), lower sleep efficiency, and lower functional well-being, compared to the pre-pandemic group. Hispanic women were less likely to report low health-related quality of life (vs. high; PR 0.62, 95% CI 0.45, 0.85) after the onset of the pandemic.

CONCLUSIONS

Ongoing research is crucial to untangle the impact of the pandemic on racial and ethnic minorities participating in cancer survivorship research, as well as PROs and lifestyle factors.

IMPLICATIONS FOR CANCER SURVIVORS

This study highlights the importance of considering the impact of the pandemic in all aspects of research, including the interpretation of findings.

Adiposity, Body Composition Measures, and Breast Cancer Risk in Korean Premenopausal Women

Objective

To investigate the association between body composition parameters and breast cancer (BC) risk in premenopausal women.

Design, Setting, and Participants

Prospective cohort study using data from the Kangbuk Samsung Cohort Study. Participants were women aged 20 to 54 years who were enrolled from 2011 to 2019 and followed up for BC development until December 31, 2020. Data were analyzed from June to August 2023.

Exposures

Trained nurses conducted anthropometric measurements and assessed body composition using segmental bioelectric impedance analysis. The analysis encompassed adiposity measures such as body mass index (BMI), waist circumference, and body composition parameters, including muscle mass, fat mass, ratio of muscle mass to weight, ratio of fat mass to weight, and fat mass index.

Main outcomes and measures

Adjusted hazard ratios (aHR) for BC during the follow-up period.

Results

Among 125 188 premenopausal women, the mean (SD) age was 34.9 (6.3) years. During a mean (range) follow-up of 6.7 (0.5-9.9) years, 1110 incident BC cases were identified. The mean (SD) BMI and waist circumference were 21.6 (3.1) and 75.3 (8.2) cm, respectively. Higher BMI and waist circumference were associated with decreased risk, with an aHR of 0.89 (95% CI, 0.84-0.95) per SD increase in BMI and 0.92 (95% CI, 0.86-0.98) per SD increase in waist circumference. A higher ratio of fat mass to weight was associated with decreased BC risk (aHR, 0.92; 95% CI, 0.86-0.99 per SD increase), whereas the opposite trend was observed for the ratio of muscle mass to weight, with an aHR of 1.08 (95% CI, 1.02-1.15) per SD increase. The results remained consistent even after additional adjustments for height in the model. The fat mass index was also inversely associated with BC risk, with an HR of 0.90 (95% CI, 0.85-0.97) per SD increase.

Conclusions and Relevance

In this cohort study of premenopausal women, a higher level of adiposity, represented by increased BMI, waist circumference, and fat mass, was consistently associated with decreased breast cancer risk. Conversely, muscle mass and its ratio to weight displayed opposite or inconsistent patterns. These findings suggest an inverse association between excess adiposity and the risk of BC in premenopausal women, confirming earlier findings that BMI is an indirect measure of adiposity.

Association of physical weight statuses defined by body mass index (BMI) with molecular subtypes of premenopausal breast cancer: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

The association between overweight/obesity and postmenopausal breast cancer has been proven. However, uncertainty exists regarding the association between physical weight statuses and premenopausal breast cancer subtypes. This study aimed to explore the association of body weight statuses with molecular subtypes of premenopausal breast cancer.

METHOD

A systematic search of Medline, PubMed, Embase, and Web of Science was performed. The Newcastle-Ottawa Scale (NOS) and the Joanna Briggs Institute (JBI) Critical Appraisal tools were used to evaluate the quality of the literature. STATA and R software were used to analyze the extracted data.

RESULT

The meta-analysis included 35 observational studies with a total of 41,049 premenopausal breast cancer patients. The study showed that the proportion of underweight patients was 4.8% (95% CI = 3.9-5.8%, P = 0.01), overweight was 29% (95%CI = 27.1-30.9%, P < 0.01), obesity was 17.8% (95% CI = 14.9-21.2%, P < 0.0001), and normal weight was 51.6% (95% CI = 46.7-56.5%, P < 0.0001). The pooled results showed that in comparison to the normal weight group, being physically underweight is related to a 1.44-fold risk (OR = 1.44, 95%CI = 1.28-1.63, P < 0.0001) of HER2 + breast cancer. Overweight is related to a 1.16-fold risk (OR = 1.16, 95%CI = 1.06-1.26, P = 0.002) of TNBC and a 16% lower risk (OR = 0.84, 95%CI = 0.75-0.93, P = 0.001) of ER + breast cancer. When compared to underweight/normal weight populations, both overweight (OR = 0.74, 95%CI = 0.56-0.97, P = 0.032) and obesity (OR = 0.70, 95%CI = 0.50-0.98, P = 0.037) can reduce the risk of ER + PR + breast cancer.

CONCLUSION

In the premenopausal breast cancer population, the distribution of patients' numbers with different weight statuses was significantly distinct among the various breast cancer subtypes. Additionally, the associations between physical weight statuses and the risk of premenopausal breast cancer subtypes are divergent.

mTOR pathway candidate genes and energy intake interaction on breast cancer risk in Black women from the Women's Circle of Health Study

BACKGROUND

Excessive energy intake has been shown to affect the mammalian target of the rapamycin (mTOR) signaling pathway and breast cancer risk. It is not well understood whether there are gene-environment interactions between mTOR pathway genes and energy intake in relation to breast cancer risk.

METHODS

The study included 1642 Black women (809 incident breast cancer cases and 833 controls) from the Women's Circle of Health Study (WCHS). We examined interactions between 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes and quartiles of energy intake in relation to breast cancer risk overall and by ER- defined subtypes using Wald test with a 2-way interaction term.

RESULTS

AKT1 rs10138227 (C > T) was only associated with a decreased overall breast cancer risk among women in quartile (Q)2 of energy intake, odds ratio (OR) = 0.60, 95% confidence interval (CI) 0.40, 0.91 (p-interaction = 0.042). Similar results were found in ER- tumors. AKT rs1130214 (C > A) was associated with decreased overall breast cancer risk in Q2 (OR = 0.63, 95% CI 0.44, 0.91) and Q3 (OR = 0.65, 95% CI 0.48, 0.89) (p-interaction = 0.026). HIF-1α C1772T rs11549465 (C > T) was associated with decreased overall breast cancer risk in Q4 (OR = 0.29, 95% CI 0.14, 0.59, p-interaction = 0.007); the results were similar in ER+ tumors. These interactions became non-significant after correction for multiple comparisons.

CONCLUSION

Our findings suggest that mTOR genetic variants may interact with energy intake in relation to breast cancer risk, including the ER- subtype, in Black women. Future studies should confirm these findings.

mTOR pathway candidate genes and physical activity interaction on breast cancer risk in black women from the women's circle of health study

BACKGROUND

Physical activity has been shown to affect the mammalian target of rapamycin (mTOR) signaling pathway and consequently breast carcinogenesis. Given that Black women in the USA are less physically active, it is not well understood whether there are gene-environment interactions between mTOR pathway genes and physical activity in relation to breast cancer risk in Black women.

METHODS

The study included 1398 Black women (567 incident breast cancer cases and 831 controls) from the Women's Circle of Health Study (WCHS). We examined interactions between 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes with levels of vigorous physical activity in relation to breast cancer risk overall and by ER-defined subtypes using Wald test with 2-way interaction term and multivariable logistic regression.

RESULTS

AKT1 rs10138227 (C > T) and AKT1 rs1130214 (C > A) were only associated with a decreased risk of ER + breast cancer among women with vigorous physical activity (odds ratio [OR] = 0.15, 95% confidence interval (CI) 0.04, 0.56, for each copy of the T allele, p-interaction = 0.007 and OR = 0.51, 95% CI 0.27, 0.96, for each copy of the A allele, p-interaction = 0.045, respectively). MTOR rs2295080 (G > T) was only associated with an increased risk of ER + breast cancer among women with vigorous physical activity (OR = 2.24, 95% CI 1.16, 4.34, for each copy of the G allele; p-interaction = 0.043). EIF4E rs141689493 (G > A) was only associated with an increased risk of ER- breast cancer among women with vigorous physical activity (OR = 20.54, 95% CI 2.29, 184.17, for each copy of the A allele; p-interaction = 0.003). These interactions became non-significant after correction for multiple testing (FDR-adjusted p-value > 0.05).

CONCLUSION

Our findings suggest that mTOR genetic variants may interact with physical activity in relation to breast cancer risk in Black women. Future studies should confirm these findings.

mTOR pathway candidate genes and obesity interaction on breast cancer risk in black women from the Women's Circle of Health Study

BACKGROUND

Obesity is known to stimulate the mammalian target of rapamycin (mTOR) signaling pathway and both obesity and the mTOR signaling pathway are implicated in breast carcinogenesis. We investigated potential gene-environment interactions between mTOR pathway genes and obesity in relation to breast cancer risk among Black women.

METHODS

The study included 1,655 Black women (821 incident breast cancer cases and 834 controls) from the Women's Circle of Health Study (WCHS). Obesity measures including body mass index (BMI); central obesity i.e., waist circumference (WC) and waist/hip ratio (WHR); and body fat distribution (fat mass, fat mass index and percent body fat) were obtained by trained research staff. We examined the associations of 43 candidate single-nucleotide polymorphisms (SNPs) in 20 mTOR pathway genes with breast cancer risk using multivariable logistic regression. We next examined interactions between these SNPs and measures of obesity using Wald test with 2-way interaction term.

RESULTS

The variant allele of BRAF (rs114729114 C > T) was associated with an increase in overall breast cancer risk [odds ratio (OR) = 1.81, 95% confidence interval (CI) 1.10-2.99, for each copy of the T allele] and the risk of estrogen receptor (ER)-defined subtypes (ER+ tumors: OR = 1.83, 95% CI 1.04,3.29, for each copy of the T allele; ER- tumors OR = 2.14, 95% CI 1.03,4.45, for each copy of the T allele). Genetic variants in AKT, AKT1, PGF, PRKAG2, RAPTOR, TSC2 showed suggestive associations with overall breast cancer risk and the risk of, ER+ and ER- tumors (range of p-values = 0.040-0.097). We also found interactions of several of the SNPs with BMI, WHR, WC, fat mass, fat mass index and percent body fat in relation to breast cancer risk. These associations and interactions, however, became nonsignificant after correction for multiple testing (FDR-adjusted p-value > 0.05).

CONCLUSION

We found associations between mTOR genetic variants and breast cancer risk as well as gene and body fatness interactions in relation to breast cancer risk. However, these associations and interactions became nonsignificant after correction for multiple testing. Future studies with larger sample sizes are required to confirm and validate these findings.

Association Between Recreational Physical Activity and mTOR Signaling Pathway Protein Expression in Breast Tumor Tissue

Physical activity (PA) is associated with decreased signaling in the mTOR pathway in animal models of mammary cancer, which may indicate favorable outcomes. We examined the association between PA and protein expression in the mTOR signaling pathway in breast tumor tissue. Data on 739 patients with breast cancer, among which 125 patients had adjacent-normal tissue, with tumor expression for mTOR, phosphorylated (p)-mTOR, p-AKT, and p-P70S6K were analyzed. Self-reported recreational PA levels during the year prior to diagnosis were classified using the Centers for Disease Control and Prevention guideline as sufficient (for moderate or vigorous) PA or insufficient PA (any PA but not meeting the guideline) or no PA. We performed linear models for mTOR protein and two-part gamma hurdle models for phosphorylated proteins. Overall, 34.8% of women reported sufficient PA; 14.2%, insufficient PA; 51.0%, no PA. Sufficient (vs. no) PA was associated with higher expression for p-P70S6K [35.8% increase; 95% confidence interval (CI), 2.6-80.2] and total phosphoprotein (28.5% increase; 95% CI, 5.8-56.3) among tumors with positive expression. In analyses stratified by PA intensity, sufficient versus no vigorous PA was also associated with higher expression levels of mTOR (beta = 17.7; 95% CI, 1.1-34.3) and total phosphoprotein (28.6% higher; 95% CI, 1.4-65.0 among women with positive expression) in tumors. The study found that guideline-concordant PA levels were associated with increased mTOR signaling pathway activity in breast tumors. Studying PA in relation to mTOR signaling in humans may need to consider the complexity of the behavioral and biological factors.

Significance

PA increases energy expenditure and limits energy utilization in the cell, which can influence the mTOR pathway that is central to sensing energy influx and regulating cell growth. We studied exercise-mediated mTOR pathway activities in breast tumor and adjacent-normal tissue. Despite the discrepancies between animal and human data and the limitations of our approach, the findings provide a foundation to study the mechanisms of PA and their clinical implications.

Anthropometric measures and breast cancer risk among Hispanic women in Puerto Rico

INTRODUCTION

Increased risk of postmenopausal breast cancer associated with anthropometric measures including Body Mass Index (BMI), adult weight gain, and waist circumference has been observed in North American and European populations, but little evidence is available for Hispanic women. Breast cancer is the leading type of cancer, and leading cause of cancer-related deaths among Hispanic women in Puerto Rico (PR). However, compared with the United States, breast cancer incidence rates are lower but increasing more rapidly.

PURPOSE

To examine associations between anthropometric characteristics and breast cancer risk in Hispanic women in PR.

METHODS

Data from a population-based case-control study in the San Juan metropolitan region (cases = 315; controls = 348) were used to examine associations between anthropometric measures and breast cancer risk, also considering menopausal status and hormone therapy (HT).

RESULTS

Among premenopausal participants, there was a significant trend for lower odds of breast cancer with higher BMI and borderline significant with higher waist to height ratio (WHtR). For postmenopausal participants, a significant trend for lower odds of breast cancer was observed with higher WHtR, and waist to hip ratio (WHR), borderline significant with higher BMI, and higher odds with height. Among postmenopausal participants using HT, a significant trend for lower odds of breast cancer was observed with higher waist circumference, WHtR, WHR, and body shape index.

CONCLUSION

Our study provides evidence of anthropometric differences in relation to breast cancer risk in PR compared to previous studies. Future studies should include analyses of fat and lean mass distribution, and hormone receptor status to further understand anthropometry and breast cancer risk among Hispanic women.

Association of Obesity and Diabetes With the Incidence of Breast Cancer in Louisiana

INTRODUCTION

Breast cancer is a heterogeneous disease, consisting of multiple molecular subtypes. Obesity has been associated with an increased risk for postmenopausal breast cancer, but few studies have examined breast cancer subtypes separately. Obesity is often complicated by type 2 diabetes, but the possible association of diabetes with specific breast cancer subtypes remains poorly understood.

METHODS

In this retrospective case-control study, Louisiana Tumor Registry records of primary invasive breast cancer diagnosed in 2010-2015 were linked to electronic health records in the Louisiana Public Health Institute's Research Action for Health Network. Controls were selected from Research Action for Health Network and matched to cases by age and race. Conditional logistic regression was used to identify metabolic risk factors. Data analysis was conducted in 2020‒2021.

RESULTS

There was a significant association between diabetes and breast cancer for Luminal A, Triple-Negative Breast Cancer, and human epidermal growth factor 2‒positive subtypes. In multiple logistic regression, including both obesity status and diabetes as independent risk factors, Luminal A breast cancer was also associated with overweight status. Diabetes was associated with increased risk for Luminal A and Triple-Negative Breast Cancer in subgroup analyses, including women aged ≥50 years, Black women, and White women.

CONCLUSIONS

Although research has identified obesity and diabetes as risk factors for breast cancer, these results underscore that comorbid risk is complex and may differ by molecular subtype. There was a significant association between diabetes and the incidence of Luminal A, Triple-Negative Breast Cancer, and human epidermal growth factor 2‒positive breast cancer in Louisiana.

Urinary Concentrations of Triclosan, Bisphenol A, and Brominated Flame Retardants and the Association of Triclosan with Demographic Characteristics and Body Fatness among Women with Newly Diagnosed Breast Cancer

Background: Triclosan, bisphenol A (BPA), and brominated flame retardants are environmental estrogenic endocrine-disrupting compounds that may influence the prognosis of breast cancer. We examined the urinary concentrations of these compounds and their associations with demographic characteristics and body fatness in a population of women with newly diagnosed breast cancer. Methods: Overnight urine collection and anthropometric measures were obtained from 302 participants. Triclosan, BPA, tetrabromobisphenol A (TBBPA), and tetrabromobenzoic acid (TBBA) concentrations were determined using ultra-performance liquid chromatography−tandem mass spectrometry. Regression analyses were conducted to examine associations of urinary compound concentration with age, menopause, race, ethnicity, educational level, estrogen receptor status, body size, and body composition. Results: Triclosan, BPA, and TBBA were detected in urine samples from 98.3%, 6.0%, and 0.3% of patients, respectively; TBBPA was undetectable. Among patients with quantifiable values, the geometric mean concentrations were 20.74 µg/L (27.04 µg/g creatinine) for triclosan and 0.82 µg/L (1.08 µg/g creatinine) for BPA. Body mass index ≥ 30 vs. <25 kg/m2 was associated with lower creatinine-corrected urinary concentrations of triclosan (−40.00, 95% confidence interval [CI] = −77.19 to −2.81; p = 0.0351). The observed association was predominantly in postmenopausal women (−66.57; 95% CI: −109.18% to −23.96%). Consistent results were found for associations between triclosan levels and fat mass variables. Conclusion: In this study population, women with newly diagnosed breast cancer had triclosan exposure. Assessments of the implications of urinary concentrations of triclosan for women should consider body fatness and menopausal status.

Greater Body Fatness Is Associated With Higher Protein Expression of LEPR in Breast Tumor Tissues: A Cross-Sectional Analysis in the Women's Circle of Health Study

BACKGROUND

The mechanisms underlying the association of overall and central body fatness with poorer breast cancer outcomes remain unclear; altered gene and/or protein expression of the adipokines and their receptors in breast tumors might play a role.

METHODS

In a sample of Black and White women with primary invasive breast cancer, we investigated associations of body mass index (BMI), waist circumference, hip circumference, waist-to-hip ratio (WHR), fat mass index (FMI), and percent body fat with protein expression (log-transformed, n = 722) and gene expression (log2-transformed, n = 148) of leptin (LEP), leptin receptor (LEPR), adiponectin (ADIPOQ), and adiponectin receptors 1 and 2 (ADIPOR1, ADIPOR2). Multivariable linear models, adjusting for race, menopausal status, and estrogen receptor status, were used to assess these associations, with Bonferroni correction for multiple comparisons.

RESULTS

In multivariable models, we found that increasing BMI (β = 0.0529, 95% CI: 0.0151, 0.0906) and FMI (β = 0.0832, 95% CI: 0.0268, 0.1397) were associated with higher LEP gene expression, corresponding to 34.5% and 38.3% increases in LEP gene expression for a standard deviation (SD) increase in BMI and FMI, respectively. Increasing BMI (β = 0.0028, 95% CI: 0.0011, 0.0045), waist circumference (β = 0.0013, 95% CI: 0.0005, 0.0022), hip circumference (β = 0.0015, 95% CI: 0.0007, 0.0024), and FMI (β = 0.0041, 95% CI: 0.0015, 0.0067) were associated with higher LEPR protein expression. These associations equate to 16.8%, 17.6%, 17.7%, 17.2% increases in LEPR protein expression for a 1-SD increase in BMI, waist circumference, hip circumference, and FMI, respectively. Further, these associations were stronger among White and postmenopausal women and ER+ cases; formal tests of interaction yielded evidence of effect modification by race. No associations of body fatness with LEP protein expression, LEPR gene expression, or protein or gene expression of ADIPOQ, ADIPOR1, and ADIPOR2 were found.

CONCLUSIONS

These findings support an association of increased body fatness - beyond overall body size measured using BMI - with higher LEP gene expression and higher LEPR protein expression in breast tumor tissues. Clarifying the impact of adiposity-related adipokine and adipokine receptor expression in breast tumors on long-term breast cancer outcomes is a critical next step.

Associations of hair dye and relaxer use with breast tumor clinicopathologic features: Findings from the Women's circle of Health Study

BACKGROUND

Building upon our earlier findings of significant associations between hair dye and relaxer use with increased breast cancer risk, we evaluated associations of select characteristics of use with breast tumor clinicopathology.

METHODS

Using multivariable-adjusted models we examined the associations of interest in a case-only study of 2998 women with breast cancer, overall and stratified by race and estrogen receptor (ER) status, addressing multiple comparisons using Bonferroni correction.

RESULTS

Compared to salon application of permanent hair dye, home kit and combination application (both salon and home kit application) were associated with increased odds of poorly differentiated tumors in the overall sample. This association was consistent among Black (home kit: OR 2.22, 95 % CI: 1.21-5.00; combination: OR 2.46, 95 % CI: 1.21-5.00), but not White women, and among ER+ (home kit: OR 1.47, 95 % CI: 0.82-2.63; combination: OR 2.98, 95 % CI: 1.62-5.49) but not ER-cases. Combination application of relaxers was associated with increased odds of tumors >2.0 cm vs. <1.0 cm (OR = 1.82, 95 % CI: 1.23-2.69). Longer duration and earlier use of relaxers and combination application of permanent hair dyes and relaxers were associated with breast tumor features including higher tumor grade and larger tumor size, which often denote more aggressive phenotypes, although the findings did not maintain significance with Bonferroni correction.

CONCLUSIONS

These novel data support reported associations between hair dye and relaxer use with breast cancer, showing for the first time, associations with breast tumor clinicopathologic features. Improved hair product exposure measurement is essential for fully understanding the impact of these environmental exposure with breast cancer and to guide risk reduction strategies in the future.

Interface between obesity with dysfunctional metabolism and inflammation, and the triple-negative breast cancer in African American women

Obesity has dramatically increased over the past fifty years. In the last decade, it has been noted that augmented body mass, metabolic abnormalities, and the relevant “obese” tumor microenvironment (TME) are connected with signaling molecular networks, which in turn, may contribute to aggressive tumor biology in some patients with breast malignancies. This article presents the associations between obesity, metabolic derangements, inflammatory processes in the adipose tissue or TME, and aggressive behavior of triple-negative breast cancer (TNBC) in African American (AA) women. It also describes some abnormal molecular signaling patterns in the “obese” TME with relevance to TNBC biology. Ethnic disparities in TNBC can be due to a variety of biological features (e.g., genetic mutations and tumor heterogeneity), comorbidities (e.g., cardio-metabolic diseases, including diabetes mellitus), and reproductive factors (e.g., multiparty or short breastfeeding period). Such a constellation of biological variables potentially leads to the association between obesity, metabolic derangements, inflammatory processes in the adipose tissue or TME, and aggressive behavior of TNBC in AA women. Since the TNBC and its TME can display very aggressive behavior, it is crucial that the afflicted AA women make efforts to maintain healthy body weight, “flexible” metabolism, and a well-functioning immune system. Further studies are merited to explore the multi-disciplinary factors that can affect TNBC prevention, management, and outcomes to optimize treatment strategies and survival among AA women.

Feasibility and potential efficacy of commercial mHealth/eHealth tools for weight loss in African American breast cancer survivors: pilot randomized controlled trial

Weight management after breast cancer (BC) treatment in African American (AA) women is crucial to reduce comorbid conditions and health disparities. We examined feasibility and potential efficacy of commercial eHealth/mHealth tools for weight management in AA BC survivors in New Jersey. Participants (N = 35) were randomized to an intervention (SparkPeople) plus activity tracker, Fitbit Charge (n = 18), or wait-list active control group (Fitbit only, n = 17). Anthropometric, behavioral, and quality of life (QOL) outcomes were collected at baseline, 3, 6, and 12 months. Differences in outcomes were assessed using intent-to-treat analysis. Retention was 97.1%. Both groups lost weight, with no significant differences between groups. At month 6, mean weight change was: intervention: -1.71 kg (SD 2.33; p = .006), 33.3% lost ≥3% of baseline weight; control: -2.54 kg (SD 4.00, p = .002), 23.5% lost ≥3% weight. Intervention participants achieved significant improvements in waist circumference (-3.56 cm, SD 4.70, p = .005), QOL (p = .030), and use of strategies for healthy eating (p = .025) and decreasing calories (p < .001). Number of days logged food per week was associated with decreases in waist circumference at 6 months (β -0.79, 95% CI, -1.49, -0.09, p = .030) and 12 months (β -2.16, 95% CI, -4.17, -0.15, p = .038). Weight loss was maintained at 12 months. This is the first study to demonstrate potential efficacy of commercial eHealth/mHealth tools for weight loss in AA BC survivors, without additional counseling from the research team. If effective, they may be convenient weight loss tools that can be easily and widely disseminated. Clinical Trials registration: ClinicalTrials.gov NCT02699983.

Patterns of Fitbit Use and Activity Levels Among African American Breast Cancer Survivors During an eHealth Weight Loss Randomized Controlled Trial

PURPOSE

This study examined adherence with a physical activity tracker and patterns of activity among different subgroups of African American/Black breast cancer survivors (AABCS).

DESIGN

Secondary analysis of weight loss trial that used an activity tracker (FitBit) with or without a commercial eHealth program (SparkPeople) over 12 months.

SETTING AND SUBJECTS

AABCS (N = 44) in New Jersey.

MEASURES AND ANALYSIS

Adherence with tracker use, steps per day, and active minutes per week were compared by demographic and clinical characteristics using nonparametric statistics.

RESULTS

Median adherence was over 6 days per week throughout the 12-months. Adherence was significantly correlated with steps and active minutes (p < 0.015). Groups with lower adherence included: those with 5 or more conditions (p = 0.039), had higher number of household members (p = 0.008), and younger than 60 years (p = 0.044). Median number of steps per day remained consistently around 7000 throughout 12 months. Factors associated with lower activity included: age > 60; retirement; higher number of household members, comorbidity, or baseline BMI; and those in the SparkPeople + Fitbit group. Self-monitoring, goal setting, and self-efficacy were significantly correlated with activity levels (p < 0.05).

CONCLUSION

Use of a physical activity tracker may help increase activity levels in AABCS. Certain subgroups, e.g. those older than age 60 years, retired, with BMI over 40, higher number of comorbidities or more household members, may require additional interventions.

Body fatness and breast cancer risk in relation to phosphorylated mTOR expression in a sample of predominately Black women

BACKGROUND

The mechanistic target of rapamycin (mTOR) pathway promoted by positive energy imbalance and insulin-like growth factors can be a mechanism by which obesity influences breast cancer risk. We evaluated the associations of body fatness with the risk of breast cancer varied with phosphorylated (p)-mTOR protein expression, an indication of the pathway activation.

METHODS

Women with newly diagnosed breast cancer (n = 715; 574 [80%] Black and 141 [20%] White) and non-cancer controls (n = 1983; 1280 [64%] Black and 713 [36%] White) were selected from the Women's Circle of Health Study. Surgical tumor samples among the cases were immunostained for p-mTOR (Ser2448) and classified as p-mTOR-overexpressed, if the expression level ≥ 75th percentile, or p-mTOR-negative/low otherwise. Anthropometrics were measured by trained staff, and body composition was determined by bioelectrical impedance analysis. Odds ratios (ORs) of p-mTOR-overexpressed tumors and p-mTOR-negative/low tumors compared to controls were estimated using polytomous logistic regression. The differences in the associations by the p-mTOR expression status were assessed by tests for heterogeneity.

RESULTS

Cases with p-mTOR-overexpressed tumors, but not cases with p-mTOR-negative/low tumors, compared to controls were more likely to have higher body mass index (BMI), percent body fat, and fat mass index (P-heterogeneity < 0.05), although the OR estimates were not significant. For the measurement of central adiposity, cases with p-mTOR overexpressed tumors had a higher odds of being at the Q3 (OR = 2.52, 95% CI = 1.46 to 4.34) and Q4 (OR = 1.99, 95% CI = 1.12 to 3.50) of waist circumference (WC) compared to controls. Similarly, cases with p-mTOR overexpressed tumors had a higher odds of being at the Q3 (OR = 1.82, 95% CI = 1.11 to 2.98) and Q4 (OR = 1.81, 95% CI = 1.11 to 2.98) of WHR compared to controls. These associations of WC and waist-to-hip ratio (WHR) did not differ by tumor p-mTOR status (P-heterogeneity = 0.27 and 0.48, respectively).

CONCLUSIONS

Our findings suggest that in this population composed of predominately Black women, body fatness is associated with breast cancer differently for p-mTOR overexpression and p-mTOR negative/low expression. Whether mTOR plays a role in the obesity and breast cancer association warrants confirmation by prospective studies.

Association of Body Mass Index, Central Obesity, and Body Composition With Mortality Among Black Breast Cancer Survivors

IMPORTANCE

Obesity disproportionately affects Black women, who also have a higher risk of death after a breast cancer diagnosis compared with women of other racial/ethnic groups. However, few studies have evaluated the association of measures of adiposity with mortality among Black breast cancer survivors.

OBJECTIVE

To assess the association of measures of adiposity with survival after a breast cancer diagnosis among Black women.

DESIGN, SETTING, AND PARTICIPANTS

This prospective population-based cohort study comprised 1891 women with stage 0 to IV breast cancer who self-identified as African American or Black and were ages 20 to 75 years. The New Jersey State Cancer Registry was used to identify women living in 10 counties in New Jersey who were recruited from March 1, 2006, to February 29, 2020, and followed up until September 2, 2020.

EXPOSURES

Measures of adiposity, including body mass index, body fat distribution (waist circumference and waist-to-hip ratio), and body composition (percent body fat and fat mass index), were collected during in-person interviews at approximately 10 months after breast cancer diagnosis.

MAIN OUTCOMES AND MEASURES

All-cause and breast cancer-specific mortality.

RESULTS

Among 1891 women, the mean (SD) age at breast cancer diagnosis was 54.5 (10.8) years. During a median follow-up of 5.9 years (range, 0.5-14.8 years), 286 deaths were identified; of those, 175 deaths (61.2%) were associated with breast cancer. A total of 1060 women (56.1%) had obesity, and 1291 women (68.3%) had central obesity. Higher adiposity, particularly higher waist-to-hip ratio, was associated with worse survival. Women in the highest quartile of waist-to-hip ratio had a 61% increased risk of dying from any cause (hazard ratio [HR], 1.61; 95% CI, 1.12-2.33) and a 68% increased risk of breast cancer death (HR, 1.68; 95% CI, 1.04-2.71) compared with women in the lowest quartile. The risks of all-cause and breast cancer-specific death were similarly high among women in the highest quartile for waist circumference (HR, 1.74 [95% CI, 1.26-2.41] and 1.64 [95% CI, 1.08-2.48], respectively), percent body fat (HR, 1.53 [95% CI, 1.09-2.15] and 1.81 [95% CI, 1.17-2.80]), and fat mass index (HR, 1.57 [95% CI, 1.11-2.22] and 1.74 [95% CI, 1.10-2.75]); however, the risk was less substantial for body mass index (HR, 1.26 [95% CI, 0.89-1.79] and 1.33 [95% CI, 0.84-2.10]). In analyses stratified by estrogen receptor status, menopausal status, and age, a higher waist-to-hip ratio was associated with a higher risk of all-cause death among women who had estrogen receptor-negative tumors (HR, 2.24; 95% CI, 1.14-4.41), women who were postmenopausal (HR, 2.15; 95% CI, 1.28-3.61), and women who were 60 years or older at diagnosis (HR per 0.10-U increase, 1.76; 95% CI, 1.37-2.26).

CONCLUSIONS AND RELEVANCE

In this population-based cohort study, central obesity and higher adiposity were associated with higher all-cause and breast cancer-specific mortality among Black breast cancer survivors. Simple measures of body fat distribution and body composition were found to be useful tools for identifying Black women with a higher risk of death after a breast cancer diagnosis.

Harnessing Nutrition and Physical Activity for Breast Cancer Prevention and Control to Reduce Racial/Ethnic Cancer Health Disparities

There are well-known racial/ethnic disparities in the prevalence of obesity and physical inactivity, as well as breast cancer risk and survival. However, most of the current scientific evidence that serves as a foundation for nutrition and physical activity guidelines is based on studies conducted in predominantly non-Hispanic White populations. Similarly, exercise, diet, or lifestyle intervention trials for breast cancer prevention and survivorship are scarce in racial/ethnic minority populations. We review the current evidence for racial/ethnic disparities in obesity and breast cancer risk and survival (we are focusing on obesity, because this is considered an ASCO priority, and studies conducted in the United States), discuss the evolution of nutrition/physical activity guidelines for cancer prevention and control, and provide an overview of lifestyle interventions, including barriers and facilitators in implementation and dissemination science among minority populations underrepresented in research. There is a critical need to include racially/ethnically diverse populations in cancer prevention and control research or to specifically target minority populations in which disparities are known to exist to achieve much needed health equity.

Patterns of chronic disease management and health outcomes in a population-based cohort of Black women with breast cancer

PURPOSE

Diabetes and hypertension are two common comorbidities that affect breast cancer patients, particularly Black women. Disruption of chronic disease management during cancer treatment has been speculated. Therefore, this study examined the implementation of clinical practice guidelines and health outcomes for these comorbidities before and during cancer treatment.

METHODS

We used a population-based, prospective cohort of Black women diagnosed with breast cancer (2012-2016) in New Jersey (n = 563). Chronic disease management for diabetes and hypertension was examined 12 months before and after breast cancer diagnosis and compared using McNemar's test for matched paired and paired t tests.

RESULTS

Among this cohort, 18.1% had a co-diagnosis of diabetes and 47.2% had a co-diagnosis of hypertension. Implementation of clinical practice guidelines and health outcomes that differed in the 12 months before and after cancer diagnosis included lipid screening (64.5% before versus 50.0% after diagnosis; p = 0.004), glucose screening (72.7% versus 90.7%; p < 0.001), and blood pressure control < 140/90 mmHg (57.6% versus 71.5%; p = 0.004) among patients with hypertension-only. For patients with diabetes, eye and foot care were low (< 35%) and optimal HbA1c < 8.0% was achieved for less than 50% of patients in both time periods.

CONCLUSION

Chronic disease management continued during cancer treatment; however, eye and foot exams for patients with diabetes and lipid screening for patients with hypertension-only were inadequate. Given that comorbidities may account for half of the Black-White breast cancer survival disparity, strategies are needed to improve chronic disease management during cancer, especially for Black women who bear a disproportionate burden of chronic diseases.

Visual cues of the built environment and perceived stress among a cohort of black breast cancer survivors

We investigated relationships between independently observed, visual cues of residential environments and subsequent participant-reported stress within a population-based cohort of Black breast cancer survivors (n = 476). Greater visual cues of engagement - presence of team sports, yard decorations, outdoor seating - (compared to less engagement) was marginally associated with lower perceived stress in univariate models, but attenuated towards null with adjustment for socio-demographic, behavioral, and health-related covariates. Similarly, physical disorder and perceived stress were not associated in adjusted models. Relationships between observed built environment characteristics and perceived stress might be influenced by socioeconomic and health behavior factors, which longitudinal studies should investigate.

Prevalence, risk factors, and trajectories of sleep disturbance in a cohort of African-American breast cancer survivors

PURPOSE

Sleep disturbance may be an overlooked modifiable risk factor for health disparities among African-American breast cancer survivors (AABCS). This study aimed to identify the prevalence of and risk factors for sleep disturbance in a cohort of AABCS.

METHODS

The study was conducted among participants in the Women's Circle of Health Follow-up Study, a longitudinal study of breast cancer in 10 counties in New Jersey. Cases were identified shortly after diagnosis by the New Jersey State Cancer Registry. Self-reported sleep disturbance (Pittsburgh Sleep Quality Index) and other factors (e.g., socioeconomic status, menopausal status) were assessed at pre-diagnosis (n = 637), 10 months post-diagnosis (n = 261), and 24 months post-diagnosis (n = 632). Clinical data were obtained via medical record abstraction, and height and weight were measured by study staff.

RESULTS

Most AABCS (57%) reported clinically significant sleep disturbance before diagnosis, and this rate remained largely unchanged at 10 months (53%) and 24 months post-diagnosis (61%). Average sleep disturbance scores indicated clinically significant disturbance at all three assessments (M range = 6.67-7.57). Most reported sleeping fewer than the recommended 7 hours per night at each assessment (range 57-65%). Risk factors for sleep disturbance were identified at each assessment, including pre-diagnosis (less education), 10 months post-diagnosis (lack of insurance, treatment with chemotherapy), and 24 months post-diagnosis (younger age, less education, lower income, obesity, and lymphedema). Treatment with endocrine therapy was a protective factor at 10 months post-diagnosis.

CONCLUSION

Most AABCS report clinically significant sleep disturbance from before diagnosis through 24 months post-diagnosis. These rates appear indicate AABCS experience significant sleep-related disparities.

Body fatness and mTOR pathway activation of breast cancer in the Women's Circle of Health Study

Energy imbalance has an important role in breast cancer prognosis. Hyperactive mechanistic Target of Rapamycin (mTOR) pathway is associated with breast tumor growth, but the extent to which body fatness is associated with mTOR pathway activities in breast cancer is unclear. We performed immunostaining for mTOR, phosphorylated (p)-mTOR, p-AKT, and p-p70S6K in tumor tissue from 590 women (464 African Americans/Blacks and 126 Whites) with newly diagnosed invasive breast cancer in the Women's Circle of Health Study. Anthropometric measures were taken by study staff, and body composition was measured by bioelectrical impedance analysis. Linear regressions were used to estimate percent differences in protein expression between categories of body mass index (BMI), waist circumference, waist/hip ratio, fat mass, fat mass index, and percent body fat. We observed that BMI ≥ 35.0 vs. <25 kg/m2 was associated with 108.3% (95% CI = 16.9%-270.9%) and 101.8% (95% CI = 17.0%-248.8%) higher expression in p-mTOR and normalized p-mTOR, i.e., p-mTOR/mTOR, respectively. Quartiles 4 vs. 1 of waist/hip ratio was associated with 41.8% (95% CI = 5.81%-89.9%) higher mTOR expression. Similar associations were observed for the body fat measurements, particularly in patients with estrogen receptor-negative (ER-) tumors, but not in those with ER+ tumors, although the differences in associations were not significant. This tumor-based study found positive associations between body fatness and mTOR pathway activation, evident by a p-mTOR expression, in breast cancer. Our findings suggest that mTOR inhibition can be a treatment strategy to prevent the recurrence of these tumors in obese individuals.

Pre-diagnostic allostatic load and health-related quality of life in a cohort of Black breast cancer survivors

PURPOSE

To determine the association of pre-diagnostic allostatic load (AL) with health-related quality of life (HRQOL) among Black women with breast cancer.

METHODS

In a sample of 409 Black women with non-metastatic breast cancer enrolled in the Women's Circle of Health Follow-Up Study (WCHFS), two pre-diagnostic AL measures were estimated using medical records data from up to 12 months prior to breast cancer diagnosis: AL-lipid/metabolic profile-based measure and AL-inflammatory profile-based measure. HRQOL was assessed approximately 24 months post diagnosis, using the Functional Assessment of Cancer Therapy-Breast Cancer (FACT-B) instrument, including 5 subscale scores [presented by physical well-being (PWB), social & family well-being (SFWB), emotional well-being (EWB), functional well-being (FWB), and breast cancer-specific scale (BCS)] and 3 derived total scores [presented by trial outcome index (TOI), Functional Assessment of Cancer Therapy-General (FACT-G) and FACT-B]. We used multivariable logistic regression models, using dichotomized AL scores (lower AL: 0-3 points, higher AL: 4-8 points), to assess the associations between the two pre-diagnostic AL measures and HRQOL.

RESULTS

Higher pre-diagnostic AL was associated with poorer FWB and lower FACT-G, but these associations were statistically significant for the AL-inflammatory profile-based measure (FWB: OR 1.63, 95% CI 1.04, 2.56; FACT-G: OR 1.62, 95% CI 1.04, 2.54), but not the AL-lipid/metabolic profile-based measure (FWB: OR 1.45, 95% CI 0.81, 2.59; FACT-G: OR 1.33, 95% CI 0.75, 2.37).

CONCLUSION

These findings suggest that higher AL, particularly when measured using the inflammatory profile-based measure, was associated with poorer HRQOL, namely FWB and FACT-G, among Black breast cancer survivors.

The Association between Obesity and Premenopausal Breast Cancer According to Intrinsic Subtypes - a Systematic Review

Introduction Obesity is a well-established risk factor for postmenopausal hormone-receptor positive breast cancer. The relationship between premenopausal breast cancer intrinsic subtypes and obesity is not completely elucidated; therefore, this systematic review was conducted to give an overview about the existing evidence. Methods This review followed the PRISMA Statement for Systematic Reviews and Meta-analyses. Full electronic search was conducted in PubMed and Orbis for articles published in English between January 2008 and June 2018. The literature search was performed in June 2018 using search strings that combined the Medical Subject Headings (MeSH terms) keywords and/or text words in any field were used: "body mass index" (BMI) OR obesity OR overweight AND premenopausal breast cancer. Results 391 articles were found to be eligible, of which ultimately 21 were included comprising a total of 55 580 breast cancer patients. 45% were case-control studies, 35% were single cohort studies, 15% were cohort studies, two were cross-sectional studies, one was a multicenter-study and one was a pooled analysis. The evidence shows a tendency for an increased risk for the more aggressive triple negative breast cancer subtype in obese premenopausal women and a decreased risk for less aggressive tumor subtypes such as the luminal A subtype. The evidence is limited by small sample sizes for triple negative and HER2-positive subtypes in severely obese patients. Conclusion Higher BMI might influence aggressive tumor characteristics among premenopausal women and has divergent impacts on the risk of different breast cancer subtypes. Further research is needed to confirm these results and to evaluate potential pathophysiologic mechanisms for the relationship between obesity and aggressive premenopausal breast cancer subtypes.

Immunohistochemical analysis of adipokine and adipokine receptor expression in the breast tumor microenvironment: associations of lower leptin receptor expression with estrogen receptor-negative status and triple-negative subtype

BACKGROUND

The molecular mechanisms underlying the association between increased adiposity and aggressive breast cancer phenotypes remain unclear, but likely involve the adipokines, leptin (LEP) and adiponectin (ADIPOQ), and their receptors (LEPR, ADIPOR1, ADIPOR2).

METHODS

We used immunohistochemistry (IHC) to assess LEP, LEPR, ADIPOQ, ADIPOR1, and ADIPOR2 expression in breast tumor tissue microarrays among a sample of 720 women recently diagnosed with breast cancer (540 of whom self-identified as Black). We scored IHC expression quantitatively, using digital pathology analysis. We abstracted data on tumor grade, tumor size, tumor stage, lymph node status, Ki67, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) from pathology records, and used ER, PR, and HER2 expression data to classify breast cancer subtype. We used multivariable mixed effects models to estimate associations of IHC expression with tumor clinicopathology, in the overall sample and separately among Blacks.

RESULTS

Larger proportions of Black than White women were overweight or obese and had more aggressive tumor features. Older age, Black race, postmenopausal status, and higher body mass index were associated with higher LEPR IHC expression. In multivariable models, lower LEPR IHC expression was associated with ER-negative status and triple-negative subtype (P < 0.0001) in the overall sample and among Black women only. LEP, ADIPOQ, ADIPOR1, and ADIPOR2 IHC expression were not significantly associated with breast tumor clinicopathology.

CONCLUSIONS

Lower LEPR IHC expression within the breast tumor microenvironment might contribute mechanistically to inter-individual variation in aggressive breast cancer clinicopathology, particularly ER-negative status and triple-negative subtype.

The Women's Circle of Health Follow-Up Study: a population-based longitudinal study of Black breast cancer survivors in New Jersey

PURPOSE

The Women's Circle of Health Follow-Up Study is an ongoing longitudinal study of African American/Black breast cancer survivors in New Jersey, specifically designed to evaluate the impact of obesity and related comorbidities on breast cancer survival and health-related quality-of-life in this understudied population. Here, we describe our recruitment and data collection methods and compare characteristics of the overall cohort and the subcohort with follow-up data.

METHODS

Newly diagnosed breast cancer cases have been recruited into the study since 2006. Pre-diagnosis data on relevant factors and a saliva sample are collected during an in-person interview within 12 months from diagnosis. In 2013, we began active follow up by recontacting participants annually, including two home visits at approximately 2 and 3 years post-diagnosis, during which blood samples are collected. Mortality outcomes (all-cause and breast cancer-specific mortality) are ascertained through linkage with New Jersey State Cancer Registry files. We expect to assemble a cohort of over 2000 Black breast cancer survivors with at least 800 of them having detailed post-diagnosis data.

RESULTS

Distribution of sociodemographic characteristics, body mass index, comorbidities, clinicopathologic characteristics, and treatment modalities were very similar between those in the full cohort and the subset with follow-up data and blood samples. Obesity (> 50%), hypertension (> 58%), and diabetes (22%) were common in this population.

CONCLUSIONS AND IMPLICATIONS FOR CANCER SURVIVORS

This ongoing longitudinal study represents a unique resource to better understand breast cancer outcomes, patient-reported symptoms, and health-related quality of life among Black breast cancer survivors.

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.

Prediagnostic Allostatic Load as a Predictor of Poorly Differentiated and Larger Sized Breast Cancers among Black Women in the Women's Circle of Health Follow-Up Study

BACKGROUND

Few studies have empirically tested the association of allostatic load (AL) with breast cancer clinicopathology. The aim of this study was to examine the association of AL, measured using relevant biomarkers recorded in medical records before breast cancer diagnosis, with unfavorable tumor clinicopathologic features among Black women.

METHODS

In a sample of 409 Black women with nonmetastatic breast cancer who are enrolled in the Women's Circle of Health Follow-Up Study, we estimated prediagnostic AL using two measures: AL measure 1 [lipid profile-based-assessed by systolic and diastolic blood pressure (SBP, DBP), high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides, and glucose levels; waist circumference; and use of diabetes, hypertension, or hypercholesterolemia medication] and AL measure 2 (inflammatory index-based-assessed by SBP, DBP, glucose, and albumin levels; estimated glomerular filtration rate; body mass index; waist circumference; and use of medications previously described). We used Cohen's statistic to assess agreement between the two AL measures and multivariable logistic models to assess the associations of interest.

RESULTS

AL measures 1 and 2 moderately agreed (κ = 0.504). Higher prediagnostic AL predicted higher grade (poorly differentiated vs. well/moderately differentiated) using AL measure 1 [OR = 2.16; 95% confidence interval (CI), 1.18-3.94] and AL measure 2 (OR = 1.60; 95% CI, 1.02-2.51), and larger tumor size (≥2 cm vs. <2 cm; OR = 1.58; 95% CI, 1.01-2.46) using AL measure 2 only.

CONCLUSIONS

Elevated prediagnostic AL might contribute to more unfavorable breast cancer clinicopathology.

IMPACT

Addressing elevated prediagnostic levels of AL has potentially important clinical implications.

The Many Faces of Obesity and Its Influence on Breast Cancer Risk

Obesity is associated with increased risk of breast and other cancers. However, the complexity of the underlying mechanisms, together with the interplay of diet and physical activity—contributing to energy balance—and the role of adipose tissue, pose challenges to our understanding of the basis of this increased risk. Epidemiologic studies have documented a higher obesity prevalence in US black women compared to white women. Elucidation of the contribution of potential biological differences among racially distinct groups to their differences in breast cancer (BC) risk and mortality have been topics of considerable interest in recent years. The racial and ethnic variation in body fat distribution may account for at least part of the differences in breast cancer rates in these populations. Yet, while black women exhibit higher rates of obesity compared to white women, this does not translate directly into higher rates of BC. In fact, overall, BC in black women occurs with a lower incidence than BC in white women. Obesity is a known risk factor for postmenopausal breast cancer, and growing evidence suggests that abdominal obesity, also known as central obesity, may increase risk for triple negative breast cancer, which is more common in premenopausal women. The positive association of postmenopausal BC risk and specifically estrogen receptor (ER)-positive BC, is presumably due largely to accumulation of estrogen in the adipose tissue of the breast and other tissues. Of the two main types of adipose tissue—subcutaneous and visceral—visceral adipocytes are more active metabolically. Such adipose tissue harbors multiple molecular entities that promote carcinogenesis: endocrine molecules/hormones, immunologic factors, inflammatory cytokines, metabolic alterations, and other components of the microenvironment. Expression of these culpable entities is largely regulated by epigenetic mechanisms. The interrelationship between these entities and drivers of epigenetic alteration are critical to the regulation of pathways connecting obesity and cancer risk. Initiatives to counteract the carcinogenic effects of obesity have primarily involved modulation of energy balance by diet. However, targeting of specific molecular abnormalities characterizing adiposity offers an alternative approach to preventing cancer. Our goal in this review is to first discuss the major mechanisms contributing to the obesity-breast cancer link. We will also consider race, specifically black/white differences, as they relate to the association of obesity with breast cancer risk. Then we will enumerate strategies targeting these mechanisms to reduce BC risk, in large part by way of dietary interventions with potential to mitigate the cancer-promoting components of adiposity.

Factors Associated with Initial Mode of Breast Cancer Detection among Black Women in the Women's Circle of Health Study

Mammogram-detected breast cancers have a better prognosis than those identified through clinical breast exam (CBE) or through self-detection, primarily because tumors detected by mammography are more likely to be smaller and do not involve regional nodes. In a sample of 1,322 Black women, aged 40-75 years, diagnosed with breast cancer between 2002 and 2016, we evaluated factors associated with CBE and self-detection versus screening mammogram as the initial mode of breast cancer detection, using multivariable logistic regression models. Compared with screening mammogram, history of routine screening mammogram (OR 0.20, 95% CI: 0.07, 0.54) and performance of breast self-examination (BSE) (OR 0.31, 95% CI: 0.13, 0.74) before diagnosis were associated with lower odds of CBE as the initial mode of detection, while performance of CBEs before diagnosis (OR 11.04, 95% CI: 2.24, 54.55) was positively associated. Lower body mass index (<25.0 kg/m2 vs. ≥35.0 kg/m2: OR 2.46, 95% CI: 1.52, 3.98), performance of BSEs before diagnosis (less than once per month: OR 4.08, 95% CI: 2.45, 6.78; at least monthly: OR 4.99, 95% CI: 3.13, 7.97), and larger tumor size (1.0-2.0 cm vs. <1.0 cm: OR 2.92, 95% CI: 1.84, 4.64; >2.0 cm vs. <1.0 cm: OR 6.41, 95% CI: 3.30, 12.46) were associated with increased odds of self-detection relative to screening mammogram. The odds of CBE and self-detection as initial modes of breast cancer detection among Black women are independently associated with breast care and breast cancer screening services before diagnosis and with larger tumors at diagnosis.

The Relationship between Anthropometric Indices and Breast Cancer in Central Iran

Background: Anthropometric indices have a debatable relationship with breast cancer (BC) among different ethnicity. In the current study, we have evaluated the relationship between anthropometric indices and BC in Iranian participants. Methods: Between 2012 and 2014, a total of 7,805 women were enrolled from different mammography centers in Isfahan province, Iran. For each participant, a detailed questionnaire was filled out and anthropometric indices were measured by trained technicians. We used logistic regression models to estimate odds ratios (OR) and 95% confidence interval (CI) for BC risk associated with anthropometry measurements, stratified on menopausal status. Results: In the postmenopausal group, weight ≥68 kg compared to weight <61.75 kg was associated with decreased risk of BC (OR = 0.78; 95% CI: 0.63-0.97). Postmenopausal women with Waist-Hip Ratio (WHR) ≥ 0.85 compared to WHR < 0.77 were at increased risk of BC (OR = 1.36; 95% CI: 1.07-1.73). Both premenopausal and postmenopausal women had a decreased risk of BC with higher Obesity Index (OI) and Relative Weight. Conclusion: Ethnicity appears to play an important role in the discrepancies between results of different studies about the correlation of anthropometric features with BC.

Human ancestry indentification under resource constraints -- what can one chromosome tell us about human biogeographical ancestry?

BACKGROUND

While continental level ancestry is relatively simple using genomic information, distinguishing between individuals from closely associated sub-populations (e.g., from the same continent) is still a difficult challenge.

METHODS

We study the problem of predicting human biogeographical ancestry from genomic data under resource constraints. In particular, we focus on the case where the analysis is constrained to using single nucleotide polymorphisms (SNPs) from just one chromosome. We propose methods to construct such ancestry informative SNP panels using correlation-based and outlier-based methods.

RESULTS

We accessed the performance of the proposed SNP panels derived from just one chromosome, using data from the 1000 Genome Project, Phase 3. For continental-level ancestry classification, we achieved an overall classification rate of 96.75% using 206 single nucleotide polymorphisms (SNPs). For sub-population level ancestry prediction, we achieved an average pairwise binary classification rates as follows: subpopulations in Europe: 76.6% (58 SNPs); Africa: 87.02% (87 SNPs); East Asia: 73.30% (68 SNPs); South Asia: 81.14% (75 SNPs); America: 85.85% (68 SNPs).

CONCLUSION

Our results demonstrate that one single chromosome (in particular, Chromosome 1), if carefully analyzed, could hold enough information for accurate prediction of human biogeographical ancestry. This has significant implications in terms of the computational resources required for analysis of ancestry, and in the applications of such analyses, such as in studies of genetic diseases, forensics, and soft biometrics.

The Obesity and the Risk of Breast Cancer among Pre and Postmenopausal Women

Background: Breast cancer is the most common cancer among women worldwide and the obesity is one of the factors related to the risk of breast cancer mainly in postmenopausal women. This study investigated the association between obesity in pre- and postmenopausal women with the development of breast cancer and the expression of estrogen, progesterone, HeR-2 and triple-negative (TN) receptors. Methods: A case-control study was conducted on 100 patients with recently diagnosed breast cancer and 400 age-matched controls. The women were divided into pre- and post-menopausal groups. Results: The multivariate analysis showed that postmenopausal women with a BMI ≥ 30 kg/m2 at pre-diagnosis and at the most recent measurement were 1.50 (95% CI 1.06-2.13) and 1.56 (95% CI 1.11-2.21) times more likely to develop breast cancer, respectively. These women had a prevalence of obesity of 27.7% when considering pre-diagnosis BMI and 29.4% when analyzing the indicator of recent BMI. When only the cases regarding the presence of obesity with clinicopathological variables were analyzed, a total of 95.2% of the postmenopausal women with pre-diagnostic obesity according to BMI presented the positive estrogen receptor (ER) subtype. Conclusions: In Brazilian women, there is an association between obesity and the risk of breast cancer postmenopause; moreover, there is an association between the occurrence of the positive ER subtype in postmenopausal women and pre-diagnostic obesity according to BMI.

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.

Validity of self-reported weight, height, and body mass index among African American breast cancer survivors

PURPOSE

Self-reported weight, height, and body mass index (BMI) are commonly used in cancer epidemiology studies, but information on the validity of self-reports among cancer survivors is lacking. This study aimed to evaluate the validity of these self-reported measures among African American (AA) breast cancer survivors, known to have high obesity prevalence.

METHODS

We compared the self-reported and measured values among 243 participants from the Women's Circle of Health Follow-Up Study (WCHFS), a population-based longitudinal study of AA breast cancer survivors. Multivariable-adjusted linear regressions were used to identify factors associated with reporting errors. We also examined the associations of self-reported and measured BMI with obesity-related health outcomes using multivariable logistic regressions, with hypertension as an example, to evaluate the impact of misreporting.

RESULTS

We found that self-reported and measured values were highly correlated among all and when stratified by participants' characteristics (intraclass correlation coefficients ≥ 0.99, 0.84, and 0.96 for weight, height, and BMI, respectively). The agreement between BMI categories (normal, overweight and obese) based on self-reported and measured data was excellent (kappa = 0.81). Women who were older, never smoked, had higher grade tumors, or had greater BMI tended to have overestimated BMI calculated from self-reported weight and height. The BMI-hypertension association was similar using self-reported (OR per 5 kg/m2 increase 1.63; 95% CI 1.27-2.10) and measured BMI (1.58; 95% CI 1.23-2.03).

CONCLUSIONS

Self-reported weight, height, and BMI were reasonably accurate in the WCHFS.

IMPLICATIONS FOR CANCER SURVIVORS

Our study supports the use of these self-reported values among cancer survivors when direct measurements are not possible.

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.

Breast Cancer Risk From Modifiable and Non-Modifiable Risk Factors among Women in Southeast Asia: A Meta-Analysis

Objective:

The aim of this study was to determine breast cancer risk from modifiable and non-modifiable factors among women in Southeast Asia.

Methods:

This meta-analysis was performed on research articles on breast cancer risk factors in PubMed, ProQuest and EBSCO databases published between 1997 and October 2017. Pooled odds ratios (OR) are calculated using fixed and random-effect models. Data were processed using Review Manager 5.3 (RevMan 5.3).

Results:

From a total of 1,211 articles, 15 studies (1 cohort and 14 case control studies) met the criteria for systematic review. Meta-analysis results showed that of the known modifiable risk factors for breast cancer, parity (nulipara) had the highest odd ratio (OR = 1.85 [95% CI 1.47-2.32]) followed by body mass index (overweight) (OR = 1.61 [95% CI 1.43-1.80]) and use of oral contraceptives (OR = 1.27 [95% CI 1.07-1.51]). Of non-modifiable risk factors, family history of breast cancer had the highest odd ratio (OR = 2.53 [95% CI 1.25-5.09]), followed by age (≥ 40 years) (OR = 1.53 [95% CI 1.34-1.76]) and menopausal status (OR = 1.44 [95% CI 1.26-1.65]).

Conclusion:

This analysis confirmed associations between both modifiable risk factors (parity, body mass index and use of oral contraceptives) and non-modifiable risk factors (family history of breast cancer, age and menopausal status) with breast cancer.

Hair product use and breast cancer risk among African American and White women

Exposures to carcinogens in hair products have been explored as breast cancer risk factors, yielding equivocal findings. We examined hair product use (hair dyes, chemical relaxers and cholesterol or placenta-containing conditioners) among African American (AA) and White women, and explored associations with breast cancer. Multivariable-adjusted models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to describe the associations of interest among 2280 cases (1508 AA and 772 White) and 2005 controls (1290 AA and 715 White). Among controls, hair dye use was more common among Whites than AAs (58 versus 30%), while relaxer (88 versus 5%) and deep conditioner use (59 versus 6%) was more common among AAs. Among AAs, use of dark hair dye shades was associated with increased breast cancer risk (OR = 1.51, 95% CI: 1.20-1.90) and use of dark shades (OR = 1.72, 95% CI: 1.30-2.26) and higher frequency of use (OR = 1.36, 95% CI: 1.01-1.84) were associated with ER+ disease. Among Whites, relaxer use (OR = 1.74, 95% CI: 1.11-2.74) and dual use of relaxers and hair dyes (OR = 2.40, 95% CI: 1.35-4.27) was associated with breast cancer; use of dark hair dyes was associated with increased ER+ disease (OR = 1.54, 95% CI: 1.01-2.33), and relaxer use was associated with increased ER- disease (OR = 2.56, 95% CI: 1.06-6.16). These novel findings provide support a relationship between the use of some hair products and breast cancer. Further examinations of hair products as important exposures contributing to breast cancer carcinogenesis are necessary.

The use and interpretation of anthropometric measures in cancer epidemiology: A perspective from the world cancer research fund international continuous update project

Anthropometric measures relating to body size, weight and composition are increasingly being associated with cancer risk and progression. Whilst practical in epidemiologic research, where population-level associations with disease are revealed, it is important to be aware that such measures are imperfect markers of the internal physiological processes that are the actual correlates of cancer development. Body mass index (BMI), the most commonly used marker for adiposity, may mask differences between lean and adipose tissue, or fat distribution, which varies across individuals, ethnicities, and stage in the lifespan. Other measures, such as weight gain in adulthood, waist circumference and waist-to-hip ratio, contribute information on adipose tissue distribution and insulin sensitivity. Single anthropometric measures do not capture maturational events, including the presence of critical windows of susceptibility (i.e., age of menarche and menopause), which presents a challenge in epidemiologic work. Integration of experimental research on underlying dynamic genetic, hormonal, and other non-nutritional mechanisms is necessary for a confident conclusion of the overall evidence in cancer development and progression. This article discusses the challenges confronted in evaluating and interpreting the current evidence linking anthropometric factors and cancer risk as a basis for issuing recommendations for cancer prevention.

Differential Patterns of Risk Factors for Early-Onset Breast Cancer by ER Status in African American Women

BACKGROUND

Given the disproportionately high incidence of early-onset breast cancer and aggressive subtypes, such as estrogen receptor (ER)-negative tumors, in African American (AA) women, elucidation of risk factors for early onset of specific subtypes of breast cancer is needed.

METHODS

We evaluated associations of reproductive, anthropometric, and other factors with incidence of invasive breast cancer by age at onset (<45, ≥45) in 57,708 AA women in the prospective Black Women's Health Study. From 1995 to 2013, we identified 529 invasive breast cancers among women <45 years of age (151 ER^-, 219 ER⁺) and 1,534 among women ≥45 years (385 ER^-, 804 ER⁺). We used multivariable Cox proportional hazards regression to estimate hazard ratios (HRs) for associations by age and ER status.

RESULTS

Higher parity, older age at first birth, never having breastfed, and abdominal adiposity were associated with increased risk of early-onset ER^- breast cancer: HRs were 1.71 for ≥3 births versus one birth; 2.29 for first birth after age 25 versus <20 years; 0.61 for ever having breastfed versus never; and 1.64 for highest versus lowest tertile of waist-to-hip ratio. These factors were not associated with ER^- cancer in older women or with ER⁺ cancer regardless of age.

CONCLUSIONS

Differences in risk factors by ER subtype were observed for breast cancer diagnosed before the age of 45 years.

IMPACT

Etiological heterogeneity by tumor subtype in early-onset breast cancer, in combination with a higher prevalence of the risk factors in AA women, may explain, in part, racial disparities in breast cancer incidence. Cancer Epidemiol Biomarkers Prev; 26(2); 270-7. ©2016 AACR.

Genetic variants in the mTOR pathway and interaction with body size and weight gain on breast cancer risk in African-American and European American women

PURPOSE

Positive energy imbalance and growth factors linked to obesity promote the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (mTOR) pathway. As the obesity-breast cancer associations differ between European American (EA) and African-American (AA) women, we investigated genetic variants in the mTOR pathway and breast cancer risk in these two racial groups.

METHODS

We examined 400 single-nucleotide polymorphisms (SNPs) in 31 mTOR pathway genes in the Women's Circle of Health Study with 1263 incident breast cancers (645 EA, 618 AA) and 1382 controls (641 EA, 741 AA). Multivariable logistic regression was performed separately within racial groups. Effect modification was assessed for measured body size and weight gain since age 20.

RESULTS

In EA women, variants in FRAP1 rs12125777 (intron), PRR5L rs3740958 (synonymous coding), and CDKAL1 rs9368197 (intron) were associated with increased breast cancer risk, while variants in RPTOR rs9900506 (intron) were associated with decreased risk (nominal p-trend for functional and FRAP1 SNPs or p adjusted for correlated test [p ACT] < 0.05). For AA women, variants in RPTOR rs3817293 (intron), PIK3R1 rs7713645 (intron), and CDKAL1 rs9368197 were associated with decreased breast cancer risk. The significance for FRAP1 rs12125777 and RPTOR rs9900506 in EA women did not hold after correction for multiple comparisons. The risk associated with FRAP1 rs12125777 was higher among EAs who had body mass index ≥30 kg/m(2) (odds ratio = 7.69, 95 % CI 2.11-28.0; p-interaction = 0.007) and gained weight ≥35 lb since age 20 (odds ratio = 3.34, 95 % CI 1.42-7.85; p-interaction = 0.021), compared to their counterparts.

CONCLUSIONS

The mTOR pathway may be involved in breast cancer carcinogenesis differently for EA and AA women.

Obesity, weight gain, and ovarian cancer risk in African American women

Although there is growing evidence that higher adiposity increases ovarian cancer risk, little is known about its impact in African American (AA) women, the racial/ethnic group with the highest prevalence of obesity. We evaluated the impact of body mass index (BMI) 1 year before diagnosis and weight gain since age 18 years on ovarian cancer risk in a population-based case-control study in AA women in 11 geographical areas in the US. Cases (n = 492) and age and site matched controls (n = 696) were identified through rapid case ascertainment and random-digit-dialing, respectively. Information was collected on demographic and lifestyle factors, including self-reported height, weight at age 18 and weight 1 year before diagnosis/interview. Multivariable logistic regression was used to compute odds ratios (OR) and 95% confidence intervals (CI), adjusting for potential covariates. Obese women had elevated ovarian cancer risk, particularly for BMI ≥ 40 kg/m(2) compared to BMI <25 (OR = 1.72, 95% CI: 1.12-2.66; p for trend: 0.03). There was also a strong association with weight gain since age 18 (OR: 1.52; 95% CI: 1.07-2.16; p for trend: 0.02) comparing the highest to lowest quartile. In stratified analyses by menopausal status, the association with BMI and weight gain was limited to postmenopausal women, with a 15% (95% CI: 1.05-1.23) increase in risk per 5 kg/m(2) of BMI and 6% (95% CI: 1.01-1.10) increase in risk per 5 kg of weight gain. Excluding hormone therapy users essentially did not change results. Obesity and excessive adult weight gain may increase ovarian cancer risk in post-menopausal AA women.

Genetic variants in the mTOR pathway and breast cancer risk in African American women

The phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin (mTOR) pathway has been implicated in breast carcinogenesis. However, there has been no large-scale investigation of genetic variants in the mTOR pathway and breast cancer risk. We examined 28847 single-nucleotide polymorphisms (SNPs) in 61 mTOR pathway genes in the African American Breast Cancer Epidemiology and Risk consortium of 3663 cases [1983 estrogen receptor-positive (ER+) and 1098 ER-negative (ER-)] and 4687 controls. Gene-level analyses were conducted using the adaptive rank truncated product (ARTP) test for 10773 SNPs that were not highly correlated (r (2) < 0.8), and SNP-level analyses were conducted with logistic regression. Among genes that were prioritized (nominal P < 0.05, ARTP tests), associations were observed for intronic SNPs TSC2 rs181088346 [odds ratio (OR) of each copy of variant allele = 0.77, 95% confidence interval (CI) = 0.65-0.88 for all breast cancer] and BRAF rs114729114 (OR = 1.53, 95% CI = 1.24-1.91 for all breast cancer and OR = 2.03, 95% CI = 1.50-2.76 for ER- tumors). For ER- tumors, intronic SNPs PGF rs11542848 (OR = 1.38, 95% CI = 1.15-1.66) and rs61759375 (OR = 1.34, 95% CI = 1.14-1.57) and MAPK3 rs78564187 (OR = 1.26, 95% CI = 1.11-1.43) were associated with increased risk. These SNPs were significant at a gene-wide level (Bonferroni-corrected P < 0.05). The variant allele of RPS6KB2 rs35363135, a synonymous coding SNP, was more likely to be observed in ER- than ER+ tumors (OR = 1.18, 95% CI = 1.05-1.31, gene-wide Bonferroni-corrected P = 0.06). In conclusion, specific mTOR pathway genes are potentially important to breast cancer risk and to the ER negativity in African American women.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Associations between sociodemographic and clinicopathological factors and breast cancer subtypes in a population-based study

PURPOSE

This study examines the factors distinguishing breast cancer (BC) subtypes.

METHODS

We examined subtypes in 629 women with invasive BC, diagnosed from 2006 to 2012, and enrolled in an epidemiological study in New Jersey. Using molecular characteristics from pathology reports, BCs were categorized as luminal A, luminal B, non-luminal HER2-expressing, or triple-negative breast cancer (TNBC) subtypes. Multinomial logistic models (luminal A as referent) were used to describe BC subtype associations.

RESULTS

Women with luminal B tumors were more likely to be younger at diagnosis [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0-3.4] and to have higher-grade (OR 2.6, 95% CI 1.5-4.7), larger (OR 1.9, 95% CI 1.0-3.6), and Ki67-positive tumors (OR 2.1, 95% CI 1.1-4.0). Women with non-luminal HER2-expressing BCs were more likely to have higher-grade tumors (OR 14.5, 95% CI 5.3-39.7). Women with TNBCs were more likely to be African-American (OR 1.9, 95% CI 1.0-3.4) and to have higher-grade (OR 9.7, 95% CI 5.1-18.4), larger (OR 2.2, 95% CI 1.0-4.8), and Ki67-positive (OR 2.9, 95% CI 1.6-5.2) tumors. Notably, compared to the luminal A subtype, luminal B, non-luminal HER2-expressing, and triple-negative subtypes were more frequently self-detected; however, these associations were attenuated in multivariable models.

CONCLUSIONS

These findings suggest that some BC subtypes were associated with features denoting more aggressive phenotypes, namely higher grade, larger size, and Ki67 positivity, and possibly patient self-detection among some women. These findings highlight a need for enhanced screening, particularly among younger women, racial/ethnic minorities, and lower socioeconomic subgroups.

African Americans and Hispanics Remain at Lower Risk of Ovarian Cancer Than Non-Hispanic Whites after Considering Nongenetic Risk Factors and Oophorectomy Rates

BACKGROUND

Risk factors for invasive epithelial ovarian cancer (IEOC) among Hispanics and African Americans are understudied despite notable differences in incidence relative to non-Hispanic whites.

METHODS

We used multivariate logistic regression to examine parity, oral contraceptive use, tubal ligation, endometriosis, family history of ovarian cancer, and talc use and risk of IEOC among Hispanics (308 cases and 380 controls), African Americans (128 cases and 143 controls), and non-Hispanic whites (1,265 cases and 1,868 controls) using four case-control studies we conducted in Los Angeles County. We expressed each of these factors in the form of increasing risk and calculated population attributable risk percentage (PAR%) estimates for the six risk factors separately and jointly in the three groups.

RESULTS

The risk associations with these six well-accepted factors were comparable in the three groups. The significant racial/ethnic differences in the prevalence of these factors and differences in their oophorectomy rates explained 31% of the lower incidence in African Americans compared with non-Hispanic whites, but only 13% of the lower incidence in Hispanics. The PAR%s ranged from 27.5% to 31.0% for no tubal ligation, 15.9% to 22.2% for not using oral contraceptives, and 12.2% to 15.1% for using talc in the three groups.

CONCLUSIONS

All six risk factors are comparably important in the three groups. Differences in the prevalence of these factors and their oophorectomy rates explained approximately one third of the difference in incidence between African Americans and non-Hispanic whites.

IMPACT

Devising strategies to lessen the burden of IEOC will be applicable to all three racial/ethnic groups.

Obesity, body fat distribution, and risk of breast cancer subtypes in African American women participating in the AMBER Consortium

African American (AA) women are more likely than white women to be obese and to be diagnosed with ER- and triple-negative (TN) breast cancer, but few studies have evaluated the impact of obesity and body fat distribution on breast cancer subtypes in AA women. We evaluated these associations in the AMBER Consortium by pooling data from four large studies. Cases were categorized according to hormone receptor status as ER+, ER-, and TN (ER-, PR-, and HER2-) based on pathology data. A total of 2104 ER+ cases, 1070 ER- cases (including 491 TN cases), and 12,060 controls were included. Odds ratios (OR) and 95 % confidence intervals (CI) were computed using logistic regression, taking into account breast cancer risk factors. In postmenopausal women, higher recent (most proximal value to diagnosis/index date) BMI was associated with increased risk of ER+ cancer (OR 1.31; 95 % CI 1.02-1.67 for BMI ≥ 35 vs. <25 kg/m(2)) and with decreased risk of TN tumors (OR 0.60; 95 % CI 0.39-0.93 for BMI ≥ 35 vs. <25). High young adult BMI was associated with decreased premenopausal ER+ cancer and all subtypes of postmenopausal cancer, and high recent waist-to-hip ratio with increased risk of premenopausal ER+ tumors (OR 1.35; 95 % CI 1.01-1.80) and all tumor subtypes combined in postmenopausal women (OR 1.26; 95 % CI 1.02-1.56). The impact of general and central obesity varies by menopausal status and hormone receptor subtype in AA women. Our findings imply different mechanisms for associations of adiposity with TN and ER+ breast cancers.

A case-control analysis of oral contraceptive use and breast cancer subtypes in the African American Breast Cancer Epidemiology and Risk Consortium

Introduction

Recent oral contraceptive (OC) use has been consistently associated with increased risk of breast cancer, but evidence on specific breast cancer subtypes is sparse.

Methods

We investigated recency and duration of OC use in relation to molecular subtypes of breast cancer in a pooled analysis of data from the African American Breast Cancer Epidemiology and Risk Consortium. The study included 1,848 women with estrogen receptor-positive (ER+) breast cancer, 1,043 with ER-negative (ER-) breast cancer (including 494 triple negative (TN) tumors, which do not have receptors for estrogen, progesterone, and human epidermal growth factor 2), and 10,044 controls. Multivariable polytomous logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for exposure categories relative to never use, controlling for potential confounding variables.

Results

OC use within the previous 5 years was associated with increased risk of ER+ (OR 1.46, 95% CI 1.18 to 1.81), ER- (OR 1.57, 95% CI 1.22 to 1.43), and TN (OR 1.78, 95% CI 1.25 to 2.53) breast cancer. The risk declined after cessation of use but was apparent for ER+ cancer for 15 to 19 years after cessation and for ER- breast cancer for an even longer interval after cessation. Long duration of use was also associated with increased risk of each subtype, particularly ER-.

Conclusions

Our results suggest that OC use, particularly recent use of long duration, is associated with an increased risk of ER+, ER-, and TN breast cancer in African American women. Research into mechanisms that explain these findings, especially the association with ER- breast cancer, is needed.

Epidemiology, biology, and treatment of triple-negative breast cancer in women of African ancestry

Breast cancer incidence is increasing worldwide, and breast cancer-related mortality is highest in women of African ancestry, who are more likely to have basal-like or triple-negative breast cancer (TNBC) than are women of European ancestry. Identification of cultural, epidemiological, and genetic risk factors that predispose women of African ancestry to TNBC is an active area of research. Despite the aggressive behaviour of TNBC, achievement of a pathological complete response with chemotherapy is associated with good long-term survival outcomes, and sensitivity to chemotherapy does not seem to differ according to ethnic origin. Discovery of the molecular signalling molecules that define TNBC heterogeneity has led to the development of targeted agents such as inhibitors of poly (ADP-ribose) polymerase-1 and mTOR and immunomodulatory drugs that are in the early stages of clinical testing. First, we summarise the existing published work on the differences reported on the epidemiology, biology, and response to systemic treatment of TNBC between women of African ancestry and white women, and identify some gaps in knowledge. Second, we review the opportunities for development of new therapeutic agents in view of the potential high clinical relevance for patients with TNBC irrespective of race or ethnic origin.