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.

Adherence to Cancer Prevention Lifestyle Recommendations Before, During, and 2 Years After Treatment for High-risk Breast Cancer

Importance

The American Institute for Cancer Research and American Cancer Society regularly publish modifiable lifestyle recommendations for cancer prevention. Whether these recommendations have an impact on high-risk breast cancer survival remains unknown.

Objective

To investigate whether adherence to cancer prevention recommendations before, during, and 1 and 2 years after breast cancer treatment was associated with disease recurrence or mortality.

Design, Setting, and Participants

The Diet, Exercise, Lifestyles, and Cancer Prognosis Study (DELCaP) was a prospective, observational cohort study designed to assess lifestyles before diagnosis, during treatment, and at 1 and 2 years after treatment completion, implemented ancillary to the Southwest Oncology Group (SWOG) S0221 trial, a multicenter trial that compared chemotherapy regimens in breast cancer. Participants were chemotherapy-naive patients with pathologic stage I to III high-risk breast cancer, defined as node-positive disease with hormone receptor-negative tumors larger than 1 cm or any tumor larger than 2 cm. Patients with poor performance status and comorbidities were excluded from S0221. The study was conducted from January 1, 2005, to December 31, 2010; mean (SD) follow-up time for those not experiencing an event was 7.7 (2.1) years through December 31, 2018. The analyses reported herein were performed from March 2022 to January 2023.

Exposure

An aggregated lifestyle index score comprising data from 4 time points and 7 lifestyles, including (1) physical activity, (2) body mass index, (3) fruit and vegetable consumption, (4) red and processed meat intake, (5) sugar-sweetened beverage consumption, (6) alcohol consumption, and (7) smoking. Higher scores indicated healthier lifestyle.

Main Outcomes and Measures

Disease recurrence and all-cause mortality.

Results

A total of 1340 women (mean [SD] age, 51.3 [9.9] years) completed the baseline questionnaire. Most patients were diagnosed with hormone-receptor positive breast cancer (873 [65.3%]) and completed some education beyond high school (954 [71.2%]). In time-dependent multivariable analyses, patients with highest vs lowest lifestyle index scores experienced a 37.0% reduction in disease recurrence (hazard ratio, 0.63; 95% CI, 0.48-0.82) and a 58.0% reduction in mortality (hazard ratio, 0.42; 95% CI, 0.30-0.59).

Conclusions and Relevance

In this observational study of patients with high-risk breast cancer, strongest collective adherence to cancer prevention lifestyle recommendations was associated with significant reductions in disease recurrence and mortality. Education and implementation strategies to help patients adhere to cancer prevention recommendations throughout the cancer care continuum may be warranted in breast cancer.

An epigenome-wide analysis of socioeconomic position and tumor DNA methylation in breast cancer patients

BACKGROUND

Disadvantaged socioeconomic position (SEP), including lower educational attainment and household income, may influence cancer risk and outcomes. We hypothesized that DNA methylation could function as an intermediary epigenetic mechanism that internalizes and reflects the biological impact of SEP.

METHODS

Based on tumor DNA methylation data from the Illumina 450 K array from 694 breast cancer patients in the Women's Circle of Health Study, we conducted an epigenome-wide analysis in relation to educational attainment and household income. Functional impact of the identified CpG sites was explored in silico using data from publicly available databases.

RESULTS

We identified 25 CpG sites associated with household income at an array-wide significance level, but none with educational attainment. Two of the top CpG sites, cg00452016 and cg01667837, were in promoter regions of NNT and GPR37, respectively, with multiple epigenetic regulatory features identified in each region. NNT is involved in β-adrenergic stress signaling and inflammatory responses, whereas GPR37 is involved in neurological and immune responses. For both loci, gene expression was inversely correlated to the levels of DNA methylation. The associations were consistent between Black and White women and did not differ by tumor estrogen receptor (ER) status.

CONCLUSIONS

In a large breast cancer patient population, we discovered evidence of the significant biological impact of household income on the tumor DNA methylome, including genes in the β-adrenergic stress and immune response pathways. Our findings support biological effects of socioeconomic status on tumor tissues, which might be relevant to cancer development and progression.

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.

A prospective study of lifestyle factors and bone health in breast cancer patients who received aromatase inhibitors in an integrated healthcare setting

PURPOSE

Fracture and osteoporosis are known side effects of aromatase inhibitors (AIs) for postmenopausal hormone receptor positive (HR+) breast cancer (BC) patients. How modifiable lifestyle factors impact fracture risk in these patients is relatively unknown.

METHODS

We conducted a prospective cohort study to examine the association of lifestyle factors, focusing on physical activity, with risk of incident major osteoporotic fracture and osteoporosis in 2152 HR+ BC patients diagnosed from 2006 to 2013 at Kaiser Permanente Northern California and who received AIs. Patients self-reported lifestyle factors at study entry and at 6-month follow-up. Fracture and osteoporosis outcomes were prospectively ascertained by physician-adjudication and bone mineral density (BMD) values, respectively. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from multivariable proportional hazards regression. Models were adjusted for age, menopausal status, race/ethnicity, body mass index (BMI), AJCC stage, breast cancer treatment, prior osteoporosis, and prior major fracture.

RESULTS

Over a median 6.1 years of follow-up after AI initiation, 165 women experienced an incident osteoporotic fracture and 243 women had osteoporosis. No associations were found between overall moderate-vigorous physical activity and fracture risk, although < 150 min/week of aerobic exercise in the 6 months after BC diagnosis was associated with increased fracture risk (HR=2.42; 95% CI: 1.34, 4.37) compared with ≥ 150 min/week (meeting physical activity guidelines). Risk was also higher for never or infrequently engaging in aerobic exercise (HR=1.90; 95% CI: 1.05, 3.44). None or infrequent overall moderate-vigorous physical activity in the 6 months before BC diagnosis was associated with increased risk of osteoporosis (HR=1.94; 95% CI: 1.11; 3.37).

CONCLUSIONS

Moderate-vigorous physical activity during the immediate period after BC diagnosis, particularly aerobic exercise, was associated with lower risk of major osteoporotic fractures in women on AI therapy.

IMPLICATIONS FOR CANCER SURVIVORS

Findings may inform fracture prevention in women on AI therapy through non-pharmacologic lifestyle-based strategies.

Association of Cigarette Smoking and Alcohol Consumption With Subsequent Mortality Among Black Breast Cancer Survivors in New Jersey

IMPORTANCE

There are limited data about how lifestyle factors are associated with breast cancer prognosis among Black or African American women because most of the evidence is based on studies of White breast cancer survivors.

OBJECTIVE

To examine the association of prediagnostic cigarette smoking and alcohol consumption with all-cause mortality and breast cancer-specific mortality in a cohort of Black breast cancer survivors.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included 1926 Black or African American breast cancer survivors who received a diagnosis from June 6, 2005, to May 21, 2019, identified in 10 counties in New Jersey through rapid case ascertainment by the New Jersey State Cancer Registry. Statistical analysis was conducted from January 1, 2021, to August 1, 2022.

EXPOSURES

Information on prediagnostic cigarette smoking, alcohol consumption, and additional covariates was collected during in-person interviews. The covariates examined included smoking status at the time of breast cancer diagnosis (currently smoking at the time of breast cancer diagnosis, formerly smoking, or never smoking), smoking duration (number of years smoking), smoking intensity (cigarettes smoked per day), number of pack-years of smoking, and regular alcohol consumption the year before diagnosis (categorized as nondrinkers, ≤3 drinks per week, or >3 drinks per week).

MAIN OUTCOMES AND MEASURES

Primary outcomes included breast cancer-specific mortality and all-cause mortality.

RESULTS

Among the 1926 women in the study, the mean (SD) age at breast cancer diagnosis was 54.4 (10.8) years. During 13 464 person-years of follow-up (median follow-up, 6.7 years [range, 0.5-16.0 years]), there were 337 deaths, of which 187 (55.5%) were breast cancer related. Compared with never smokers, current smokers at the time of breast cancer diagnosis had a 52% increased risk for all-cause mortality (hazard ratio [HR], 1.52; 95% CI, 1.15-2.02), which was most pronounced for those with 10 or more pack-years of smoking (HR, 1.84; 95% CI, 1.34-2.53). Similar findings were observed for breast cancer-specific mortality (current smokers vs never smokers: HR, 1.27; 95% CI, 0.87-1.85), although they were not statistically significant. There was no statistically significant association between alcohol consumption and all-cause mortality (>3 drinks per week vs nondrinkers: HR, 1.05; 95% CI, 0.73-1.51) or breast cancer-specific mortality (>3 drinks per week vs nondrinkers: HR, 1.06; 95% CI, 0.67-1.67).

CONCLUSIONS AND RELEVANCE

This population-based cohort study of Black breast cancer survivors suggests that current smoking at the time of diagnosis was associated with an increased risk of all-cause mortality, particularly among women with greater pack-years of smoking.

A biopsychosocial model to understand racial disparities in the era of cancer immunotherapy

The approval and wide uptake of immune checkpoint inhibitors (ICIs) in oncology practice raise the concerns of possibly worsened racial disparities in cancer treatment due to biological and psychosocial reasons. We propose a multilevel biopsychosocial model to understand the opportunities and challenges to racial disparities in the era of cancer immunotherapy.

Smoking Behaviors and Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer in the Be-Well Study

Importance

Tobacco smoking is an established risk factor associated with bladder cancer, yet its impact on bladder cancer prognosis is unclear.

Objective

To examine associations of use of tobacco (cigarettes, pipes, and cigars), e-cigarettes, and marijuana with risk of recurrence and progression of non-muscle-invasive bladder cancer (NMIBC) and to explore use of smoking cessation interventions.

Design, Setting, and Participants

The Be-Well Study is a prospective cohort study of patients with NMIBC diagnosed from 2015 to 2019 and followed-up for 26.4 months in the Kaiser Permanente Northern and Southern California integrated health care system. Eligibility criteria were age at least 21 years, first NMIBC diagnosis (stages Ta, Tis, or T1), alive, and not in hospice care. Exclusion criteria were previous diagnosis of bladder cancer or other cancer diagnoses within 1 year prior to or concurrent with NMIBC diagnosis. Data were analyzed from April 1 to October 4, 2022.

Exposures

Use of cigarettes, pipes, cigars, e-cigarettes, and marijuana was reported in the baseline interview. Use of smoking cessation interventions (counseling and medications) was derived from electronic health records.

Main Outcomes and Measures

Hazard ratios (HRs) and 95% CIs of recurrence and progression of bladder cancer were estimated by multivariable Cox proportional hazards regression.

Results

A total of 1472 patients (mean [SD] age at diagnosis, 70.2 [10.8%] years; 1129 [76.7%] male patients) with NMIBC were enrolled at a mean (SD) of 2.3 (1.3) months after diagnosis, including 874 patients (59.4%) who were former smokers and 111 patients (7.5%) who were current cigarette smokers; 67 patients (13.7%) smoked pipes and/or cigars only, 65 patients (4.4%) used e-cigarettes, 363 patients (24.7%) used marijuana. Longer cigarette smoking duration and more pack-years were associated with higher risk of recurrence in a dose-dependent manner, with the highest risks for patients who had smoked for 40 or more years (HR, 2.36; 95% CI, 1.43-3.91) or 40 or more pack-years (HR, 1.97; 95% CI, 1.32-2.95). There was no association of having ever smoked, being a former or current cigarette smoker, and years since quit smoking with recurrence risk. No associations with pipes, cigars, e-cigarettes, or marijuana were found. Of 102 patients offered a smoking cessation intervention, 57 (53.8%) received an interventions after diagnosis, with female patients more likely than male patients to engage in such interventions (23 of 30 female patients [76.7%] vs 34 of 76 male patients [44.7%]; P = .003).

Conclusions and Relevance

These findings suggest that longer duration and more pack-years of cigarette smoking were associated with higher risk of NMIBC recurrence. Cigarette smoking remains a critical exposure before and after diagnosis in survivors of NMIBC.

Physical activity, sedentary time and breast cancer risk: a Mendelian randomisation study

OBJECTIVES

Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics.

METHODS

We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105-377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (nsnps=5) or sedentary time (nsnps=6), or accelerometer-measured (nsnps=1) or self-reported (nsnps=5) vigorous physical activity.

RESULTS

Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;~8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,≥3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (~7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger).

CONCLUSION

Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women.

Associations between Serum 25-hydroxyvitamin D Levels and Health-Related Quality-of-Life Measures in Breast Cancer Patients: A Longitudinal Study

BACKGROUND

Recent evidence suggests that vitamin D might lower breast cancer mortality. There is also growing interest in vitamin D's potential association with health-related quality-of-life (HRQoL). Associations between circulating 25OHD concentrations and HRQoL were examined prospectively among breast cancer survivors at the time of diagnosis and 1-year later.

METHODS

504 women with incident early-stage breast cancer at Roswell Park Comprehensive Cancer Center were included, and 372 patients provided assessments one year later. At each timepoint, participants provided blood samples and completed the SF-36 Health Survey, and surveys on perceived stress, depression, and fatigue. Season-adjusted serum 25OHD concentrations were analyzed in relation to HRQoL measures using multivariable logistic regression models.

RESULTS

Approximately 32% of participants had deficient vitamin D levels at diagnosis, which decreased to 25% at 1-year. Concurrently, although SF-36 physical health summary scores were lower at 1-year, mental health summary scores improved, and levels of depression and perceived stress were lower. In comparison to women with sufficient 25OHD levels (>30 ng/ml) at diagnosis, those who were deficient (<20 ng/ml) had significantly worse HRQoL at diagnosis and 1 year later. Vitamin D deficiency 1-year post-diagnosis was also associated with worse HRQoL, particularly among breast cancer survivors who took vitamin D supplements.

CONCLUSIONS

Breast cancer survivors with vitamin D deficiency were more likely to report lower HRQoL than those with sufficient levels at the time of diagnosis and 1-year post-diagnosis.

IMPACT

Our results indicate a potential benefit of vitamin D supplementation for improving breast cancer survivorship.  .

Polygenic risk scores for prediction of breast cancer risk in women of African ancestry: a cross-ancestry approach

Polygenic risk scores (PRSs) are useful for predicting breast cancer risk, but the prediction accuracy of existing PRSs in women of African ancestry (AA) remains relatively low. We aim to develop optimal PRSs for the prediction of overall and estrogen receptor (ER) subtype-specific breast cancer risk in AA women. The AA dataset comprised 9235 cases and 10 184 controls from four genome-wide association study (GWAS) consortia and a GWAS study in Ghana. We randomly divided samples into training and validation sets. We built PRSs using individual-level AA data by a forward stepwise logistic regression and then developed joint PRSs that combined (1) the PRSs built in the AA training dataset and (2) a 313-variant PRS previously developed in women of European ancestry. PRSs were evaluated in the AA validation set. For overall breast cancer, the odds ratio per standard deviation of the joint PRS in the validation set was 1.34 [95% confidence interval (CI): 1.27-1.42] with the area under receiver operating characteristic curve (AUC) of 0.581. Compared with women with average risk (40th-60th PRS percentile), women in the top decile of the PRS had a 1.98-fold increased risk (95% CI: 1.63-2.39). For PRSs of ER-positive and ER-negative breast cancer, the AUCs were 0.608 and 0.576, respectively. Compared with existing methods, the proposed joint PRSs can improve prediction of breast cancer risk in AA women.

Results and lessons from dual extraction of DNA and RNA from formalin-fixed paraffin-embedded breast tumor tissues for a large Cancer epidemiologic study

BACKGROUND

The use of archived formalin-fixed paraffin-embedded (FFPE) tumor tissues has become a common practice in clinical and epidemiologic genetic research. Simultaneous extraction of DNA and RNA from FFPE tissues is appealing but can be practically challenging. Here we report our results and lessons learned from processing FFPE breast tumor tissues for a large epidemiologic study.

METHODS

Qiagen AllPrep DNA/RNA FFPE kit was adapted for dual extraction using tissue punches or sections from breast tumor tissues. The yield was quantified using Qubit and fragmentation analysis by Agilent Bioanalyzer. A subset of the DNA samples were used for genome-wide DNA methylation assays and RNA samples for sequencing. The QC metrices and performance of the assays were analyzed with pre-analytical variables.

RESULTS

A total of 1859 FFPE breast tumor tissues were processed. We found it critical to adjust proteinase K digestion time based on tissue volume to achieve balanced yields of DNA and RNA. Tissue punches taken from tumor-enriched regions provided the most reliable output. A median of 1475 ng DNA and 1786 ng RNA per sample was generated. The median DNA integrity number (DIN) was 3.8 and median DV200 for RNA was 33.2. Of 1294 DNA samples used in DNA methylation assays, 97% passed quality check by qPCR and 92% generated data deemed high quality. Of the 130 RNA samples with DV200 ≥ 20% used in RNA-sequencing, all but 5 generated usable transcriptomic data with a mapping rate ≥ 60%.

CONCLUSIONS

Dual DNA/RNA purification using Qiagen AllPrep FFPE extraction protocol is feasible for clinical and epidemiologic studies. We recommend tissue punches as a reliable source material and fine tuning of proteinase K digestion time based on tissue volume.

IMPACT

Our protocol and recommendations may be adapted by future studies for successful extraction of archived tumor tissues.

Proceedings of the fifth international Molecular Pathological Epidemiology (MPE) meeting

Cancer heterogeneities hold the key to a deeper understanding of cancer etiology and progression and the discovery of more precise cancer therapy. Modern pathological and molecular technologies offer a powerful set of tools to profile tumor heterogeneities at multiple levels in large patient populations, from DNA to RNA, protein and epigenetics, and from tumor tissues to tumor microenvironment and liquid biopsy. When coupled with well-validated epidemiologic methodology and well-characterized epidemiologic resources, the rich tumor pathological and molecular tumor information provide new research opportunities at an unprecedented breadth and depth. This is the research space where Molecular Pathological Epidemiology (MPE) emerged over a decade ago and has been thriving since then. As a truly multidisciplinary field, MPE embraces collaborations from diverse fields including epidemiology, pathology, immunology, genetics, biostatistics, bioinformatics, and data science. Since first convened in 2013, the International MPE Meeting series has grown into a dynamic and dedicated platform for experts from these disciplines to communicate novel findings, discuss new research opportunities and challenges, build professional networks, and educate the next-generation scientists. Herein, we share the proceedings of the Fifth International MPE meeting, held virtually online, on May 24 and 25, 2021. The meeting consisted of 21 presentations organized into the three main themes, which were recent integrative MPE studies, novel cancer profiling technologies, and new statistical and data science approaches. Looking forward to the near future, the meeting attendees anticipated continuous expansion and fruition of MPE research in many research fronts, particularly immune-epidemiology, mutational signatures, liquid biopsy, and health disparities.

Multilevel Factors for Adiposity Change in a Population-Based Prospective Study of Black Breast Cancer Survivors

PURPOSE

Unfavorable weight change after breast cancer diagnosis increases the risk of mortality, but individual and neighborhood risk factors affecting postdiagnosis weight and body fat changes are unclear among Black women, who have higher rates of obesity and mortality than any other racial/ethnic group.

METHODS

Adiposity changes during the period approximately 10 months-24 months after diagnosis were evaluated among 785 women diagnosed between 2012 and 2018 and enrolled in the Women's Circle of Health Follow-Up Study, a population-based prospective cohort of Black breast cancer survivors in New Jersey. Multilevel factors for weight and fat mass change (with gain or loss defined as a relative difference of 3% or more, and considering whether changes were intentional or unintentional) were estimated using multivariable polytomous logistic regressions and multilevel models.

RESULTS

Adiposity gain was prevalent: 28% and 47% gained weight and body fat, respectively, despite a high baseline prevalence of overweight or obesity (86%). Risk factors for fat mass gain included receiving chemotherapy (relative risk ratio: 1.59, 95% CI, 1.08 to 2.33) and residing in neighborhoods with a greater density of fast-food restaurants (relative risk ratio comparing highest with lowest tertile: 2.18, 95% CI, 1.38 to 3.46); findings were similar for weight gain. Only 9% of women had intentional weight loss, and multilevel risk factors differed vastly from unintentional loss.

CONCLUSION

Both individual and neighborhood factors were associated with adiposity change among Black breast cancer survivors. Residential environment characteristics may offer clinically meaningful information to identify cancer survivors at higher risk for unfavorable weight change and to address barriers to postdiagnosis weight management.

Abstract 714: Weight changes between one year before and following breast cancer diagnosis in relation to mTOR protein expression in tumor tissues in the Women’s Circle of Health Study

Background: Obesity is an important prognostic factor for breast cancer. Aberrant activation of the mechanistic Target of Rapamycin (mTOR) pathway is associated with obesity, cross-sectionally, as well as with breast cancer survival. This study aimed to examine the association of weight change between one year before and following cancer diagnosis with a panel of mTOR protein markers in breast tumors. The study hypothesis was that greater weight gain compared to less or no weight gain would be associated with higher mTOR protein expression in breast tumors.

Methods: Study participants were 698 newly-diagnosed breast cancer cases (545 Black women and 153 White women) from the Women’s Circle of Health Study (WCHS). Surgical tissue microarrays were stained for mTOR, phosphorylated mTOR, phosphorylated AKT, and phosphorylated P70S6K using immunohistochemistry. In-home interviews were conducted approximately 10 months after breast cancer diagnosis, and anthropometric measurement was taken by trained staff. Participants reported body weight one year before the diagnosis, excluding the time of pregnancy or nursing. Linear regression analyses were conducted to estimate percent differences in protein expression across quartiles of weight change, adjusting for age, race, BMI one year before diagnosis, menopausal status, history of diabetes, and molecular tumor subtype.

Results: Study participants had a mean age of 52.7 (SD = 10.8) years and BMI one year before diagnosis of 30.7 (SD = 6.9) kg/m2. The proportions of participants who had loss ≥5 lbs, loss &lt;5 lbs, no change to gain &lt;5 lbs, and gain ≥5 lbs in weight were 33.7%, 16.2%, 16.2%, and 33.7%, respectively. The fourth vs. first quartile of the weight change was associated with a higher protein expression of mTOR (35.3%, 95% CI = 3.8%, 76.5%), and there was a dose-response pattern (P-trend = 0.0273). No associations were observed between weight change and phosphorylated protein expression.

Conclusion: Short-term weight gain before breast cancer diagnosis and following diagnosis may play a role in breast tumor mTOR protein expression. Our findings warrant validation in a study with a prospective measurement of weight gain before breast cancer surgery.

Citation Format: Mmadili N. Ilozumba, Angela R. Omilian, Song Yao, Weizhou Zhang, Susmita Datta, Warren Davis, Chi-Chen Hong, Elisa V. Bandera, Thaer Khoury, Christine B. Ambrosone, Ting-Yuan David Cheng. Weight changes between one year before and following breast cancer diagnosis in relation to mTOR protein expression in tumor tissues in the Women’s Circle of Health Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 714.

Vitamin D insufficiency as a peripheral neuropathy risk factor in white and black patients in SWOG 0221

12023

Background: Peripheral neuropathy (PN) is a treatment-limiting toxicity of paclitaxel. Black patients have higher rates of PN and vitamin D insufficiency, and our prior work suggests vitamin D insufficiency increases risk of paclitaxel-induced PN. The objective of this study was to validate that patients with vitamin D insufficiency have higher risk of paclitaxel-induced PN and investigate whether this explains racial disparities in PN risk. Methods: This retrospective validation study was conducted in the phase III SWOG 0221 (NCT00070564) trial comparing paclitaxel-containing chemotherapy regimens for early-stage breast cancer. Pre-treatment 25-hydroxy-vitamin D was quantified in cryopreserved serum. Males and patients who received less than a third of the paclitaxel treatment were excluded. The association between vitamin D insufficiency (≤20 ng/mL) and grade 3+ sensory PN was tested via logistic regression and then adjusted for self-reported race, age, paclitaxel schedule (QW vs Q2W), and body mass index. Results: Of the 1,116 female patients in the analysis, 169 (15.1%) experienced PN and 376 (33.7%) had vitamin D insufficiency. Vitamin D insufficiency was associated with higher PN risk (19.4% vs 13.0%, OR = 1.62, p = 0.005, Data Table). The association was borderline significant (OR = 1.44, p = 0.056) after adjustment for black race (OR = 2.41, p = 0.001), paclitaxel schedule (OR = 2.22, p < 0.001), and age (OR = 1.03, p = 0.005). Compared with white patients (n = 943), black patients (n = 99) had more prevalent vitamin D insufficiency (77.8% vs 28.6%, OR = 8.72, p < 0.001) and increased PN risk (29.3% vs 13.5%, OR = 2.66, p < 0.001); adjusting for vitamin D insufficiency decreased but did not eliminate the higher PN risk in black patients (OR = 2.23, p = 0.002). Conclusions: Vitamin D insufficiency increases risk of paclitaxel-induced PN and partially explains the higher risk of PN in black patients. Prospective trials are needed to test whether vitamin D supplementation lessens PN and reduces disparities in treatment outcomes. [Table: see text]

A Presurgical-Window Intervention Trial of Isothiocyanate-Rich Broccoli Sprout Extract in Patients with Breast Cancer

SCOPE

Dietary isothiocyanates (ITCs) from cruciferous vegetables have shown potent anti-breast cancer activities in preclinical models, but their anticancer effects in vivo in breast cancer patients remain elusive. A proof-of-principle, presurgical window of opportunity trial is conducted to assess the anticancer effects of dietary ITCs in breast cancer patients.

METHODS AND RESULTS

Thirty postmenopausal breast cancer patients are randomly assigned to receive ITC-rich broccoli sprout extract (BSE) (200 µmol ITC per day) or a placebo for 2 weeks. Expression of biomarkers related to ITCs functions are measured in breast cancer tissue specimens at pre- and post-interventions using immunohistochemistry staining. First morning urine samples are collected at both timepoints for proteomic analysis. Overall, the study shows high compliance (100%) and low toxicity (no grade 4 adverse event). Trends of increase in cleaved caspase 3 and tumor-infiltrating lymphocytes (TILs) and trends of decrease in Ki-67 and nuclear to cytoplasm ratio of estrogen receptor (ER)-α are observed in the BSE arm only, consistent with the significantly altered signaling pathways identified in urinary proteomic analysis.

CONCLUSIONS

Anticancer activities of ITCs are observed in breast cancer patients, supporting the potential beneficial roles of ITC-containing cruciferous vegetables in breast cancer prognosis.

mTOR pathway gene expression in association with race and clinicopathological characteristics in Black and White breast cancer patients

BACKGROUND

Aberrant activation of the mammalian Target of Rapamycin (mTOR) pathway has been linked to obesity and endocrine therapy resistance, factors that may contribute to Black-White disparities in breast cancer outcomes. We evaluated associations of race and clinicopathological characteristics with mRNA expression of key mTOR pathway genes in breast tumors.

METHODS

Surgical tumor tissue blocks were collected from 367 newly diagnosed breast cancer patients (190 Black and 177 White). Gene expression of AKT1, EIF4EBP1, MTOR, RPS6KB2, and TSC1 were quantified by NanoString nCounter. Differential gene expression was assessed using linear regression on log2-transformed values. Gene expression and DNA methylation data from TCGA were used for validation and investigation of race-related differences.

RESULTS

Compared to White women, Black women had relative under-expression of AKT1 (log2 fold-change = - 0.31, 95% CI - 0.44, - 0.18) and RPS6KB2 (log2 fold-change = - 0.11, 95% CI - 0.19, - 0.03). Higher vs. lower tumor grade was associated with relative over-expression of EIF4EBP1 and RPS6KB2, but with lower expression of TSC1. Compared to luminal tumors, triple-negative tumors had relative under-expression of TSC1 (log2 fold-change = - 0.42, 95% CI - 0.22, - 0.01). The results were similar in the TCGA breast cancer dataset. Post-hoc analyses identified differential CpG methylation within the AKT1 and RPS6KB2 locus between Black and White women.

CONCLUSIONS

Over-expression of RPS6KB2 and EIF4EBP1 and under-expression of TSC1 might be indicators of more aggressive breast cancer phenotypes. Differential expression of AKT1 and RPS6KB2 by race warrants further investigation to elucidate their roles in racial disparities of treatment resistance and outcomes between Black and White women with breast cancer.

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.

Associations Between Polymorphisms in Genes Related to Oxidative Stress and DNA Repair, Interactions With Serum Antioxidants, and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial

Study of polymorphisms in genes related to the generation and removal of oxidative stress and repair of oxidative DNA damage will lead to new insights into the genetic basis of prostate cancer. In the Prostate Cancer Prevention Trial (PCPT), a double-blind, randomized controlled trial testing finasteride versus placebo for prostate cancer prevention, we intend to investigate the role of oxidative stress/DNA repair mechanisms in prostate cancer etiology and whether these polymorphisms modify prostate cancer risk by interacting with antioxidant status in both placebo and finasteride arms. We evaluated associations of selected candidate polymorphisms in genes in these pathways, and interactions with pre-diagnostic serum antioxidants, and the risk of prostate cancer among 1,598 cases and 1,706 frequency-matched controls enrolled in the PCPT. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable-adjusted logistic regression models. While there were no statistically significant associations observed in the placebo arm, several SNPs were associated with prostate cancer in the finasteride arm. Specifically, APEX1-rs1760944 was associated with increased risk of total prostate cancer (per minor allele: p-trend=0.04). OGG1-rs1052133 was positively (CG/GG vs. CC: OR=1.32, 95% CI: 1.01-1.73) and NOS3-rs1799983 was inversely (per minor allele: p-trend=0.04) associated with risk of low-grade prostate cancer. LIG3-rs1052536 and XRCC1-rs25489 were suggestively associated with reduced risk of high-grade prostate cancer (per minor allele: both p-trend=0.04). In the placebo arm, significant associations were observed among men with higher serum lycopene for APEX1-rs1760944 and NQO1-rs1800566, or higher serum β-cryptoxanthin for ERCC4-rs1800067. In the finasteride arm, stronger associations were observed among men with lower serum lycopene for NOS3-rs1799983, higher serum α-carotene, β-carotene, and β-cryptoxanthin for LIG3-rs1052536, or lower serum retinol for SOD2-rs1799725. These results suggest that germline variations in oxidative stress and DNA repair pathways may contribute to prostate carcinogenesis and that these associations may differ by intraprostatic sex steroid hormone status and be further modified by antioxidant status. Findings provide insights into the complex role of gene, gene-antioxidant and -finasteride interactions in prostate cancer etiology, and thus may lead to the development of preventative strategies.

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.

Germline Pathogenic Variants in Cancer Predisposition Genes Among Women With Invasive Lobular Carcinoma of the Breast

PURPOSE

To determine the contribution of germline pathogenic variants (PVs) in hereditary cancer testing panel genes to invasive lobular carcinoma (ILC) of the breast.

MATERIALS AND METHODS

The study included 2,999 women with ILC from a population-based cohort and 3,796 women with ILC undergoing clinical multigene panel testing (clinical cohort). Frequencies of germline PVs in breast cancer predisposition genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, PALB2, PTEN, RAD51C, RAD51D, and TP53) were compared between women with ILC and unaffected female controls and between women with ILC and infiltrating ductal carcinoma (IDC).

RESULTS

The frequency of PVs in breast cancer predisposition genes among women with ILC was 6.5% in the clinical cohort and 5.2% in the population-based cohort. In case-control analysis, CDH1 and BRCA2 PVs were associated with high risks of ILC (odds ratio [OR] > 4) and CHEK2, ATM, and PALB2 PVs were associated with moderate (OR = 2-4) risks. BRCA1 PVs and CHEK2 p.Ile157Thr were not associated with clinically relevant risks (OR < 2) of ILC. Compared with IDC, CDH1 PVs were > 10-fold enriched, whereas PVs in BRCA1 were substantially reduced in ILC.

CONCLUSION

The study establishes that PVs in ATM, BRCA2, CDH1, CHEK2, and PALB2 are associated with an increased risk of ILC, whereas BRCA1 PVs are not. The similar overall PV frequencies for ILC and IDC suggest that cancer histology should not influence the decision to proceed with genetic testing. Similar to IDC, multigene panel testing may be appropriate for women with ILC, but CDH1 should be specifically discussed because of low prevalence and gastric cancer risk.

A Validated Risk Prediction Model for Breast Cancer in US Black Women

PURPOSE

Breast cancer risk prediction models are used to identify high-risk women for early detection, targeted interventions, and enrollment into prevention trials. We sought to develop and evaluate a risk prediction model for breast cancer in US Black women, suitable for use in primary care settings.

METHODS

Breast cancer relative risks and attributable risks were estimated using data from Black women in three US population-based case-control studies (3,468 breast cancer cases; 3,578 controls age 30-69 years) and combined with SEER age- and race-specific incidence rates, with incorporation of competing mortality, to develop an absolute risk model. The model was validated in prospective data among 51,798 participants of the Black Women's Health Study, including 1,515 who developed invasive breast cancer. A second risk prediction model was developed on the basis of estrogen receptor (ER)-specific relative risks and attributable risks. Model performance was assessed by calibration (expected/observed cases) and discriminatory accuracy (C-statistic).

RESULTS

The expected/observed ratio was 1.01 (95% CI, 0.95 to 1.07). Age-adjusted C-statistics were 0.58 (95% CI, 0.56 to 0.59) overall and 0.63 (95% CI, 0.58 to 0.68) among women younger than 40 years. These measures were almost identical in the model based on estrogen receptor-specific relative risks and attributable risks.

CONCLUSION

Discriminatory accuracy of the new model was similar to that of the most frequently used questionnaire-based breast cancer risk prediction models in White women, suggesting that effective risk stratification for Black women is now possible. This model may be especially valuable for risk stratification of young Black women, who are below the ages at which breast cancer screening is typically begun.

Dietary Vitamin A and Breast Cancer Risk in Black Women: The African American Breast Cancer Epidemiology and Risk (AMBER) Consortium

BACKGROUND

Studies in women of European descent showed an inverse association of dietary vitamin A (retinol and carotenoids) intake with breast cancer risks, mainly in premenopausal women.

OBJECTIVES

We examined whether higher compared with lower levels of dietary vitamin A are associated with reduced breast cancer risks among Black women by estrogen receptor (ER) and menopausal statuses.

METHODS

In this pooled analysis, data were from 3564 breast cancer cases and 11,843 controls (mean ages = 56.4 and 56.3 years, respectively) in the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium. Dietary intake was assessed by FFQs. Multivariable logistic regressions were performed to estimate ORs and 95% CIs for study-specific quintiles of total vitamin A equivalents and individual carotenoids, and a pooled OR was estimated by a random-effect model.

RESULTS

We observed an inverse association of total vitamin A equivalents with ER-positive breast cancer (quintiles 5 compared with 1: pooled OR: 0.82; 95% CI: 0.67-1.00; P-trend = 0.045). The association was seen among premenopausal women (pooled OR: 0.60; 95% CI: 0.43-0.83; P-trend = 0.004), but not among postmenopausal women (pooled OR: 0.99; 95% CI: 0.77-1.28; P-trend = 0.78). Additionally, there were inverse associations of dietary β-carotene (quintiles 5 compared with 1: pooled OR: 0.70; 95% CI: 0.51-0.95; P-trend = 0.08) and lutein (pooled OR: 0.63; 95% CI: 0.45-0.87; P-trend = 0.020) with ER-positive breast cancer among premenopausal women. There was no evidence for an association of total vitamin A equivalents or individual carotenoids with ER-negative breast cancer, regardless of menopausal status.

CONCLUSIONS

Our findings on dietary vitamin A and breast cancer risks in Black women are consistent with observations in women of European descent and advance the literature showing an inverse association for ER-positive disease.