Neighborhood Disadvantage, African Genetic Ancestry, Cancer Subtype, and Mortality Among Breast Cancer Survivors.

Importance: Racial disparities in breast cancer (BC) survival arise from multilevel causes, which may exert influence at different stages of BC progression. Clarifying the importance of genetic and social factors could help prioritize interventions. Objective: To jointly examine associations between African genetic ancestry, social environment, and mortality from any cause and BC in Black BC survivors. Design, Setting, and Participants: This population-based cohort study enrolled self-identified Black women aged 20 to 75 years with histologically confirmed BC from June 2005 to May 2019 and followed them up until death or censoring in September 2021. Participants lived in 10 New Jersey counties. Data were analyzed between December 2022 and April 2023. Exposures: A neighborhood socioeconomic status (nSES) index composed of census tract measures (education, income, wealth, employment status, and occupation) was linked to residential addresses at diagnosis. Percentage African ancestry was estimated using the ADMIXTURE program. Main Outcomes and Measures: Sequentially adjusted (age adjusted: age and interview year; fully adjusted: age adjusted with individual SES, lifestyle factors, and comorbidities) logistic regression models were fit to estimate associations with tumor subtypes (estrogen receptor-negative [ER-] vs estrogen receptor-positive [ER+]; triple-negative breast cancer [TNBC] vs luminal A), and Cox models were fit for associations with all-cause mortality (ACM) and breast cancer-specific mortality (BCSM). Models for BCSM were fit using Fine-Gray competing risks models, and robust standard errors were used to account for census tract-level clustering. Results: Among 1575 participants, median (IQR) African ancestry was 85% (76%-90%), and median (IQR) age was 55 (46-63) years. A 10-percentage point increase in African ancestry was associated with higher odds of ER- vs ER+ (adjusted odds ratio [aOR], 1.08; 95% CI, 0.98-1.18) and TNBC vs luminal (aOR, 1.15; 95% CI, 1.02-1.31) tumors, but not with ACM or BCSM. A 1-IQR increase in nSES was associated with lower ACM (adjusted hazard ratio [aHR], 0.76; 95% CI, 0.63-0.93), and the HR for BCSM was less than 1 but not statistically significant (aHR, 0.81; 95% CI, 0.62-1.04) in age-adjusted models, but associations attenuated following further adjustment for potential mediators (individual SES, lifestyles, comorbidities). Conclusions and Relevance: In this cohort study of Black female BC survivors, higher African ancestry was associated with aggressive tumor subtypes. Compared with genetic ancestry, mediating pathways related to social environments may be more important for survival in these patients.

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.

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.

Caffeic Acid Phenethyl Ester (CAPE) derived from propolis, a honeybee product, inhibits growth of breast cancer stem cells.

Cancer stem cells (CSC) are chemoresistant and implicated in tumor recurrence, metastasis and high patient mortality; thus substances impairing CSC activity, could be invaluable as novel cancer therapeutics. We previously showed that CAPE (caffeic acid phenethyl ester), a component of propolis, a honeybee product, inhibits growth of MDA-MB-231 (MDA-231) cells, mdr gene expression, NF-κB, EGFR, and VEGF. We hypothesized that CAPE also acts by interfering with CSC-mediated effects. We isolated breast CSC (bCSC) from MDA-231 cells, a model of human triple-negative breast cancer, and mouse xenografts. bCSC grow as mammospheres (MMS) and when dissociated into single cells, form MMS again, a sign of self-renewal. bCSC exhibited the characteristic CD44(+)/CD24(-/low) phenotype and generated progenitors in the presence of serum, a CSC trait responsible for regenerating tumor mass. CAPE caused dose-dependent bCSC self-renewal inhibition and progenitor formation. Clonal growth on soft agar was inhibited dose-dependently, but apoptosis was not induced as determined by Annexin-V/PI assay. Instead, bCSC were noted to significantly progress from a quiescent cell cycle state in G0/G1 (82%), S phase (12%) to a cycling state with an increase in S phase (41%) and subsequent decrease in G0/G1 (54%). Treatment of bCSC with CAPE (4.5-days) decreased CD44 levels by 95%, while another cell population containing 10-100-fold lower CD44 content concurrently increased. Results suggest that CAPE causes pronounced changes in bCSC characteristics manifested by inhibition of self renewal, progenitor formation, clonal growth in soft agar, and concurrent significant decrease in CD44 content, all signs of decreased malignancy potential.