Breast cancer incidence and mortality by metabolic syndrome and obesity: The Women's Health Initiative.

BACKGROUND: In the Women's Health Initiative (WHI) randomized trial, dietary intervention significantly reduced breast cancer mortality, especially in women with more metabolic syndrome (MetS) components. Therefore, this study investigated the associations of MetS and obesity with postmenopausal breast cancer after long-term follow-up in the WHI clinical trials. METHODS: A total of 68,132 postmenopausal women, without prior breast cancer and with normal mammogram, were entered into WHI randomized clinical trials; 63,330 women with an entry MetS score comprised the study population. At entry, body mass index (BMI) was determined; MetS score (0, 1-2, and 3-4) included the following: (1) high waist circumference (≥88 cm), (2) high blood pressure (systolic ≥130 mm Hg and/or diastolic ≥85 mm Hg, or hypertension history), (3) high-cholesterol history, and (4) diabetes history. Study outcomes included breast cancer incidence, breast cancer mortality, deaths after breast cancer, and results by hormone receptor status. RESULTS: After a >20-year mortality follow-up, a higher MetS score (3-4), adjusted for BMI, was significantly associated with more poor prognosis, estrogen receptor (ER)-positive, progesterone receptor (PR)-negative cancers (p = .03), 53% more deaths after breast cancer (p < .001), and 44% higher breast cancer mortality (p = .03). Obesity status, adjusted for MetS score, was significantly associated with more good prognosis, ER-positive, PR-positive cancers (p < .001), more total breast cancers (p < .001), and more deaths after breast cancer (p < .001), with higher breast cancer mortality only in women with severe obesity (BMI, ≥35 kg/m2; p < .001). CONCLUSIONS: MetS and obesity status have independent, but differential, adverse associations with breast cancer receptor subtypes and breast cancer mortality risk. Both represent separate targets for breast cancer prediction and prevention strategies.

Long-term breast cancer incidence trends by mammography, obesity, and menopausal hormone therapy.

PURPOSE: Over the past half century, the annual age-adjusted breast cancer incidence in the USA has fluctuated, potentially influenced by changes in mammography screening, obesity, and menopausal hormone therapy. As the relative contributions of these factors on breast cancer incidence have not been resolved, we assembled reliable sources of year-to-year changes in mammography, obesity, and hormone therapy to graphically display their relationship to breast cancer incidence through 50 years. METHODS: Year-to-year trends were assembled: for mammography from the Center for Disease Control National Health Interviews; for hormone therapy from the Collaborative Group on Hormonal Factors in Breast Cancer report; for obesity from the NCD (Non-Communicable Diseases) Risk Factor Collaboration; and for breast cancer for US women 50-64 years of age from Surveillance, Epidemiology, and End Results (SEER) registry findings. RESULTS: Increases in age-adjusted breast cancer incidence trend from about 1982 to 2002 track both mammography and hormone therapy use but not obesity. However, the sudden decrease in breast cancer incidence in 2003, subsequently sustained at a lower incidence level, only tracks the parallel reduction in hormone therapy use. CONCLUSION: The sustained reduction in hormone therapy use from 2003 provides a plausible explanation for most of the lower breast cancer incidence seen in US postmenopausal women during the last two decades. The strong observational study obesity association with higher breast cancer risk is not reflected in breast cancer incidence trends.

Randomized trials of estrogen-alone and breast cancer incidence: a meta-analysis.

PURPOSE: In the Women's Health initiative (WHI) randomized clinical trial, conjugated equine estrogen (CEE)-alone significantly reduced breast cancer incidence (P = 0.005). As cohort studies had opposite findings, other randomized clinical trials were identified to conduct a meta-analysis of estrogen-alone influence on breast cancer incidence. METHODS: We conducted literature searches on randomized trials and: estrogen, hormone therapy, and breast cancer, and searches from a prior meta-analysis and reviews. In the meta-analysis, for trials with published relative risks (RR) and 95% confidence intervals (CI), each log-RR was multiplied by weight = 1/V, where V = variance of the log-RR, and V was derived from the corresponding 95% CI. For smaller trials with only breast cancer numbers, the corresponding log-RR = (O - E)/weight, where O is the observed case number in the oestrogen-alone group and E the corresponding expected case number, E = nP. RESULTS: Findings from 10 randomized trials included 14,282 participants and 591 incident breast cancers. In 9 smaller trials, with 1.2% (24 of 2029) vs 2.2% (33 of 1514) randomized to estrogen-alone vs placebo (open label, one trial) (RR 0.65 95% CI 0.38-1.11, P = 0.12). For 5 trials evaluating estradiol formulations, RR = 0.63 95% CI 0.34-1.16, P = 0.15. Combining the 10 trials, 3.6% (262 of 7339) vs 4.7% (329 of 6943) randomized to estrogen-alone vs placebo (overall RR 0.77 95% CI 0.65-0.91, P = 0.002). CONCLUSION: The totality of randomized clinical trial evidence supports a conclusion that estrogen-alone use significantly reduces breast cancer incidence.

Ductal carcinoma in situ and cause-specific mortality among younger and older postmenopausal women: the Women's Health Initiative.

BACKGROUND: Whether DCIS is associated with higher breast cancer-specific and all-cause mortality is unclear with few studies in older women. Therefore, we examined DCIS and breast cancer-specific, cardiovascular (CVD)-specific, and all-cause mortality among Women's Health Initiative (WHI) Clinical Trial participants overall and by age (< 70 versus ≥ 70 years). METHODS: Of 68,132 WHI participants, included were 781 postmenopausal women with incident DCIS and 781 matched controls. Serial screening mammography was mandated with high adherence. DCIS cases were confirmed by central medical record review. Adjusted multivariable Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI). Kaplan Meier (KM) plots were used to assess 10-year and 20-year mortality rates. RESULTS: After 20.3 years total, and 13.2 years median post-diagnosis follow-up, compared to controls, DCIS was associated with higher breast cancer-specific mortality (HR 3.29; CI = 1.32-8.22, P = 0.01). The absolute difference in 20-year breast cancer mortality was 1.2% without DCIS and 3.4% after DCIS, log-rank P = 0.026. Findings were similar by age (< 70 versus ≥ 70 years) with no interaction (P interaction = 0.80). Incident DCIS was not associated with CVD-specific mortality (HR 0.77; CI-0.54-1.09, P = 0.14) or with all-cause mortality (HR 0.96; CI = 0.80-1.16, P = 0.68) with similar findings by age. CONCLUSIONS: In postmenopausal women, incident DCIS was associated with over three-fold higher breast cancer-specific mortality, with similar findings in younger and older postmenopausal women. These finding suggest caution in using age to adjust DCIS clinical management or research strategies.

The Women's Health Initiative Randomized Trials and Clinical Practice: A Review.

Importance: Approximately 55 million people in the US and approximately 1.1 billion people worldwide are postmenopausal women. To inform clinical practice about the health effects of menopausal hormone therapy, calcium plus vitamin D supplementation, and a low-fat dietary pattern, the Women's Health Initiative (WHI) enrolled 161 808 postmenopausal US women (N = 68 132 in the clinical trials) aged 50 to 79 years at baseline from 1993 to 1998, and followed them up for up to 20 years. Observations: The WHI clinical trial results do not support hormone therapy with oral conjugated equine estrogens plus medroxyprogesterone acetate for postmenopausal women or conjugated equine estrogens alone for those with prior hysterectomy to prevent cardiovascular disease, dementia, or other chronic diseases. However, hormone therapy is effective for treating moderate to severe vasomotor and other menopausal symptoms. These benefits of hormone therapy in early menopause, combined with lower rates of adverse effects of hormone therapy in early compared with later menopause, support initiation of hormone therapy before age 60 years for women without contraindications to hormone therapy who have bothersome menopausal symptoms. The WHI results do not support routinely recommending calcium plus vitamin D supplementation for fracture prevention in all postmenopausal women. However, calcium and vitamin D are appropriate for women who do not meet national guidelines for recommended intakes of these nutrients through diet. A low-fat dietary pattern with increased fruit, vegetable, and grain consumption did not prevent the primary outcomes of breast or colorectal cancer but was associated with lower rates of the secondary outcome of breast cancer mortality during long-term follow-up. Conclusions and Relevance: For postmenopausal women, the WHI randomized clinical trials do not support menopausal hormone therapy to prevent cardiovascular disease or other chronic diseases. Menopausal hormone therapy is appropriate to treat bothersome vasomotor symptoms among women in early menopause, without contraindications, who are interested in taking hormone therapy. The WHI evidence does not support routine supplementation with calcium plus vitamin D for menopausal women to prevent fractures or a low-fat diet with increased fruits, vegetables, and grains to prevent breast or colorectal cancer. A potential role of a low-fat dietary pattern in reducing breast cancer mortality, a secondary outcome, warrants further study.

Frequency of Consuming Breakfast Meals and After-Dinner Snacks Is not Associated with Postmenopausal Breast Cancer Risk: Women's Health Initiative Observational Study.

BACKGROUND: There has been little investigation into how the timing of meals and eating occasions associates with postmenopausal breast cancer risk. OBJECTIVE: We examined the association between the frequency of consuming breakfast meals and after-dinner snacks with the risk for postmenopausal breast cancer. METHODS: A prospective analysis of 74,825 postmenopausal women aged 49 to 81 y from the Women's Health Initiative Observational Study cohort. Breakfast and after-dinner snack intake were assessed at year 1 examination. Risk for invasive and in situ breast cancer diagnosed before 28 February 2020 was modeled with multivariable Cox proportional hazards regression models according to breakfast and after-dinner snack consumption frequencies. The models were adjusted for age, self-identified race/ethnicity, education, income, physical activity, smoking, alcohol intake, diet quality score (Healthy Eating Index 2015), energy intake, diabetic status, hormone therapy, and BMI. RESULTS: During the follow-up period, 5313 participants were diagnosed with invasive breast cancer and 1197 participants with in situ breast cancer. Compared with participants who did not eat breakfast, those with daily breakfast consumption was not associated with invasive breast cancer (HR: 1.04; 95% CI: 0.9, 1.19) nor in situ (HR: 1.25; 95% CI: 0.91, 1.74) breast cancer. There were monotonic higher point estimates of in situ breast cancer for each higher category of breakfast intake from 0 to 7 times per week (P-trend = 0.04, Wald test). Compared with consumption of daily after-dinner snacks, avoidance of after-dinner snacks was not associated with invasive breast cancer (HR: 0.97; 95% CI: 0.87, 1.08) nor in situ (HR: 1.12; 95% CI: 0.89, 1.42) breast cancer. CONCLUSIONS: There was no association between intake frequency of breakfast meals or after-dinner snack habits and with risk of breast cancer in postmenopausal women.

Metabolomics-Based Biomarker for Dietary Fat and Associations with Chronic Disease Risk in Postmenopausal Women.

BACKGROUND: The Women's Health Initiative (WHI) randomized, controlled Dietary Modification (DM) trial of a low-fat dietary pattern suggested intervention benefits related to breast cancer, coronary heart disease (CHD), and diabetes. Here, we use WHI observational data for further insight into the chronic disease implications of adopting this type of low-fat dietary pattern. OBJECTIVES: We aimed to use our earlier work on metabolomics-based biomarkers of carbohydrate and protein to develop a fat intake biomarker by subtraction, to use the resulting biomarker to develop calibration equations that adjusts self-reported fat intake for measurement error, and to study associations of biomarker-calibrated fat intake with chronic disease risk in WHI cohorts. Corresponding studies for specific fatty acids will follow separately. METHODS: Prospective disease association results are presented using WHI cohorts of postmenopausal women, aged 50-79 y when enrolled at 40 United States clinical centers. Biomarker equations were developed using an embedded human feeding study (n = 153). Calibration equations were developed using a WHI nutritional biomarker study (n = 436). Calibrated intakes were associated with cancer, cardiovascular diseases, and diabetes incidence in WHI cohorts (n = 81,954) over an approximate 20-y follow-up period. RESULTS: A biomarker for fat density was developed by subtracting protein, carbohydrate, and alcohol densities from one. A calibration equation was developed for fat density. Hazard ratios (95% confidence intervals) for 20% higher fat density were 1.16 (1.06, 1.27) for breast cancer, 1.13 (1.02, 1.26) for CHD, and 1.19 (1.13, 1.26) for diabetes, in substantial agreement with findings from the DM trial. With control for additional dietary variables, especially fiber, fat density was no longer associated with CHD, with hazard ratio (95% confidence interval) of 1.00 (0.88, 1.13), whereas that for breast cancer was 1.11 (1.00, 1.24). CONCLUSIONS: WHI observational data support prior DM trial findings of low-fat dietary pattern benefits in this population of postmenopausal United States women. TRIAL REGISTRATION NUMBER: This study is registered with clinicaltrials.gov identifier: NCT00000611.

Metabolomics Biomarkers for Fatty Acid Intake and Biomarker-Calibrated Fatty Acid Associations with Chronic Disease Risk in Postmenopausal Women.

BACKGROUND: A substantial observational literature relating specific fatty acid classes to chronic disease risk may be limited by its reliance on self-reported dietary data. OBJECTIVES: We aimed to develop biomarkers for saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acid densities, and to study their associations with cardiovascular disease (CVD), cancer, and type 2 diabetes (T2D) in Women's Health Initiative (WHI) cohorts. METHODS: Biomarker equations were based primarily on serum and urine metabolomics profiles from an embedded WHI human feeding study (n = 153). Calibration equations were based on biomarker values in a WHI nutritional biomarker study (n = 436). Calibrated intakes were assessed in relation to disease incidence in larger WHI cohorts (n = 81,894). Participants were postmenopausal women, aged 50-79 when enrolled at 40 United States Clinical Centers (1993-1998), with a follow-up period of ∼20 y. RESULTS: Biomarker equations meeting criteria were developed for SFA, MUFA, and PUFA densities. That for SFA density depended somewhat weakly on metabolite profiles. On the basis of our metabolomics platforms, biomarkers were insensitive to trans fatty acid intake. Calibration equations meeting criteria were developed for SFA and PUFA density, but not for MUFA density. With or without biomarker calibration, SFA density was associated positively with risk of CVD, cancer, and T2D, but with small hazard ratios, and CVD associations were not statistically significant after controlling for other dietary variables, including trans fatty acid and fiber intake. Following this same control, PUFA density was not significantly associated with CVD risk, but there were positive associations for some cancers and T2D, with or without biomarker calibration. CONCLUSIONS: Higher SFA and PUFA diets were associated with null or somewhat higher risk for clinical outcomes considered in this population of postmenopausal United States women. Further research is needed to develop even stronger biomarkers for these fatty acid densities and their major components. This study is registered with clinicaltrials.gov identifier: NCT00000611.

Calcium Intake and Lung Cancer Risk: A Pooled Analysis of 12 Prospective Cohort Studies.

BACKGROUND: Previous studies on calcium intake and lung cancer risk reported inconsistent associations, possibly due to the differences in intake amounts and contributing sources of calcium and smoking prevalence. OBJECTIVES: We investigated the associations of lung cancer risk with intake of calcium from foods and/or supplements and major calcium-rich foods in 12 studies. METHODS: Data from 12 prospective cohort studies conducted in the United States, Europe, and Asia were pooled and harmonized. We applied the DRI to categorize calcium intake based on the recommendations and quintile distribution to categorize calcium-rich food intake. We ran multivariable Cox regression by each cohort and pooled risk estimates to compute overall HR (95% CI). RESULTS: Among 1,624,244 adult men and women, 21,513 incident lung cancer cases were ascertained during a mean follow-up of 9.9 y. Overall, the dietary calcium intake was not significantly associated with lung cancer risk; the HRs (95% CI) were 1.08 (0.98-1.18) for higher (>1.5 RDA) and 1.01 (0.95-1.07) for lower intake (<0.5 RDA) comparing with recommended intake (EAR to RDA). Milk and soy food intake were positively or inversely associated with lung cancer risk [HR (95% CI) = 1.07 (1.02-1.12) and 0.92 (0.84-1.00)], respectively. The positive association with milk intake was significant only in European and North American studies (P-interaction for region = 0.04). No significant association was observed for calcium supplements. CONCLUSIONS: In this largest prospective investigation, overall, calcium intake was not associated with risk of lung cancer, but milk intake was associated with a higher risk. Our findings underscore the importance of considering food sources of calcium in studies of calcium intake.

Predicting All-Cause Mortality in Women With and Without Breast Cancer Using the Schonberg Index: A Women's Health Initiative Study.

BACKGROUND: When treating older women with breast cancer, life expectancy is an important consideration. ASCO recommends calculating 10-year mortality probabilities to inform treatment decisions. One useful tool is the Schonberg index, which predicts risk-based all-cause 10-year mortality. We investigated the use of this index in women aged ≥65 years with breast cancer in the Women's Health Initiative (WHI). METHODS: We calculated 10-year mortality risk scores for 2,549 WHI participants with breast cancer ("cases") and 2,549 age-matched breast cancer-free participants ("controls") using Schonberg index risk scoring. Risk scores were grouped into quintiles for comparisons. Risk-stratified observed mortality rates and 95% confidence intervals were compared across cases and controls. Observed 10-year mortality rates in cases and controls were also compared with Schonberg index-based predicted 10-year mortality rates. RESULTS: Compared with controls, cases were more often white (P=.005), had higher income and education levels (P<.001 for both), more often lived with their husband/partner (P<.001), scored higher on subjective health/happiness (P<.001), and needed less assistance in activities of daily living (P<.001). Participants with breast cancer had similar risk-stratified 10-year mortality rates compared with controls (34% vs 33%, respectively). Stratified results showed that cases had slightly higher mortality rates than controls in the lowest risk quintile and lower mortality rates in the 2 highest risk quintiles. Observed mortality rates in cases and controls were similar to Schonberg index-predicted mortality, with model c-indexes of 0.71 and 0.76, respectively. CONCLUSIONS: Among women aged ≥65 years with incident breast cancer, the Schonberg index-based risk-stratified 10-year mortality rates were similar to those in women without breast cancer, demonstrating a similar performance of the index among both populations. Along with other health measures, prognostic indexes can help predict survival among older women with breast cancer and support geriatric oncology guidelines that promote using life expectancy calculation tools for shared decision-making.

The relationship between optimism, MCI, and dementia among postmenopausal women.

OBJECTIVES: The relationship between optimism and cognitive functioning is not fully understood. We examined the association of optimism with risk of mild cognitive impairment (MCI) and dementia in the Women's Health Initiative Memory Study (WHIMS). METHODS: Optimism was measured by the Life Orientation Test-Revised (LOT-R) total score, and optimism and pessimism subscales. A panel of experts adjudicated cognitive endpoints based on annual cognitive assessments. We used cox proportional hazard regression models to examine the association of LOT-R total score and optimism and pessimism sub-scores with MCI/dementia. We also examined the relationship between vascular disease, LOT-R total score, optimism and pessimism, and cognition. RESULTS: Mean age was 70.5 (SD = 3.9) years. The sample (N = 7249) was 87% white, and 29.8% of participants had < 12 years of education. Total LOT-R score (HR = 0.96, 95% CI: 0.94, 0.98, p < 0.001) was associated with lower risk of combined MCI or dementia. More pessimism (HR = 1.08, 95% CI: 1.05, 1.11, p < 0.0001) was associated with higher risk of MCI or dementia after adjustment for ethnicity, education, vascular disease, and depression. No significant relationships emerged from the optimism subscale. CONCLUSION: These data suggest that less pessimism, but not more optimism, was associated with a lower risk of MCI and dementia.

A Coala-T-Cannabis Survey Study of breast cancer patients' use of cannabis before, during, and after treatment.

BACKGROUND: The goal of this study was to characterize cannabis use among patients with breast cancer, including their reasons for and timing of use, their sources of cannabis information and products, their satisfaction with the information found, their perceptions of its safety, and their dialogue about cannabis with their physicians. METHODS: United States-based members of the Breastcancer.org and Healthline.com communities with a self-reported diagnosis of breast cancer within 5 years (age ≥ 18 years) were invited to participate in an anonymous online survey. After informed consent was obtained, nonidentifiable data were collected and analyzed. RESULTS: Of all participants (n = 612), 42% (n = 257) reported using cannabis for relief of symptoms, which included pain (78%), insomnia (70%), anxiety (57%), stress (51%), and nausea/vomiting (46%). Furthermore, 49% of cannabis users believed that medical cannabis could be used to treat cancer itself. Of those taking cannabis, 79% had used it during treatment, which included systemic therapies, radiation, and surgery. At the same time, few (39%) had discussed it with any of their physicians. CONCLUSIONS: A significant percentage of survey participants (42%) used cannabis to address symptoms; approximately half of these participants believed that cannabis could treat cancer itself. Most participants used cannabis during active cancer treatment despite the potential for an adverse event during this vulnerable time. Furthermore, most participants believed that cannabis was safe and were unaware that product quality varied widely and depended on the source. This study reviews the research on medicinal cannabis in the setting of these findings to help physicians to recognize its risks and benefits for patients with cancer. LAY SUMMARY: Almost half of patients with breast cancer use cannabis, most commonly during active treatment to manage common symptoms and side effects: pain, anxiety, insomnia, and nausea. However, most patients do not discuss cannabis use with their physicians. Instead, the internet and family/friends are the most common sources of cannabis information. Furthermore, most participants believe that cannabis products are safe and are unaware that the safety of many products is untested.

Adherence to the American Cancer Society Guidelines on nutrition and physical activity for cancer prevention and obesity-related cancer risk and mortality in Black and Latina Women's Health Initiative participants.

BACKGROUND: Although adherence to the American Cancer Society (ACS) Guidelines on Nutrition and Physical Activity for Cancer Prevention associates with lower risk of obesity-related cancer (ORC) incidence and mortality, evidence in Black and Latina women is limited. This association was examined in Black and Latina participants in the Women's Health Initiative (WHI). METHODS: Semi-Markov multistate model examined the association between ACS guideline adherence and ORC incidence and mortality in the presence of competing events, combined and separately, for 9301 Black and 4221 Latina postmenopausal women. Additionally, ACS guideline adherence was examined in a subset of less common ORCs and potential effect modification by neighborhood socioeconomic status and smoking. RESULTS: Over a median of 11.1, 12.5, and 3.7 years of follow-up for incidence, nonconditional mortality, and conditional mortality, respectively, 1191 ORCs (Black/Latina women: 841/269), 1970 all-cause deaths (Black/Latina women: 1576/394), and 341 ORC-related deaths (Black/Latina women: 259/82) were observed. Higher ACS guideline adherence was associated with lower ORC incidence for both Black (cause-specific hazard ratio [CSHR]highvs.low : 0.72; 95% CI, 0.55-0.94) and Latina (CSHRhighvs.low : 0.58, 95% CI, 0.36-0.93) women; but not conditional all-cause mortality (Black hazard ratio [HR]highvs.low : 0.86; 95% CI, 0.53-1.39; Latina HRhighvs.low : 0.81; 95% CI, 0.32-2.06). Higher adherence was associated with lower incidence of less common ORC (Ptrend  = .025), but conditional mortality events were limited. Adherence and ORC-specific deaths were not associated and there was no evidence of effect modification. CONCLUSIONS: Adherence to the ACS guidelines was associated with lower risk of ORCs and less common ORCs but was not for conditional ORC-related mortality. LAY SUMMARY: Evidence on the association between the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and cancer remains scarce for women of color. Adherence to the guidelines and risk of developing one of 13 obesity-related cancers among Black and Latina women in the Women's Health Initiative was examined. Women who followed the lifestyle guidelines had 28% to 42% lower risk of obesity-related cancer. These findings support public health interventions to reduce growing racial/ethnic disparities in obesity-related cancers.

Polygenic Risk Scores for Prediction of Breast Cancer and Breast Cancer Subtypes.

Stratification of women according to their risk of breast cancer based on polygenic risk scores (PRSs) could improve screening and prevention strategies. Our aim was to develop PRSs, optimized for prediction of estrogen receptor (ER)-specific disease, from the largest available genome-wide association dataset and to empirically validate the PRSs in prospective studies. The development dataset comprised 94,075 case subjects and 75,017 control subjects of European ancestry from 69 studies, divided into training and validation sets. Samples were genotyped using genome-wide arrays, and single-nucleotide polymorphisms (SNPs) were selected by stepwise regression or lasso penalized regression. The best performing PRSs were validated in an independent test set comprising 11,428 case subjects and 18,323 control subjects from 10 prospective studies and 190,040 women from UK Biobank (3,215 incident breast cancers). For the best PRSs (313 SNPs), the odds ratio for overall disease per 1 standard deviation in ten prospective studies was 1.61 (95%CI: 1.57-1.65) with area under receiver-operator curve (AUC) = 0.630 (95%CI: 0.628-0.651). The lifetime risk of overall breast cancer in the top centile of the PRSs was 32.6%. Compared with women in the middle quintile, those in the highest 1% of risk had 4.37- and 2.78-fold risks, and those in the lowest 1% of risk had 0.16- and 0.27-fold risks, of developing ER-positive and ER-negative disease, respectively. Goodness-of-fit tests indicated that this PRS was well calibrated and predicts disease risk accurately in the tails of the distribution. This PRS is a powerful and reliable predictor of breast cancer risk that may improve breast cancer prevention programs.

Long-term dietary intervention influence on physical activity in the Women's Health Initiative Dietary Modification randomized trial.

PURPOSE: In the Women's Health Initiative (WHI) Dietary Modification (DM) randomized trial, dietary intervention significantly reduced breast cancer mortality (P = 0.02). In observational studies, physical activity is associated with lower breast cancer incidence. Currently, dietary intervention influence on other health-related behaviors is unknown. Therefore, we evaluated whether the WHI dietary intervention influenced self-directed physical activity. METHODS: Of 48,835 postmenopausal women, 19,541 were randomized to dietary intervention (18 nutritionist-led group sessions first year, then quarterly sessions throughout 8.5 years [median] intervention) and 29,294 to a usual diet comparison (written health-related materials only). Neither randomization group received specific or ongoing instructions to increase physical activity. Episodes per week of moderate or vigorous recreational physical activity (MVPA) were serially reported. Marginal longitudinal logistic regression models were used to assess physically inactive (MVPA = 0) or physically active (MVPA > 0) participants by randomization group. Marginal Poisson regression models estimated mean weekly MVPA. RESULTS: At entry, 45.6% of all participants reported physical inactivity (MVPA = 0). In 43,760 women with MVPA information, throughout 15.9 years (median) cumulative follow-up, dietary intervention group participation was associated with 7% lower physical inactivity rate (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.91, 0.95, P < 0.001) and a 4% higher mean MVPA (ratio of means [RM] 1.04 95% CI 1.02, 1.06, P < 0.001), relative to the comparison group. CONCLUSION: In a randomized trial setting, a low-fat dietary pattern intervention was associated with a long-term, favorable influence on self-directed recreational physical activity. TRIAL REGISTRATION: NCT00000611.

Racial differences in anthropometric measures as risk factors for triple-negative breast cancer.

PURPOSE: The incidence of triple-negative breast cancer (TNBC) is higher in Black women compared to White women which is not explained by racial differences in body mass index (BMI). As BMI has limitations as an anthropometric measure, we used different anthropometric measures to examine associations with TNBC by race. METHOD: Of 161,808 postmenopausal participants in Women's Health Initiative, eligible were a subsample of 121,744 White and Black postmenopausal women enrolled from 1993 to 1998, 50-79 years of age with anthropometric measures who were followed for breast cancer incidence until March 2019. At entry, BMI, waist circumference (WC), and waist-hip ratio (WHR) were measured using standardized methods. Breast cancers were verified by central medical record review. Associations between anthropometric measures and triple-negative breast cancer risk were examined using Cox proportional hazards regression models. RESULTS: After 17.6 years (median) follow-up, there were 87 Black women and 529 White women with incident triple-negative breast cancer. Overall, there were no significant associations between anthropometric measures and risk of triple-negative breast cancer. However, compared to White women with normal BMI, White women with obesity (BMI ≥ 30) (HR 0.76, 95% CI 0.60, 0.96) were significantly associated with a lower risk of triple-negative breast cancer. And larger waist circumference (HR per centimeter 0.99, 95% CI 0.99, 1.00) was significantly associated with a lower risk of triple-negative breast cancer among White women. CONCLUSION: Overall, among postmenopausal women, anthropometric measures were not associated with risk of TNBC. The association among White women with larger waist circumference and women with obesity with a lower risk of triple-negative breast cancer needs further confirmation.

MRI Based Validation of Abdominal Adipose Tissue Measurements From DXA in Postmenopausal Women.

INTRODUCTION: Visceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI. METHODOLOGY: Participants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed. RESULTS: Participants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500. CONCLUSIONS: New software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.

Cardiometabolic risk factors, physical activity, and postmenopausal breast cancer mortality: results from the Women's Health Initiative.

BACKGROUND: Higher physical activity levels are associated with lower breast cancer-specific mortality. In addition, the metabolic syndrome is associated with higher breast cancer-specific mortality. Whether the physical activity association with breast cancer mortality is modified by number of metabolic syndrome components (cardiometabolic risk factors) in postmenopausal women with early-stage breast cancer remains unknown. METHODS: Cardiovascular risk factors included high waist circumference, hypertension, high cholesterol, and diabetes. Breast cancers were verified by medical record review. Mortality finding were enhanced by serial National Death Index queries. Cox proportional hazards regression models were used to estimate associations between baseline physical activity and subsequent breast cancer-specific and overall mortality following breast cancer diagnosis in Women's Health Initiative participants. These associations were examined after stratifying by cardiometabolic risk factor group. RESULTS: Among 161,308 Women's Health Initiative (WHI) participants, 8543 breast cancers occurred after 9.5 years (median) follow-up in women, additionally with information on cardiometabolic risk factors and physical activity at entry. In multi-variable analyses, as measured from cancer diagnosis, higher physical activity levels were associated with lower all-cause mortality risk (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.78-0.95, trend P < 0.001) but not with breast cancer-specific mortality (HR 0.85, 95% CI 0.70 to 1.04, trend P = 0.09). The physical activity and all-cause mortality association was not significantly modified by cardiometabolic risk factor number. CONCLUSIONS: Among women with early-stage breast cancer, although higher antecedent physical activity was associated with lower risk of all-cause mortality, the association did not differ by cardiometabolic risk factor number.

Randomized Trial Evaluation of the Benefits and Risks of Menopausal Hormone Therapy Among Women 50-59 Years of Age.

The health benefits and risks of menopausal hormone therapy among women aged 50-59 years are examined in the Women's Health Initiative randomized, placebo-controlled trials using long-term follow-up data and a parsimonious statistical model that leverages data from older participants to increase precision. These trials enrolled 27,347 healthy postmenopausal women aged 50-79 years at 40 US clinical centers during 1993-1998, including 10,739 post-hysterectomy participants in a trial of conjugated equine estrogens and 16,608 participants with a uterus in the trial of these estrogens plus medroxyprogesterone acetate. Over a (median) 18-year follow-up period (1993-2016), risk for a global index (defined as the earliest of coronary heart disease, invasive breast cancer, stroke, pulmonary embolism, colorectal cancer, endometrial cancer, hip fracture, and all-cause mortality) was reduced with conjugated equine estrogens with a hazard ratio of 0.82 (95% confidence interval: 0.71, 0.95), and with nominally significant reductions for coronary heart disease, breast cancer, hip fracture, and all-cause mortality. Corresponding global index hazard ratio estimates of 1.06 (95% confidence interval: 0.95, 1.19) were nonsignificant for combined estrogens plus progestin, but increased breast cancer risk and reduced endometrial cancer risk were observed. These results, among women 50-59 years of age, substantially agree with the worldwide observational literature, with the exception of breast cancer for estrogens alone.

Metabolic syndrome risk components and mortality after triple-negative breast cancer diagnosis in postmenopausal women in the Women's Health Initiative.

BACKGROUND: Triple-negative breast cancer (TNBC) has a high recurrence risk and poor clinical outcomes. Associations between metabolic syndrome (MetS) risk components and mortality in postmenopausal women with TNBC were examined in the Women's Health Initiative. METHODS: Five hundred forty-four postmenopausal women were diagnosed with nonmetastatic TNBC. Baseline risk components included a high waist circumference (≥88 cm), high blood pressure, hypercholesterolemia, and diabetes. Groups were categorized by the number of MetS risk components: none, 1 or 2, or 3 or 4. Hazard ratios (HRs) and 95% confidence intervals (CIs) across groups were computed with multivariable adjusted Cox models. Outcomes included breast cancer-specific mortality and breast cancer overall mortality (breast cancer followed by death from any cause). Variables in the multivariable model included age at TNBC diagnosis; race/ethnicity; income; education; clinical/observational trial status; history of oral contraceptive, hormone, and/or statin use; cancer stage; and chemotherapy and/or radiation treatment status. RESULTS: Of the 544 participants with TNBC, 33% had no MetS risk components (n = 178), 59% had 1 or 2 risk components (n = 323), and 8% had 3 or 4 risk components (n = 43). After a median follow-up from diagnosis of 8.3 years, multivariable results showed that women with 3 or 4 risk components had a nonsignificantly higher risk of breast cancer mortality (HR, 2.05; 95% CI, 0.94-4.47 trend P = .114) and a significantly higher risk of overall mortality (HR, 2.13; 95% CI, 1.22-3.71; trend P = .006) versus women with 0 risk components. CONCLUSIONS: Postmenopausal women with TNBC and 3 or 4 MetS risk components have a nonsignificantly higher breast cancer mortality risk and a significantly higher overall mortality risk, likely because of negative influences of metabolic risk factors on several causes of death.