A review of research on the intersection between breast cancer and cardiovascular research in the Women’s Health Initiative (WHI)

Both obesity and metabolic syndrome are linked to increased incidence of type 2 diabetes, cardiovascular disease (CVD), and cancers of the breast (post-menopausal), and other obesity-related cancers. Over the past 50 years, the worldwide prevalence of obesity and metabolic syndrome has increased, with a concomitant higher incidence of associated co-morbidities and mortality. The precise mechanism linking metabolic syndrome to increased cancer incidence is incompletely understood, however, individual components of metabolic syndrome have been linked to increased breast cancer incidence and worse survival. There is a bidirectional relationship between the risk of CVD and cancer due to a high burden of shared risk factors and higher rates of CVD among cancer survivors, which may be impacted by the pro-inflammatory microenvironment associated with metabolic syndrome and cancer-directed therapies. The Women’s Health Initiative (WHI) is an excellent resource to study a dual relationship between cancer and CVD (cardio-oncology) with extensive information on risk factors and long-term outcomes. The purpose of this review is to provide an overview of research on cardio-oncology conducted utilizing WHI data with focus on studies evaluating both breast cancer and CVD including shared risk factors and outcomes after cancer. The review also includes results on other obesity related cancers which were included in the analyses of breast cancer, articles looking at cancer after heart disease (reverse cardio-oncology) and the role of Clonal Hematopoiesis of Indeterminate Potential (CHIP) as a shared risk factor between CVD and cancer. A summary of pertinent WHI literature helps to delineate the direction of future research evaluating the relationship between CVD and other cancer sites, and provides information on the opportunity for other novel analyses within the WHI

The association between heart failure and incident cancer in women: an analysis of the Women's Health Initiative

AimsThere is conflicting evidence whether heart failure (HF) is a risk factor for incident cancer. Despite population-based cohorts demonstrating this association, an analysis of the Physician's Health Study found no association in a cohort of mostly healthy males. We investigated the association of HF with incident cancer among a large cohort of post-menopausal women.Methods and resultsA prospective cohort study of 146 817 post-menopausal women age 50 to 79 years enrolled in the Women's Health Initiative from 1993-1998, and followed through 2015. The primary exposure was adjudicated incident HF diagnosis, including preserved and reduced ejection fraction in a sub-cohort. The primary outcome was adjudicated incident total and site-specific cancers. Hazard ratios were calculated using multivariable-adjusted Cox proportional hazard regression models. Over a median follow-up of 8.4 years, 3272 and 17 474 women developed HF and cancer, respectively. HF developed in 235 women prior to cancer. HF was associated with subsequent incident cancer [hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.11-1.48]. Associations were observed for obesity-related cancers (HR 1.24, 95% CI 1.02-1.51), as well as lung and colorectal cancers (HR 1.58, 95% CI 1.09-2.30 and HR 1.52, 95% CI 1.02-2.27, respectively). HF with preserved ejection fraction (HR 1.34, 95% CI 1.06-1.67), but not HF reduced ejection fraction (HR 0.99, 95% CI 0.74-1.34), was associated with total cancer.ConclusionHeart failure was associated with an increase in cancer diagnoses in post-menopausal women. This association was strongest for lung cancer. Further research is needed to appreciate the underlying mechanisms responsible for this association

Histamine H2 Receptor Antagonists and Heart Failure Risk in Postmenopausal Women: The Women’s Health Initiative

Background Prior studies suggested lower risk of heart failure (HF) in individuals taking H2 receptor antagonists (H2RA) compared with H2RA nonusers in relatively small studies. We evaluated the association of H2RA use and incident HF in postmenopausal women in the large‐scale WHI (Women’s Health Initiative) study. Methods and Results This study included postmenopausal women from the WHI without a history of HF at baseline. HF was defined as first incident hospitalization for HF and physician adjudicated. Multivariable Cox proportional hazards regression models evaluated the association of H2RA use as a time‐varying exposure with HF risk, after adjustment for demographic, lifestyle, and medical history variables. Sensitivity analyses examined (1) risk of HF stratified by the ARIC (Atherosclerosis Risk in Communities) score, (2) propensity score matching on H2RA use, (3) use of proton pump inhibitors rather than H2RA nonuse as the referent, and (4) exclusion of those taking diuretics at baseline. The primary analysis included 158 854 women after exclusion criteria, of whom 9757 (6.1%) were H2RA users. During median 8.2 years of follow‐up, 376 H2RA users (4.9 events/1000 person‐years) and 3206 nonusers (2.7 events/1000 person‐years) developed incident HF. After multivariable adjustment, there was no association between H2RA use and HF in the primary analysis (hazard ratio, 1.07; 95% CI, 0.94–1.22; P=0.31) or in any of the sensitivity analyses. Conclusions Clinical H2RA use was not associated with incident HF among postmenopausal women. Future studies are needed to evaluate potential effect modification by sex, HF severity, or patterns of use on H2RA exposure and HF risk. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00000611

Increased soluble urokinase plasminogen activator levels modulate monocyte function to promote atherosclerosis

People with kidney disease are disproportionately affected by atherosclerosis for unclear reasons. Soluble urokinase plasminogen activator receptor (suPAR) is an immune-derived mediator of kidney disease, levels of which are strongly associated with cardiovascular outcomes. We assessed suPAR’s pathogenic involvement in atherosclerosis using epidemiologic, genetic, and experimental approaches. We found serum suPAR levels to be predictive of coronary artery calcification and cardiovascular events in 5,406 participants without known coronary disease. In a genome-wide association meta-analysis including over 25,000 individuals, we identified a missense variant in the plasminogen activator, urokinase receptor (PLAUR) gene (rs4760), confirmed experimentally to lead to higher suPAR levels. Mendelian randomization analysis in the UK Biobank using rs4760 indicated a causal association between genetically predicted suPAR levels and atherosclerotic phenotypes. In an experimental model of atherosclerosis, proprotein convertase subtilisin/kexin–9 (Pcsk9) transfection in mice overexpressing suPAR (suPARTg) led to substantially increased atherosclerotic plaques with necrotic cores and macrophage infiltration compared with those in WT mice, despite similar cholesterol levels. Prior to induction of atherosclerosis, aortas of suPARTg mice excreted higher levels of CCL2 and had higher monocyte counts compared with WT aortas. Aortic and circulating suPARTg monocytes exhibited a proinflammatory profile and enhanced chemotaxis. These findings characterize suPAR as a pathogenic factor for atherosclerosis acting at least partially through modulation of monocyte function