Cocoa extract is a source of flavanols that favorably influence vascular risk factors in small and short-term trials, yet effects on clinical cardiovascular events are untested.
We examined whether ...cocoa extract supplementation decreases total cardiovascular disease (CVD) among older adults.
We conducted a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial of cocoa extract supplementation and multivitamins for prevention of CVD and cancer among 21,442 US adults (12,666 women aged ≥65 y and 8776 men aged ≥60 y), free of major CVD and recently diagnosed cancer. The intervention phase was June 2015 through December 2020. This article reports on the cocoa extract intervention. Participants were randomly assigned to a cocoa extract supplement 500 mg flavanols/d, including 80 mg (–)-epicatechin or placebo. The primary outcome was a composite of confirmed incident total cardiovascular events, including myocardial infarction (MI), stroke, coronary revascularization, cardiovascular death, carotid artery disease, peripheral artery surgery, and unstable angina.
During a median follow-up of 3.6 y, 410 participants taking cocoa extract and 456 taking placebo had confirmed total cardiovascular events (HR: 0.90; 95% CI: 0.78, 1.02; P = 0.11). For secondary endpoints, HRs were 0.73 (95% CI: 0.54, 0.98) for CVD death, 0.87 (95% CI: 0.66, 1.16) for MI, 0.91 (95% CI: 0.70, 1.17) for stroke, 0.95 (95% CI: 0.77, 1.17) for coronary revascularization, neutral for other individual cardiovascular endpoints, and 0.89 (95% CI: 0.77, 1.03) for all-cause mortality. Per-protocol analyses censoring follow-up at nonadherence supported a lower risk of total cardiovascular events (HR: 0.85; 95% CI: 0.72, 0.99). There were no safety concerns.
Cocoa extract supplementation did not significantly reduce total cardiovascular events among older adults but reduced CVD death by 27%. Potential reductions in total cardiovascular events were supported in per-protocol analyses. Additional research is warranted to clarify whether cocoa extract may reduce clinical cardiovascular events. This trial is registered at www.clinicaltrials.gov as NCT02422745.
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Observational studies have suggested that metformin decreases the incidence of several common cancers. However, findings regarding breast cancer have been mixed. In order to explore this issue, a ...systematic literature review and meta-analysis were performed with a focus on potential biases. We conducted a comprehensive literature search for all pertinent studies addressing metformin use and breast cancer risk by searching PubMed, Cochrane Library, and Scopus (which includes Embase, ISI Web of Science) using the Mesh terms: “metformin” or “biguanides” or “diabetes mellitus, type 2/therapy” and “cancer” or “neoplasms.” When multiple hazard ratios (HR) or odds ratio (OR) were reported, the most adjusted estimate was used in the base-case analysis. We pooled the adjusted HR and performed sensitivity analyses on duration of metformin use (> or ≤3 years use), study quality (assessed using the GRADE system), and initial observation year of the cohort (before vs after 1997). From a total of 443 citations, 18 full-text articles were considered, and seven independent studies were included. All were observational (four cohort and three case control). Our combined OR of all seven studies was 0.83 (0.71–0.97). Stronger associations were found when analyses were limited to studies estimating the impact of longer metformin use (OR = 0.75. 95 % CI 0.62, 0.91) or among studies that began observing their cohort before 1997 (OR = 0.68. 95 % CI 0.55–0.084). Stratification according to study quality did not affect the combined OR but higher quality studies had smaller CI and achieved statistical significance. Interpretation is limited by the observational nature of reports and different comparison groups. Our analyses support a protective effect of metformin on breast cancer risk among postmenopausal women with diabetes. Clinical trials are needed for definitive determination of the role of metformin in breast cancer risk reduction.
The menopausal hormone therapy (MHT) association with breast cancer has been controversial for more than 40 years. Most recently, findings from cohort studies have been discordant compared with those ...from the Women's Health Initiative (WHI) randomized trials. In cohort studies, both estrogen therapy and estrogen plus progestin were associated with higher breast cancer incidence. In contrast, in the WHI randomized trials, findings for estrogen plus progestin are concordant with cohort study reports, whereas estrogen therapy significantly reduced breast cancer incidence. In addition, concerns have been raised regarding the WHI findings from both trials. In this report, we briefly summarize findings for MHT on breast cancer from cohort studies and the WHI randomized trials. The report focus is addressing, point-by-point, concerns raised regarding the WHI findings.
For cohort studies, we relied on the latest findings from (1) the meta-analysis of the Collaborative Group on Hormonal Factors in Breast Cancer and (2) the Million Women's Study. To identify commentaries and editorials, "Menopause" and "Climacteric" were searched from 2002 to present; PubMed and Google Scholar were searched for commentaries, editorials, and breast cancer, MHT, estrogen, conjugated equine estrogen, estradiol, "hormone replacement therapy," and "HRT."
Thirty commentaries challenging WHI findings were identified. All were reviewed, and issues needing response were identified. Findings from the meta-analysis from the Collaborative Group on Hormonal Factors in Breast Cancer and the Million Women Study were summarized and compared with finding in the two WHI randomized trials evaluating estrogen therapy and estrogen plus progestin. Based on the randomized clinical trials, estrogen therapy, for women with prior hysterectomy, decreases breast cancer incidence and mortality. In contrast, estrogen plus progestin increases breast cancer incidence, which persists through two decades. Women considering estrogen plus progestin use for vasomotor symptoms should understand the breast cancer risk.
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.
Summary Background By contrast with many observational studies, women in the Women's Health Initiative (WHI) trial who were randomly allocated to receive oestrogen alone had a lower incidence of ...invasive breast cancer than did those who received placebo. We aimed to assess the influence of oestrogen use on longer term breast cancer incidence and mortality in extended follow-up of this cohort. Methods Between 1993 and 1998, the WHI enrolled 10 739 postmenopausal women from 40 US clinical centres into a randomised, double-masked, placebo-controlled trial. Women aged 50–79 years who had undergone hysterectomy and had expected 3-year survival and mammography clearance were randomly allocated by a computerised, permuted block algorithm, stratified by age group and centre, to receive oral conjugated equine oestrogen (0·625 mg per day; n=5310) or matched placebo (n=5429). The trial intervention was terminated early on Feb 29, 2004, because of an adverse effect on stroke. Follow-up continued until planned termination (March 31, 2005). Consent was sought for extended surveillance from the 9786 living participants in active follow-up, of whom 7645 agreed. Using data from this extended follow-up (to Aug 14, 2009), we assessed long-term effects of oestrogen use on invasive breast cancer incidence, tumour characteristics, and mortality. We used Cox regression models to estimate hazard ratios (HRs) in the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT00000611. Findings After a median follow-up of 11·8 years (IQR 9·1–12·9), the use of oestrogen for a median of 5·9 years (2·5–7·3) was associated with lower incidence of invasive breast cancer (151 cases, 0·27% per year) compared with placebo (199 cases, 0·35% per year; HR 0·77, 95% CI 0·62–0·95; p=0·02) with no difference (p=0·76) between intervention phase (0·79, 0·61–1·02) and post-intervention phase effects (0·75, 0·51–1·09). In subgroup analyses, we noted breast cancer risk reduction with oestrogen use was concentrated in women without benign breast disease (p=0·01) or a family history of breast cancer (p=0·02). In the oestrogen group, fewer women died from breast cancer (six deaths, 0·009% per year) compared with controls (16 deaths, 0·024% per year; HR 0·37, 95% CI 0·13–0·91; p=0·03). Fewer women in the oestrogen group died from any cause after a breast cancer diagnosis (30 deaths, 0·046% per year) than did controls (50 deaths, 0·076%; HR 0·62, 95% CI 0·39–0·97; p=0·04). Interpretation Our findings provide reassurance for women with hysterectomy seeking relief of climacteric symptoms in terms of the effects of oestrogen use for about 5 years on breast cancer incidence and mortality. However, our data do not support use of oestrogen for breast cancer risk reduction because any noted benefit probably does not apply to populations at increased risk of such cancer. Funding US National Heart, Lung, and Blood Institute; Wyeth.
IMPORTANCE: The influence of menopausal hormone therapy on breast cancer remains unsettled with discordant findings from observational studies and randomized clinical trials. OBJECTIVE: To assess the ...association of prior randomized use of estrogen plus progestin or prior randomized use of estrogen alone with breast cancer incidence and mortality in the Women’s Health Initiative clinical trials. DESIGN, SETTING, AND PARTICIPANTS: Long-term follow-up of 2 placebo-controlled randomized clinical trials that involved 27 347 postmenopausal women aged 50 through 79 years with no prior breast cancer and negative baseline screening mammogram. Women were enrolled at 40 US centers from 1993 to 1998 with follow-up through December 31, 2017. INTERVENTIONS: In the trial involving 16 608 women with a uterus, 8506 were randomized to receive 0.625 mg/d of conjugated equine estrogen (CEE) plus 2.5 mg/d of medroxyprogesterone acetate (MPA) and 8102, placebo. In the trial involving 10 739 women with prior hysterectomy, 5310 were randomized to receive 0.625 mg/d of CEE alone and 5429, placebo. The CEE-plus-MPA trial was stopped in 2002 after 5.6 years’ median intervention duration, and the CEE-only trial was stopped in 2004 after 7.2 years’ median intervention duration. MAIN OUTCOMES AND MEASURES: The primary outcome was breast cancer incidence (protocol prespecified primary monitoring outcome for harm) and secondary outcomes were deaths from breast cancer and deaths after breast cancer. RESULTS: Among 27 347 postmenopausal women who were randomized in both trials (baseline mean SD age, 63.4 years 7.2 years), after more than 20 years of median cumulative follow-up, mortality information was available for more than 98%. CEE alone compared with placebo among 10 739 women with a prior hysterectomy was associated with statistically significantly lower breast cancer incidence with 238 cases (annualized rate, 0.30%) vs 296 cases (annualized rate, 0.37%; hazard ratio HR, 0.78; 95% CI, 0.65-0.93; P = .005) and was associated with statistically significantly lower breast cancer mortality with 30 deaths (annualized mortality rate, 0.031%) vs 46 deaths (annualized mortality rate, 0.046%; HR, 0.60; 95% CI, 0.37-0.97; P = .04). In contrast, CEE plus MPA compared with placebo among 16 608 women with a uterus was associated with statistically significantly higher breast cancer incidence with 584 cases (annualized rate, 0.45%) vs 447 cases (annualized rate, 0.36%; HR, 1.28; 95% CI, 1.13-1.45; P < .001) and no significant difference in breast cancer mortality with 71 deaths (annualized mortality rate, 0.045%) vs 53 deaths (annualized mortality rate, 0.035%; HR, 1.35; 95% CI, 0.94-1.95; P= .11). CONCLUSIONS AND RELEVANCE: In this long-term follow-up study of 2 randomized trials, prior randomized use of CEE alone, compared with placebo, among women who had a previous hysterectomy, was significantly associated with lower breast cancer incidence and lower breast cancer mortality, whereas prior randomized use of CEE plus MPA, compared with placebo, among women who had an intact uterus, was significantly associated with a higher breast cancer incidence but no significant difference in breast cancer mortality.
IMPORTANCE: Health outcomes from the Women’s Health Initiative Estrogen Plus Progestin and Estrogen-Alone Trials have been reported, but previous publications have generally not focused on all-cause ...and cause-specific mortality. OBJECTIVE: To examine total and cause-specific cumulative mortality, including during the intervention and extended postintervention follow-up, of the 2 Women’s Health Initiative hormone therapy trials. DESIGN, SETTING, AND PARTICIPANTS: Observational follow-up of US multiethnic postmenopausal women aged 50 to 79 years enrolled in 2 randomized clinical trials between 1993 and 1998 and followed up through December 31, 2014. INTERVENTIONS: Conjugated equine estrogens (CEE, 0.625 mg/d) plus medroxyprogesterone acetate (MPA, 2.5 mg/d) (n = 8506) vs placebo (n = 8102) for 5.6 years (median) or CEE alone (n = 5310) vs placebo (n = 5429) for 7.2 years (median). MAIN OUTCOMES AND MEASURES: All-cause mortality (primary outcome) and cause-specific mortality (cardiovascular disease mortality, cancer mortality, and other major causes of mortality) in the 2 trials pooled and in each trial individually, with prespecified analyses by 10-year age group based on age at time of randomization. RESULTS: Among 27 347 women who were randomized (baseline mean SD age, 63.4 7.2 years; 80.6% white), mortality follow-up was available for more than 98%. During the cumulative 18-year follow-up, 7489 deaths occurred (1088 deaths during the intervention phase and 6401 deaths during postintervention follow-up). All-cause mortality was 27.1% in the hormone therapy group vs 27.6% in the placebo group (hazard ratio HR, 0.99 95% CI, 0.94-1.03) in the overall pooled cohort; with CEE plus MPA, the HR was 1.02 (95% CI, 0.96-1.08); and with CEE alone, the HR was 0.94 (95% CI, 0.88-1.01). In the pooled cohort for cardiovascular mortality, the HR was 1.00 (95% CI, 0.92-1.08 8.9 % with hormone therapy vs 9.0% with placebo); for total cancer mortality, the HR was 1.03 (95% CI, 0.95-1.12 8.2 % with hormone therapy vs 8.0% with placebo); and for other causes, the HR was 0.95 (95% CI, 0.88-1.02 10.0% with hormone therapy vs 10.7% with placebo), and results did not differ significantly between trials. When examined by 10-year age groups comparing younger women (aged 50-59 years) to older women (aged 70-79 years) in the pooled cohort, the ratio of nominal HRs for all-cause mortality was 0.61 (95% CI, 0.43-0.87) during the intervention phase and the ratio was 0.87 (95% CI, 0.76-1.00) during cumulative 18-year follow-up, without significant heterogeneity between trials. CONCLUSIONS AND RELEVANCE: Among postmenopausal women, hormone therapy with CEE plus MPA for a median of 5.6 years or with CEE alone for a median of 7.2 years was not associated with risk of all-cause, cardiovascular, or cancer mortality during a cumulative follow-up of 18 years. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00000611
In the Women's Health Initiative (WHI) randomized trial with 10,739 postmenopausal women with prior hysterectomy, conjugated equine estrogen (CEE) alone significantly reduced breast cancer incidence ...and breast cancer mortality. In contrast, epidemiological studies in a meta-analysis from the Collaborative Group on Hormonal Factors in Breast Cancer (Collaborative Group) with 108,647 breast cancers and the Million Women's Study cohort significantly associated estrogen-alone therapy with higher breast cancer incidence and breast cancer mortality. The Collaborative Group included a meta-analysis of five smaller randomized trials and the WHI randomized trial; however, findings were restricted to the Collaborative Group appendix. Our objective is to facilitate understanding of these discordant results.
Data sources supporting our review findings include the randomized WHI CEE-alone trial and the meta-analysis of five smaller randomized trials evaluating estrogen alone. We summarize the smaller randomized trials' details of breast cancer relevance and place the findings in clinical context. We review findings of the WHI randomized trial evaluating CEE alone in the context of issues raised by Collaborative Group and the Million Women Study authors. We trace the evolution of the time-from-menopause, "window of opportunity" concept and augment the Collaborative Group meta-analysis by including the most recent WHI findings.
Consideration of the smaller randomized trials evaluating estrogen alone with breast cancer signals that the WHI findings of lower breast cancer incidence and lower breast cancer mortality with CEE-alone use are not a "stand-alone" outcome or due to the play of chance. The serial reports of consistent favorable breast cancer findings through 20 years of cumulative follow-up suggest CEE-alone use initiates changes that persist. After full consideration of risks and benefits, randomized trial evidence provides reassurance for postmenopausal women with prior hysterectomy who are close to menopause considering estrogen alone for climacteric symptom management.
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