Prediagnostic use of hormone therapy and mortality after breast cancer

Menopausal hormone therapy and incidence, mortality, and survival of breast cancer subtypes: a prospective cohort study

BACKGROUND

Menopausal hormone therapy (MHT) is associated with an increased risk of postmenopausal breast cancer, predominantly the luminal A-like subtype. The impact of MHT on deaths from breast cancer subtypes is less understood. This study aimed to explore associations between MHT use and the incidence, mortality, and survival of intrinsic-like breast cancer subtypes.

METHODS

Data from 160,881 participants with self-reported MHT use from the prospective Norwegian Women and Cancer Study were analyzed. Among them, 7,844 incident breast cancer cases, and 721 breast cancer-specific deaths occurred. Cox proportional hazard regression was performed to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for the association between MHT use and the incidence, mortality, and survival of breast cancer subtypes.

RESULTS

MHT use was associated with increased risk of overall, luminal A-like, and luminal B-like breast cancer, with respective HRs of 1.44 (95% CI 1.36-1.52), 1.41 (95% CI 1.31-1.52), and 1.23 (95% CI 1.09-1.40) among current estrogen-progestin therapy (EPT) users compared with never users. The risk increased by 4%, 4%, and 2% per year of EPT use for overall, luminal A-like, and luminal B-like breast cancers, respectively. MHT use was also associated with increased risk of overall and luminal A-like breast cancer mortality, with HRs 1.61% (95% CI 1.36-1.91) and 2.15% (95% CI 1.51-3.05) increased risk among current EPT users compared with non-users. Among patients with breast cancer, pre-diagnostic MHT use was not associated with worse survival from overall breast cancer but was inversely associated with survival from triple-negative breast cancer (TNBC; HR death 0.41; 95% CI 0.24-0.73 among current users). Results varied significantly according to tumor subtype (pheterogeneity = 0.02).

CONCLUSIONS

Our study suggests that MHT use increases the risk of incident and fatal overall and luminal A-like, and incident luminal B-like breast cancer but does not decrease overall survival among patients with breast cancer. Further research is needed to elucidate the mechanisms underlying MHT use and breast cancer lethality, and to explore whether MHT use among patients with TNBC is indeed free from harm.

The association of breast cancer patients survival and prior menopausal hormone therapy in women with type 2 diabetes

We investigated the association of prediagnostic use of menopausal hormone therapy (MHT) with breast cancer survival among women with type 2 diabetes (T2D). The study cohort was identified from a Finnish nationwide diabetes database, and consisted of women with T2D, who were diagnosed with breast cancer between 2000 and 2011 (n = 3189). The patients were classified according to their previous MHT use: systemic MHT, local MHT, and no history of any MHT. The cumulative mortality from breast cancer, cardiovascular diseases, and other causes in three MHT groups was described by the Aalen-Johansen estimator. The cause-specific mortality rates were analyzed by Cox models, and adjusted hazard ratios (HRs) were estimated for the use of MHT. The breast cancer mortality appeared to be lower among systemic MHT users (HR 0.49, 95% Cl 0.36-0.67) compared with non-users of MHT. The mortality from cardiovascular diseases and from other causes of death was found to be lower among systemic MHT users, (HR 0.49, 95% Cl 0.32-0.74), and (HR 0.51, 95% Cl 0.35-0.76), respectively. In conclusion, prediagnostic systemic MHT use is associated with reduced breast cancer, cardiovascular, and other causes of mortality in women with T2D.

Long-term survival of non-localized epithelial ovarian cancer among women using menopausal hormone therapy prior to diagnosis - the Extreme study

Prediagnostic use of menopausal hormone therapy (MHT) has been suggested to be associated with improved survival of epithelial ovarian cancer (EOC). We investigated the potential long‐term survival benefit of prediagnostic MHT use in women ≥50 years with nonlocalized EOC using the Extreme study including all women in Denmark registered with nonlocalized EOC during 2000 to 2014 (N = 3776). We obtained individual‐level information on prediagnostic use of systemic estrogen therapy (ET) and estrogen plus progestin therapy (EPT) from the National Prescription Registry and estimated absolute and relative 5‐ and 10‐year survival probabilities with 95% confidence intervals (CIs) using pseudo‐values, taking into account histology, comorbidity, income and residual disease. Among women not having used prediagnostic MHT, 5‐ and 10‐year absolute survival probabilities were 19% and 11%, respectively. Compared to MHT nonusers, prediagnostic systemic ET use for 3 to 4 years and ≥ 5 years was associated with 1.43 (95% CI: 1.01‐2.02) and 1.22 (95% CI: 0.96‐1.55) times higher 5‐year survival probabilities, respectively. Ten‐year survival probabilities were also increased but not statistically significantly. Among prediagnostic EPT users, increased 5‐year (1.14, 95% CI: 0.85‐1.53) and 10‐year (1.38, 95% CI: 0.91‐2.08) survival probabilities were observed after use for 3 to 4 years compared to MHT nonuse, whereas EPT use for ≥5 years was not associated with long‐term survival of nonlocalized EOC. Our findings may suggest a better long‐term survival of nonlocalized EOC in women having used long‐term prediagnostic ET. However, the statistical precision of our results did not allow firm conclusions and more studies are needed.

Prognostic Impact of Menopausal Hormone Therapy in Breast Cancer Differs According to Tumor Characteristics and Treatment

This study investigated how a history of menopausal hormone therapy (MHT) impacts clinical outcomes overall and in different subgroups of breast cancer patients. The study included 814 primary breast cancer patients aged ≥50 years in Sweden (2002–2012) with follow-up until 2016. Associations between patient- and tumor characteristics, recurrences, and overall survival were analyzed in relation to MHT. After a median follow-up of 7 years, 119 recurrences, and 111 deaths occurred. Ever MHT (n = 433, 53.2%) was associated with a lower BMI, frequency of alcohol abstinence, and histological grade, higher frequency of oral contraceptive use, and lobular cancer. Overall, MHT was not associated with prognosis, but there were significant effect modifications by estrogen receptor (ER) status, node status, main histological type, and aromatase inhibitor (AI) treatment on recurrence-risk (all P_interactions≤ 0.017). MHT conferred an increased recurrence-risk in patients with ER- tumors, adjusted Hazard Ratio (HR_adj) 3.99 (95% Confidence Interval (CI) 1.40–11.33), in node-negative patients HR_adj 1.88 (95% CI 1.11–3.17), and in non-AI-treated patients HR_adj 1.81 (95% CI 1.01–3.24), but decreased recurrence-risk in AI-treated patients HR_adj 0.46 (95% CI 0.25–0.84) and in patients with lobular cancer HR_adj 0.15 (95% CI 0.04–0.64). MHT was associated with lower risk of death in node-positive patients HR_adj of 0.48 (95% CI 0.27–0.86) and in AI-treated patients HR_adj of 0.41 (95% CI 0.22–0.77), but not in other patients (both P_interactions≤ 0.027). A history of MHT may have prognostic value for certain subgroups of breast cancer patients such as AI-treated or node-negative patients.

Hormone replacement therapy and breast cancer survival: a systematic review and meta-analysis of observational studies

Previous studies on the association between hormone replacement therapy (HRT) and breast cancer survival have yielded mixed results. We aimed to perform a meta-analysis to assess the association with all available studies. Relevant studies were identified by searching PubMed and EMBASE to April 2017. We calculated the summary hazard ratios (HRs) and 95% confidence intervals (CIs) using random-effects models. The dose-response relationship was assessed by random-effects meta-analysis and dose-response meta-regression models. Forty cohort studies and two case-control studies involving 1,756,833 participants were included. The results showed that prediagnosis HRT use was associated with decreased risk of dying from breast cancer (HR = 0.88, 95% CI 0.81-0.97) or any cause (HR = 0.79, 95% CI 0.69-0.90). Postdiagnosis HRT use also showed a beneficial effect on breast cancer survival. In the subgroup analyses, we found that patients who were current users at diagnosis or who received combined hormone therapy before diagnosis seemed to show more benefit from HRT use. In dose-response analysis, we observed a linear relationship between prediagnosis HRT and breast cancer-specific mortality and a 1-year increment in duration of exposure to HRT conferred an HR of 0.99 (95% CI 0.98-1.00) for death from breast cancer. In conclusion, the average effect of HRT use seems not harmful to breast cancer survival. Nevertheless, this effect of HRT use is needed for further assessment.

Estrogen-progestin use and breast cancer characteristics in lean and overweight postmenopausal women

PURPOSE

Breast cancer associated with estrogen-progestin (EP) therapy may have more favorable characteristics than cancer in never users, but results are conflicting. It is not well known either whether Body Mass Index (BMI) modifies this association. We investigated breast cancer characteristics in EP users for lean (BMI < 25 kg/m²) and overweight women (BMI ≥ 25 kg/m²).

METHODS

The Icelandic Cancer Detection Clinic cohort, with information on breast cancer risk factors for 90% of Icelandic women, was linked with the population-based Icelandic Cancer Registry. A total of 781 women with invasive breast cancer diagnosed 51 years or older were matched with 7761 controls from the cohort. Conditional logistic regression was used for estimating adjusted odds ratios (OR) and 95% confidence intervals (CI) according to tumor characteristics, stratified by BMI. Polytomous logistic regression was applied in a case-only analysis for testing whether the risk associated with EP use differed according to tumor characteristics.

RESULTS

Ever EP users had a twofold higher risk of breast cancer compared with never users (OR 2.05, 95% CI 1.71-2.45). In lean women, EP use was significantly less likely to be associated with grade 2 or 3 tumors than grade 1 tumors, contrary to overweight women for whom risk was increased irrespective of grade. EP use in overweight women was associated with a higher risk of lobular than ductal cancer (OR 2.75, 95% CI 1.29-5.87).

CONCLUSION

Among lean EP users, tumor characteristics were more favorable than among never users. This effect was not observed for overweight women.

Relationship between menopausal hormone therapy and mortality after breast cancer The MARIEplus study, a prospective case cohort

Cohort studies of breast cancer (BC) patients, but not of disease-free women at inclusion, have found menopausal hormone therapy (MHT) to be associated with decreased BC specific mortality (BCM). Here, the German population-based MARIEplus BC cohort was analyzed to further elucidate associations of prediagnostic MHT with BCM (and modification by tumor characteristics), recurrence, and secondarily with other cause and overall mortality. Enrolled 2002-2005, incident invasive BC cases (N = 3,321) were followed up for a median of 6.1 years. Cox proportional hazards models adjusted for tumor characteristics, mammography and lifestyle were applied. Compared with never users of MHT, current users at date of diagnosis had significantly lower BCM (Hazard ratio (HR) 0.72, 95% CI 0.53-0.97) and risk of recurrence (HR 0.61, 95% CI 0.46-0.82). The MHT related reduced BCM was confined to patients with low grade tumors (HR 0.44, 95% CI 0.28-0.70; phet  = 0.01) and not modified by estrogen receptor or nodal status. BCM decreased with MHT duration in current and increased in past users (phet  = 0.015). Mortality due to causes other than BC and overall mortality were also reduced in current MHT users (HR 0.51, 95% CI 0.32-0.81, HR 0.66, 95% CI 0.52-0.86, respectively). Favorable tumor characteristics and mammographic surveillance could not fully explain associations of current MHT use with BCM and recurrence risk. Thus, the study contributes to the evidence that prediagnostic MHT does not have a negative impact on prognosis after BC. The restriction of a reduced BCM to low grade tumors should be confirmed in independent studies.

Menopausal hormone therapy and breast cancer mortality: clinical implications

The Women's Health Initiative (WHI) has conducted two randomized, placebo-controlled clinical trials to evaluate the influence of menopausal hormone therapy on chronic disease risk. Estrogen plus progestin was evaluated in 16,608 postmenopausal women without prior hysterectomy during 5.6 years' intervention. In that setting, combined hormone therapy use significantly increased breast cancer incidence and interfered with breast cancer detection. The breast cancers were not limited to estrogen receptor positive, favorable prognosis cancers and were identified at more advanced stage. As a result, deaths from breast cancer were significantly increased by estrogen plus progestin use. While the absolute breast cancer risk for relatively short term (2-4 years) use of combined hormone therapy is small, on a population basis a therapy which nearly doubles deaths from breast cancer requires cautious use. Estrogen alone was evaluated in 10,739 postmenopausal women with prior hysterectomy during 7.1 years' intervention. There was an overall reduction of breast cancer incidence seen with estrogen alone use and a suggestion that the effect on risk was more pronounced in women initiating hormone therapy further from menopause. Nonetheless, women with prior hysterectomy can be assured that short duration estrogen alone use for climacteric symptom management is relatively safe. Neither estrogen plus progestin nor estrogen alone should be used for chronic disease risk reduction. The safety of duration of use on chronic disease risk longer than in the WHI clinical trials is not defined.

Pre-diagnosis oophorectomy, estrogen therapy and mortality in a cohort of women diagnosed with breast cancer

Introduction

Pre-diagnosis oophorectomy and estrogen therapy could impact mortality due to breast cancer and cardiovascular disease (CVD) among breast cancer survivors. Elective bilateral oophorectomy at the time of hysterectomy for benign conditions is not uncommon among US women.

Methods

We examined the association between pre-diagnosis total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAHBSO) and both overall and cause-specific mortality in the Collaborative Breast Cancer Studies cohort. Medical history and prior estrogen use were collected during standardized telephone interviews. Vital status, including date and cause of death, was obtained by linkage with the National Death Index. Multivariate hazard ratios (HR) and 95% confidence intervals (CI) for cause-specific mortality were calculated using Cox proportional hazards regression.

Results

Seventeen percent (N = 1,778) of breast cancer survivors (mean age at diagnosis = 63.5) reported pre-diagnosis TAHBSO. During follow-up (mean = 9.5 years), 2,856 deaths occurred, including 1,060 breast cancer deaths and 459 CVD deaths. Breast cancer deaths occurred a median of 5.1 years after diagnosis; CVD deaths occurred further from diagnosis (median = 9.7 years). Women who reported pre-diagnosis TAHBSO had a 16% decrease in all-cause mortality (HR = 0.84; 95% CI: 0.76, 0.92) compared to those with an intact uterus and ovaries. This overall decrease reflected a 27% lower breast cancer mortality among women who never used postmenopausal hormones (HR = 0.73; CI: 0.55, 0.96) and 43% lower CVD risk among women who reported using estrogen (HR = 0.57; CI: 0.39, 0.83) after TAHBSO.

Conclusions

Information on prior TAHBSO and estrogen use can inform risk of death from both breast cancer and cardiovascular disease among breast cancer survivors.

Fatal breast cancer risk in relation to use of unopposed estrogen and combined hormone therapy

Use of combined hormone therapy (CHT) is associated with increased breast cancer incidence, but it is unclear whether this translates into increased breast cancer mortality. To address this question, we conducted a population-based nested case-control study in Saskatchewan, Canada, where a population-based prescription drug database has existed since 1975. We evaluated fatal breast cancer risk in relation to recency and duration of use of CHT and unopposed estrogen hormone therapy (EHT). A total of 1,288 cases and 12,535 controls were included in the analyses. Exclusive use of EHT was not associated with fatal breast cancer risk, either overall or within categories of recency or duration [odds ratio (OR) for current vs. never use = 1.1; 95 % confidence interval (CI) 0.8-1.3]. Use of CHT (includes women who had also used EHT) was also not associated with fatal breast cancer risk (OR for current vs. never use = 0.9; 95 % CI 0.7-1.3), except for a suggestion of an increased risk with current long-term use. Consistent with prior studies, we observed no increased risk of fatal breast cancer associated with use of EHT. To date only a few studies have evaluated fatal breast cancer risk in relation to use of CHT, and collectively the results are inconsistent.

[Still a place for hormone replacement therapy?]

Hormone replacement therapy (HRT) remains the most efficient treatment to alleviate climacteric symptoms. The drastic decline in their prescription following the WHI is not fully justified. Benefits might be more important than harm in women 50-60 years. French way of treatment does not increase the risk in thrombosis nor stroke and breast cancer risk is less important than with other regimen. One of the major benefits of HRT is the decrease in type 2 diabetes with all the treatments including the French ones. The results of the American randomized trials cannot be fully extrapolated to young postmenopausal women with less cardiovascular risk factors.

Use of β-blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and risk of breast cancer recurrence: a Danish nationwide prospective cohort study

PURPOSE

To estimate associations between use of β-blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs) and breast cancer recurrence in a large Danish cohort.

PATIENTS AND METHODS

We enrolled 18,733 women diagnosed with nonmetastatic breast cancer between 1996 and 2003. Patient, treatment, and 10-year recurrence data were ascertained from the Danish Breast Cancer Cooperative Group registry. Prescription and medical histories were ascertained by linkage to the National Prescription Registry and Registry of Patients, respectively. β-Blocker exposure was defined in aggregate and according to solubility, receptor selectivity, and individual drugs. ACE inhibitor and ARB exposures were defined in aggregate. Recurrence associations were estimated with multivariable Cox regression models in which time-varying drug exposures were lagged by 1 year.

RESULTS

Compared with never users, users of any β-blocker had a lower recurrence hazard in unadjusted models (unadjusted hazard ratio [HR] = 0.91; 95% CI, 0.81 to 1.0) and a slightly higher recurrence hazard in adjusted models (adjusted HR = 1.3; 95% CI, 1.1 to 1.5). Associations were similar for exposures defined by receptor selectivity and solubility. Although most individual β-blockers showed no association with recurrence, metoprolol and sotalol were associated with increased recurrence rates (adjusted metoprolol HR = 1.5, 95% CI, 1.2 to 1.8; adjusted sotalol HR = 2.0, 95% CI, 0.99 to 4.0). ACE inhibitors were associated with a slightly increased recurrence hazard, whereas ARBs were not associated with recurrence (adjusted ACE inhibitor HR = 1.2, 95% CI, 0.97 to 1.4; adjusted ARBs HR = 1.1, 95% CI, 0.85 to 1.3).

CONCLUSION

Our data do not support the hypothesis that β-blockers attenuate breast cancer recurrence risk.

Alcohol consumption before and after breast cancer diagnosis: associations with survival from breast cancer, cardiovascular disease, and other causes

PURPOSE

Alcohol intake is associated with increased risk of breast cancer. In contrast, the relation between alcohol consumption and breast cancer survival is less clear.

PATIENTS AND METHODS

We assessed pre- and postdiagnostic alcohol intake in a cohort of 22,890 women with incident invasive breast cancer who were residents of Wisconsin, Massachusetts, or New Hampshire and diagnosed from 198 to 200 at ages 20 to 79 years. All women reported on prediagnostic intake; a subsample of 4,881 reported on postdiagnostic intake.

RESULTS

During a median follow-up of 11.3 years from diagnosis, 7,780 deaths occurred, including 3,484 resulting from breast cancer. Hazard ratios (HR) and 95% CIs were estimated. Based on a quadratic analysis, moderate alcohol consumption before diagnosis was modestly associated with disease-specific survival (compared with nondrinkers, HR = 0.93 [95% CI, 0.85 to 1.02], 0.85 [95% CI, 0.75 to 0.95], 0.88 [95% CI, 0.75 to 1.02], and 0.89 [95% CI, 0.77 to 1.04] for two or more, three to six, seven to nine, and ≥ 10 drinks/wk, respectively). Alcohol consumption after diagnosis was not associated with disease-specific survival (compared with nondrinkers, HR = 0.88 [95% CI, 0.61 to 1.27], 0.80 [95% CI, 0.49 to 1.32], 1.01 [95% CI, 0.55 to 1.87], and 0.83 [95% CI, 0.45 to 1.54] for two or more, three to six, seven to nine, and ≥ 10 drinks/wk, respectively). Results did not vary by beverage type. Women consuming moderate levels of alcohol, either before or after diagnosis, experienced better cardiovascular and overall survival than nondrinkers.

CONCLUSION

Overall alcohol consumption before diagnosis was not associated with disease-specific survival, but we found a suggestion favoring moderate consumption. There was no evidence for an association with postdiagnosis alcohol intake and breast cancer survival. This study, however, does provide support for a benefit of limited alcohol intake for cardiovascular and overall survival in women with breast cancer.

Estrogen plus progestin and breast cancer incidence and mortality in the Women's Health Initiative Observational Study

BACKGROUND

In the Women's Health Initiative (WHI) randomized trial, estrogen plus progestin increased both breast cancer incidence and mortality. In contrast, most observational studies associate estrogen plus progestin with favorable prognosis breast cancers. To address differences, a cohort of WHI observational study participants with characteristics similar to the WHI clinical trial was studied.

METHODS

We identified 41 449 postmenopausal women with no prior hysterectomy and mammogram negative within 2 years who were either not hormone users (n = 25 328) or estrogen and progestin users (n = 16 121). Multivariable-adjusted Cox proportional hazard regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CI). All statistical tests were two-sided.

RESULTS

After a mean of 11.3 (SD = 3.1) years, with 2236 breast cancers, incidence was higher in estrogen plus progestin users than in nonusers (0.60% vs 0.42%, annualized rate, respectively; HR = 1.55, 95% CI = 1.41 to 1.70, P < .001). Women initiating hormone therapy closer to menopause had higher breast cancer risk with linear diminishing influence as time from menopause increased (P < .001). Survival after breast cancer, measured from diagnosis, was similar in combined hormone therapy users and nonusers (HR = 1.03, 95% CI = 0.79 to 1.35). On a population basis, there were somewhat more deaths from breast cancer, measured from cohort entry (HR = 1.32, 95% CI = 0.90 to 1.93, P = .15), and more all-cause deaths after breast cancer (HR = 1.65, 95% CI = 1.29 to 2.12, P < .001) in estrogen plus progestin users than in nonusers.

CONCLUSIONS

Consistent with WHI randomized trial findings, estrogen plus progestin use is associated with increased breast cancer incidence. Because prognosis after diagnosis on combined hormone therapy is similar to that of nonusers, increased breast cancer mortality can be expected.

Breast cancer in women using digoxin: tumor characteristics and relapse risk

Introduction

Digoxin use is associated with increased incidence of breast and uterus cancers. We postulated that digoxin use might affect tumor characteristics and increase relapse risk in women with breast cancer.

Methods

Incident breast cancer cases in Danish women (n = 49,312; 1995 to 2008) were identified. Analyses were conducted in women 20 to 74 years old. Relapse hazard ratios (HR) were compared in women using and not using digoxin, adjusting for age, calendar period, protocol, tumor size, nodal involvement, histology grade, estrogen-receptor (ER) status, and anti-estrogen therapy in Cox regression models.

Results

At diagnosis, tumors in digoxin users were more likely ER+ (85.4% vs. 78.6%: P = 0.002) and have grade 1 ductal histology (37.2% vs. 25.7%; P = 0.004), compared to non-users. 45 relapses occurred in women already using digoxin at breast cancer diagnosis (1,487 person-years); 24 relapses occurred in women later starting digoxin (384 person-years). Overall relapse risk HR in digoxin users was 1.13 (95% confidence interval: 0.88, 1.46) compared to non-users. Relapse risk in digoxin users was significantly increased in the first year (2.19; 1.26, 3.78) but not thereafter (0.99; 0.74, 1.32) (P = 0.02 for difference in HRs). First-year relapse hazard was high in digoxin-using women with ER+ tumors (2.51; 1.39, 4.55) but not ER- tumors (0.72; 0.10, 5.27). Recurrence hazard was not significantly changed among digoxin-using women also using tamoxifen.

Conclusions

Breast cancers arising in digoxin-using women had better prognostic features. After adjustment for markers, overall breast cancer relapse risk in digoxin users was not increased significantly, although recurrence hazards for ER+ tumors were higher in the first year following diagnosis.

[Menopause and oncologic risks]

Since the Women's health Initiative (WHI) study published in 2002, hormonal replacement therapy (HRT) prescription is discussed, especially concerning the risk of cancer, and breast cancer in particular. This calling into question led France to publish in 2004 ANAES and AFFAPS recommendations. From recent literature data published by the EMAS, the North American Society and CNGOF, this study aim to discuss cancer risk under HRT. The relative risk (RR) of breast cancer varies from 1.26 in the WHI study to 1.66 in the Million Women Study, with different results according to the interval between menopause and starting hormone therapy and the modalities of HRT (different data for estrogen-only hormone therapy, or within the type of progestogen used). However, impact of breast cancer decreases since 2004, in which role of HRT is difficult to specify. Part of HRT in ovarian cancer is controversial, data being discordant in recent studies and mainly involving estrogen-only hormone therapy. Regarding protective property in endometrial cancer, the dose and duration of progestogen therapy seem to be the main factors. At last, there is no evidence as regards the role of HRT in drop of colon cancer incidence or increased mortality by pulmonary cancer. These updates data must be part of patient information before introducing HRT, in order to get the best evaluation of individual risk and benefit of this treatment.

Changing concepts: Menopausal hormone therapy and breast cancer

Hormone therapy is still used by millions of women for menopausal symptoms. Concerns regarding hormone therapy and breast cancer were initially based on case reports and retrospective case-control studies. However, recent results from large prospective cohort studies and the Women's Health Initiative (WHI) randomized placebo-controlled hormone therapy trials have substantially changed concepts regarding how estrogen alone and estrogen plus progestin influence breast cancer. The preponderance of observational studies suggested that estrogen alone and estrogen plus progestin both increased the risk of breast cancer, with cancers commonly diagnosed at an early stage. However, substantially different results emerged from the WHI randomized hormone therapy trials. In the WHI trial evaluating estrogen plus progestin in postmenopausal women with an intact uterus, combined hormone therapy statistically significantly increased the risk of breast cancer and hindered breast cancer detection, leading to delayed diagnosis and a statistically significant increase in breast cancer mortality. By contrast, estrogen alone use by postmenopausal women with prior hysterectomy in the WHI trial did not substantially interfere with breast cancer detection and statistically significantly decreased the risk of breast cancer. Differential mammography usage patterns may explain differences between observational study and randomized trial results. In clinical practice, hormone therapy users have mammograms more frequently than nonusers, leading to more and earlier stage cancer detection. By contrast, in the WHI randomized trials, mammogram frequency was protocol mandated and balanced between comparison groups. Currently, the different effects of estrogen plus progestin vs estrogen alone on breast cancer are not completely understood.

Conjugated equine oestrogen and breast cancer incidence and mortality in postmenopausal women with hysterectomy: extended follow-up of the Women's Health Initiative randomised placebo-controlled trial

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.

Statin prescriptions and breast cancer recurrence risk: a Danish nationwide prospective cohort study

BACKGROUND

Accumulating evidence suggests that statins affect diseases other than cardiovascular disease, including cancer, and that these effects may depend on the lipid solubility of specific statins. Though many studies have reported an association between statin use and breast cancer incidence, the relationship between statin use and breast cancer recurrence has not been well studied.

METHODS

We conducted a nationwide, population-based prospective cohort study of all female residents in Denmark diagnosed with stage I-III invasive breast carcinoma who were reported to the Danish Breast Cancer Cooperative Group registry between 1996 and 2003 (n = 18,769). Women were followed for a median of 6.8 years after diagnosis. Prescriptions for lipophilic and hydrophilic statins were ascertained from the national electronic pharmacy database. Associations between statin prescriptions and breast cancer recurrence were estimated with generalized linear models and Cox proportional hazards regression with adjustment for age and menopausal status at diagnosis; histological grade; estrogen receptor status; receipt of adjuvant therapy; type of primary surgery received; pre-diagnosis hormone replacement therapy; and co-prescriptions of aspirin, angiotensin-converting enzyme inhibitors, nonsteroidal anti-inflammatory drugs, or anticoagulants. All statistical tests were two-sided.

RESULTS

Most prescriptions for lipophilic statins in the study population were for simvastatin. Exclusive simvastatin users experienced approximately 10 fewer breast cancer recurrences per 100 women after 10 years of follow-up (adjusted 10-year risk difference = -0.10, 95% confidence interval = -0.11 to -0.08), compared with women who were not prescribed a statin. Exclusive hydrophilic statin users had approximately the same risk of breast cancer recurrence as women not prescribed a statin over follow-up (adjusted 10-year risk difference = 0.05, 95% confidence interval = -0.01 to 0.11).

CONCLUSIONS

Simvastatin, a highly lipophilic statin, was associated with a reduced risk of breast cancer recurrence among Danish women diagnosed with stage I-III breast carcinoma, whereas no association between hydrophilic statin use and breast cancer recurrence was observed.

Breast cancer after hormone replacement therapy--does prognosis differ in perimenopausal and postmenopausal women?

Hormone replacement therapy (HRT) has been associated with higher incidence of breast cancer in postmenopausal women, but it is unclear if breast cancers developing after HRT use have different prognosis. 1053 women with hormone receptor positive non-metastasized breast cancer were analyzed in a retrospective trial, stratifying by HRT use before diagnosis. Postmenopausal HRT users had significantly more early tumor stages (p<0.001). HRT in postmenopausal patients was associated with longer time to progression (TTP) (HR 0.81, 95%CI 0.55-1.19, p=0.28) and overall survival (OS) (HR 0.68, 95%CI 0.45-1.02, p=0.059). Perimenopausal HRT users showed shorter TTP and OS (HR 1.99, 95%CI 0.57-6.91, p=0.28 and HR 4.59, 95%CI 0.91-23.25, p=0.06 respectively). Higher BMI was significantly associated with poorer prognosis in perimenopausal women only (TTP: HR=1.16; OS: HR=1.31). In this retrospective analysis postmenopausal HRT users seemed to have a better breast cancer prognosis. For perimenopausal HRT users however, a trend towards worse prognosis was found.

Socioeconomic status and survival after an invasive breast cancer diagnosis

BACKGROUND

Women who live in geographic areas with high poverty rates and low levels of education experience poorer survival after a breast cancer diagnosis than women who live in communities with indicators of high socioeconomic status (SES). However, very few studies have examined individual-level SES in relation to breast cancer survival or have assessed the contextual role of community-level SES independent of individual-level SES.

METHODS

The authors of this report examined both individual-level and community-level SES in relation to breast cancer survival in a population-based cohort of women ages 20 to 69 years who were diagnosed with breast cancer in Wisconsin between 1995 and 2003 (N = 5820).

RESULTS

Compared with college graduates, women who had no education beyond high school were 1.39 times more likely (95% confidence interval [CI], 1.10-1.76) to die from breast cancer. Women who had household incomes <2.5 times the poverty level were 1.46 times more likely (95% CI, 1.10-1.92) to die from breast cancer than women who had household incomes ≥5 times the poverty level. Adjusting the analysis for use of screening mammography, disease stage at diagnosis, and lifestyle factors eliminated the disparity by income, but the disparity by education persisted (hazard ratio [HR], 1.27; 95% CI, 0.99-1.61). In multilevel analyses, low community-level education was associated with increased breast cancer mortality even after adjusting for individual-level SES (HR, 1.57; 95% CI, 1.09-2.27 for ≥20% vs <10% of adults without a high school degree).

CONCLUSIONS

The current results indicated that screening and early detection explain some of the disparity according to SES, but further research will be needed to understand the additional ways in which individual-level and community-level education are associated with survival.

Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women

CONTEXT

In the Women's Health Initiative randomized, placebo-controlled trial of estrogen plus progestin, after a mean intervention time of 5.6 (SD, 1.3) years (range, 3.7-8.6 years) and a mean follow-up of 7.9 (SD, 1.4) years, breast cancer incidence was increased among women who received combined hormone therapy. Breast cancer mortality among participants in the trial has not been previously reported.

OBJECTIVE

To determine the effects of therapy with estrogen plus progestin on cumulative breast cancer incidence and mortality after a total mean follow-up of 11.0 (SD, 2.7) years, through August 14, 2009.

DESIGN, SETTING, AND PARTICIPANTS

A total of 16,608 postmenopausal women aged 50 to 79 years with no prior hysterectomy from 40 US clinical centers were randomly assigned to receive combined conjugated equine estrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5 mg/d, or placebo pill. After the original trial completion date (March 31, 2005), reconsent was required for continued follow-up for breast cancer incidence and was obtained from 12,788 (83%) of the surviving participants.

MAIN OUTCOME MEASURES

Invasive breast cancer incidence and breast cancer mortality.

RESULTS

In intention-to-treat analyses including all randomized participants and censoring those not consenting to additional follow-up on March 31, 2005, estrogen plus progestin was associated with more invasive breast cancers compared with placebo (385 cases [0.42% per year] vs 293 cases [0.34% per year]; hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.07-1.46; P = .004). Breast cancers in the estrogen-plus-progestin group were similar in histology and grade to breast cancers in the placebo group but were more likely to be node-positive (81 [23.7%] vs 43 [16.2%], respectively; HR, 1.78; 95% CI, 1.23-2.58; P = .03). There were more deaths directly attributed to breast cancer (25 deaths [0.03% per year] vs 12 deaths [0.01% per year]; HR, 1.96; 95% CI, 1.00-4.04; P = .049) as well as more deaths from all causes occurring after a breast cancer diagnosis (51 deaths [0.05% per year] vs 31 deaths [0.03% per year]; HR, 1.57; 95% CI, 1.01-2.48; P = .045) among women who received estrogen plus progestin compared with women in the placebo group.

CONCLUSIONS

Estrogen plus progestin was associated with greater breast cancer incidence, and the cancers are more commonly node-positive. Breast cancer mortality also appears to be increased with combined use of estrogen plus progestin.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000611.

Age-related variation in the relationship between menopausal hormone therapy and the risk of dying from breast cancer

Multiple past studies have reported a reduced risk of breast cancer-related mortality (BCM) in relation to pre-diagnostic use of hormone therapy (HT); however, the extent to which this reduction is due to heightened screening or tumor biology is unknown. Using a population-based cohort of 1,911 post-menopausal women diagnosed with invasive breast cancer at ages 45-79 from 1993 to 1999, we investigated the extent to which the reduced risk in BCM observed in relation to HT might be explained by screening patterns or tumor features. Estrogen-progestin therapy (EPT) use was associated with a decreased risk of BCM (after adjustment for age, study, mammography, stage, and treatment), but only among older women (ever use: ≥ 65 years: HR = 0.45 [95% CI 0.26-0.80]; <65 years: HR = 1.03 [95% CI 0.60-1.79]). Estrogen-alone therapy (ET) use was not associated with risk of BCM (ever use: ≥ 65 years: HR = 0.76 [95% CI 0.51-1.12]; <65 years: HR = 1.20 [95% CI 0.71-2.02]). HT users had a much greater frequency of mammography (P value <0.001). EPT use was associated with tumor characteristics related to improved prognosis in older women after adjustment for screening, including an inverse association with poorly differentiated tumors (OR = 0.57 [95% CI 0.38-0.85]) and an association with lobular tumors (OR = 1.68 [95% CI 1.07-2.65]). Beyond the influence of EPT use on screening uptake, these data indicate that the improved survival associated with pre-diagnostic EPT use may be due in part to the development of more favorable tumor characteristics.

Menopausal hormone therapy and risk of clinical breast cancer subtypes

BACKGROUND

Breast cancer is a heterogeneous disease with subtypes that may vary in their etiologies. Menopausal hormone therapy has been associated more strongly with lobular and tubular than ductal histologic types and with tumors that are smaller, hormone receptor-positive, and of lower grade. At the same time, correlations have been observed between histology and clinical characteristics. To identify those tumor subtypes most strongly associated with hormone therapy use, it is necessary to disentangle these interrelationships.

METHODS

Based on 3,464 postmenopausal breast cancer cases and 6,657 controls from the population-based Mammary carcinoma Risk factor Investigation study, we used polytomous logistic regression to evaluate associations between hormone therapy use and risk of invasive breast cancer subtypes. We assessed variations in risk for selected tumor characteristics among histologic and hormone receptor subtypes, both overall and for specific hormone therapy regimens.

RESULTS

Lobular and mixed types showed less variation by prognostic factors than did ductal tumors. Current hormone therapy use had the strongest associations with prognostic variables in estrogen receptor (ER)-positive and/or progesterone receptor (PR)-positive ductal tumors and in lobular tumors regardless of ER/PR status, with little effect on ER/PR-negative ductal tumors. The observed associations varied minimally by hormone therapy type or regimen.

CONCLUSION

Current hormone therapy use was associated with more favorable breast cancer characteristics for ductal tumors but had less effect on prognostic characteristics in women with lobular tumors. Both histologic type and estrogen receptor/progesterone receptor status seem to be important in explaining the role of hormone therapy in the etiology of breast cancer subtypes.