Estrogen replacement therapy after breast cancer: a 12-year follow-up

Hormone Replacement Therapy After Breast Cancer: It Is Time

ABSTRACT

This article reviews the decades of evidence supporting the reproducible benefits of HRT for menopausal symptom control, improved cardiac health, prevention of hip fracture, reduction in the risk and pace of cognitive decline, and enhanced longevity. It quantifies the increased risk of thromboembolism associated with oral, though not transdermal, HRT. It evaluates the repeated claims that HRT is associated with an increased risk of breast cancer development, and, when administered to breast cancer survivors, an increased risk of breast cancer recurrence. Twenty-five studies of HRT after a breast cancer diagnosis, published between 1980 and 2013, are discussed, as are the 20 reviews of those studies published between 1994 and 2021. Only 1 of the 25 studies, the HABITS trial, demonstrated an increased risk of recurrence, which was limited to local or contralateral, and not distant, recurrence. None of the studies, including HABITS, reported increased breast cancer mortality associated with HRT. Even in the HABITS trial, the absolute increase in the number of women who had a recurrence (localized only) associated with HRT administration was 22. It is on the basis of these 22 patients that HRT, with its demonstrated benefits for so many aspects of women's health, is being denied to millions of breast cancer survivors around the world.

Hormone Therapy in Menopause: Concepts, Controversies, and Approach to Treatment

Hormone therapy (HT) is an effective treatment for menopausal symptoms, including vasomotor symptoms and genitourinary syndrome of menopause. Randomized trials also demonstrate positive effects on bone health, and age-stratified analyses indicate more favorable effects on coronary heart disease and all-cause mortality in younger women (close proximity to menopause) than in women more than a decade past menopause. In the absence of contraindications or other major comorbidities, recently menopausal women with moderate or severe symptoms are appropriate candidates for HT. The Women's Health Initiative (WHI) hormone therapy trials-estrogen and progestin trial and the estrogen-alone trial-clarified the benefits and risks of HT, including how the results differed by age. A key lesson from the WHI trials, which was unfortunately lost in the posttrial cacophony, was that the risk:benefit ratio and safety profile of HT differed markedly by clinical characteristics of the participants, especially age, time since menopause, and comorbidity status. In the present review of the WHI and other recent HT trials, we aim to provide readers with an improved understanding of the importance of the timing of HT initiation, type and route of administration, and of patient-specific considerations that should be weighed when prescribing HT.

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.

Hormone Replacement Therapy: An Increased Risk of Recurrence and Mortality for Breast Cancer Patients?

Historically, randomized controlled trials (RCTs) have shown an increased risk of recurrence and mortality among women who have used primarily oral HRT after breast cancer. However, many of these studies have had design flaws that may impact the findings. Numerous investigators have concluded that additional RCTs should be performed, but because of ethical issues and logistic challenges, large-scale RCTs are unlikely. Thus, the authors conducted an integrative review investigating recurrence and mortality data among breast cancer survivors who have used hormone replacement therapy (HRT). They recommend a stepwise algorithm for treating vaginal symptoms in breast cancer survivors: (1) start with nonhormonal treatments; (2) progress to a detailed discussion among patients and health-care professionals about the current known risks and benefits of vaginal estrogen; and (3) conclude with mutual decision-making between health-care providers and patients regarding the use of vaginal estrogen treatment.

Breast cancer in premenopausal women: recurrence and survival rates and relationship to hormone replacement therapy

OBJECTIVES

To determine any association between hormonal replacement therapy (HRT) usage and breast cancer recurrence and survival rates in women who were premenopausal at the time of diagnosis of breast cancer.

METHODS

The study group comprised 524 women who were diagnosed with breast cancer when they were premenopausal. Of these, 277 women reached menopause before recurrence of the disease, being lost to follow-up, or reaching the end of the study. In this group, 119 women took HRT to control menopausal symptoms. The majority took combined continuous estrogen-progestin treatment. Times from diagnosis to cancer recurrence or new breast cancer, to death from all causes, and to death from primary tumor were compared between HRT users and non-users.

RESULTS

Women who used HRT after their menopause had an adjusted relative risk of recurrence or new breast cancer of 0.75 (95% confidence interval (CI), 0.29-1.95) compared to that of non-users. The relative risk of death from all causes was 0.36 (95% CI, 0.11-1.16) and that of death from primary tumor was 0.24 (95% CI, 0.05-1.14).

CONCLUSION

HRT use in women who were premenopausal at the diagnosis of primary invasive breast cancer is not associated with worse outcomes in terms of breast cancer recurrence or mortality.

Postmastectomy locoregional recurrence and recurrence-free survival in breast cancer patients

Background

One essential outcome after breast cancer treatment is recurrence of the disease. Treatment decision is based on assessment of prognostic factors of breast cancer recurrence. This study was to investigate the prognostic factors for postmastectomy locoregional recurrence (LRR) and survival in those patients.

Methods

114 patients undergoing mastectomy and adjuvant radiotherapy in Cancer Institute of Tehran University of Medical Sciences were retrospectively reviewed between 1996 and 2008. All cases were followed up after initial treatment of patients with breast cancer via regular visit (annually) for discovering the LRR. Cumulative recurrence free survival (RFS) was determined using the Kaplan-Meier method, with univariate comparisons between groups through the log-rank test. The Cox proportional hazards model was used for multivariate analysis.

Result

The median follow up time was 84 months (range 2-140). Twenty-three (20.2%) patients developed LRR. Cumulative RFS rate at 2.5 years and 5 years were 86% (95%CI, 81-91) and 82.5% (95%CI, 77-87) respectively. Mean RFS was 116.50 ± 4.43 months (range, 107.82 - 125.12 months, 95%CI). At univariate and multivariate analysis, factors had not any influence on the LRR.

Conclusion

Despite use of adjuvant therapies during the study, we found a LRR rate after mastectomy of 20.2%. Therefore, for patients with LRR without evidence of distant disease, aggressive multimodality therapy is warranted.

Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary

There has been considerable investigation of the potential for soyfoods to reduce risk of cancer, and in particular cancer of the breast. Most interest in this relationship is because soyfoods are essentially a unique dietary source of isoflavones, compounds which bind to estrogen receptors and exhibit weak estrogen-like effects under certain experimental conditions. In recent years the relationship between soyfoods and breast cancer has become controversial because of concerns – based mostly on in vitro and rodent data – that isoflavones may stimulate the growth of existing estrogen-sensitive breast tumors. This controversy carries considerable public health significance because of the increasing popularity of soyfoods and the commercial availability of isoflavone supplements. In this analysis and commentary we attempt to outline current concerns regarding the estrogen-like effects of isoflavones in the breast focusing primarily on the clinical trial data and place these concerns in the context of recent evidence regarding estrogen therapy use in postmenopausal women. Overall, there is little clinical evidence to suggest that isoflavones will increase breast cancer risk in healthy women or worsen the prognosis of breast cancer patients. Although relatively limited research has been conducted, and the clinical trials often involved small numbers of subjects, there is no evidence that isoflavone intake increases breast tissue density in pre- or postmenopausal women or increases breast cell proliferation in postmenopausal women with or without a history of breast cancer. The epidemiologic data are generally consistent with the clinical data, showing no indication of increased risk. Furthermore, these clinical and epidemiologic data are consistent with what appears to be a low overall breast cancer risk associated with pharmacologic unopposed estrogen exposure in postmenopausal women. While more research is required to definitively allay concerns, the existing data should provide some degree of assurance that isoflavone exposure at levels consistent with historical Asian soyfood intake does not result in adverse stimulatory effects on breast tissue.

The effect of lifestyle factors on gynaecological cancer

Several lifestyle factors affect a woman's risk of gynaecological cancer and-potentially-can be modified to reduce risk. This chapter summarises the evidence for the effect of lifestyle factors on the incidence of gynaecological malignancy. The incidence of obesity is increasing in the developed world such that it now contributes as much as smoking to overall cancer deaths. Women with a body mass index (BMI)>40 have a 60% higher risk of dying from all cancers than women of normal weight. They are also at increased risk from gynaecological cancer. Dietary factors significantly influence the risk of gynaecological cancer: fruit, vegetables and antioxidants reduce risk whereas high animal fat and energy intakes increase risk. Alcohol intake adversely affects breast cancer risk, possibly accounting for 4% of all breast cancers. Physical activity protects against ovarian, endometrial and postmenopausal breast cancer, independently of BMI. The oral contraceptive pill has a substantial and long-lasting effect on the prevention of ovarian and endometrial cancer and is one of the best examples of large-scale chemoprevention in the developed world. Childbearing is protective against ovarian, endometrial and breast cancer but increases the risk of cervical cancer. Smoking acts as a cofactor in cervical carcinogenesis and increases the risk of ovarian cancer, particularly mucinous tumours.

Menopausal hormone therapy (HT) in patients with breast cancer

OBJECTIVES

To assess the effect of menopausal hormone therapy (HT) on reoccurrence, cancer-related mortality, and overall mortality after a diagnosis of breast cancer.

METHODS

We performed a quantitative review of all studies reporting experience with menopausal HT for symptomatic use after a diagnosis of breast cancer. Rates of reoccurrence, cancer-related mortality, and overall mortality were calculated in this entire group. A subgroup analysis was performed in studies using a control population to assess the odds ratio of cancer reoccurrence and mortality in hormone users versus non-users.

RESULTS

Fifteen studies encompassing 1416 breast cancer survivors using HT were identified. Seven studies included a control group comprised of 1998 patients. Among the 1416 HT users, reoccurrence was noted in 10.0% (95% CI: 8.4-11.6%). Cancer-related mortality occurred at a rate of 2.6% (95% CI: 1.8-3.7%), while overall mortality was 4.5% (95% CI: 3.4-5.8%). Compared to non-users, patients using HT had a decreased chance of reoccurrence and cancer-related mortality with combined odds ratio of 0.5 (95% CI: 0.2-0.7) and 0.3 (95% CI: 0.0-0.6), respectively.

CONCLUSIONS

In our review, menopausal HT use in breast cancer survivors was not associated with increased cancer reoccurrence, cancer-related mortality or total mortality. Despite conflicting opinions on this issue, it is important for primary care physicians to feel comfortable medically managing the increasing number of breast cancer survivors. In the subset of women with severe menopausal symptoms, HT options should be reviewed if non-hormonal methods are ineffective. Future trials should focus on better ways to identify breast cancer survivors who may safely benefit from HT versus those who have a substantial risk of reoccurrence with HT use.

The thoughts of physicians regarding the need to start hormone replacement therapy in breast cancer survivors

OBJECTIVES

To investigate how physicians felt about HRT use in breast cancer survivors a half year after the WHI trial.

METHODS

In December 2002, a questionnaire was conducted in Flanders (Belgium). The survey contained a presentation of a 35-year-old breast cancer survivor who presented with climacteric symptoms after treatment with tamoxifen.

RESULTS

With a response rate of 33.65%, a majority of the physicians did not prescribe classical oral HRT (5.40%) in this patient. Physicians prefer to prescribe tibolone (30.68%) or other alternative treatment (50.00%). The main reason was the fear for increased recurrence of breast cancer. Furthermore the WHI oestrogen plus progestin trial and its attention in the media, a half year prior to the survey, influenced one-third of the physician's prescribing attitude.

CONCLUSIONS

Two-thirds of the physicians did not change prescribing attitude after the WHI oestrogen plus progestin trial. HRT is a well proven effective treatment in breast cancer survivors with severe climacteric complaints, but a majority of physicians is not convinced of its safety in breast cancer survivors. Therefore, a majority of physicians do not find the need to prescribe HRT in breast cancer survivors.

The characteristics of malignant breast tumors in hormone replacement therapy users versus nonusers

BACKGROUND

The purpose of this study was to investigate the characteristics of breast cancer in hormone replacement therapy (HRT) users vs. nonusers.

METHODS

We investigated the characteristics of all patients between the ages of 50 and 75 years with breast tumors. Then, an age-adjusted group of 55 nonusers was chosen to match and compare with HRT users.

RESULTS

Of the 243 patients available for evaluation, 55 (22.6%) used HRT. Disease stages in HRT users vs. nonusers were as follows: ductal carcinoma in situ (DCIS), 20% and 17.1%; stage I, 45.5% and 41.7%; stage II, 30.9% and 26.2%; stage III, 3.6% and 13.4%; and stage IV, 0% and 1.6% (P =.27). In the age-adjusted cohort, stages in nonusers were as follows: DCIS, 7.3%; stage I, 47.3%; stage II, 25.5%; stage III, 20%; and stage IV, 0% (P =.03). Tumor grades in HRT users vs. nonusers were as follows: grade I, 30.4% and 15.7%; grade II, 52.2% and 52.2%; and grade III, 17.4% and 32.1% (P =.035). Grades in cohort nonusers were as follows: I, 13.2%; II, 52.8%; and III, 34% (P =.05). In the invasive tumors, the positive estrogen receptor (ER) rates were 81.6% and 85.7% (P =.89); positive progesterone receptor (PR) rates were 53.1% and 54% (P =.95); and Her 2-neu positive rates were 18.4% and 17.6% (P =.95), respectively. No significant difference was found in intratumor DCIS, vascular invasion, and Ki-67 (P =.14,.9, and.79, respectively). The rate of lobular and favorable histological types was higher in the HRT user group: 26.6% vs. 15%.

CONCLUSIONS

Breast tumors in HRT users vs. nonusers were of a significantly lower stage and grade and accounted for a higher number of favorable histological types, but all other parameters were similar in the two groups.

Estrogen replacement therapy in breast cancer survivors: a matched-controlled series

OBJECTIVE

We prospectively administered estrogen replacement therapy (ERT) to control estrogen deficiency symptoms in breast cancer survivors as part of our clinical practice. We report the consequences of ERT compared with a historical matched-control group.

DESIGN

Two hundred seventy-seven disease-free survivors received ERT. Controls were matched for exact stage, a recurrence-free period similar to the period to ERT initiation in the ERT group, approximate age, and duration of follow-up. The mean time from breast cancer diagnosis to initiation of ERT was 3.61 (+/- 0.25) years, with a median of 1.88 years. The mean duration of ERT was 3.7 (+/- 3.01) years, with a median of 3.05 years.

RESULTS

Hot flashes were relieved in 206 of 223 women (92%), dyspareunia/vaginal dryness in 149 of 167 women (89%), and reactive depression/anxiety/mood change in 111 of 126 women (88%). Univariate analysis demonstrated no statistical differences between the groups for age, stage, pathology at diagnosis, progesterone receptor status, local therapy, breast at risk, prior chemotherapy, and duration of follow-up. The ERT group was more likely to be estrogen receptor negative (P = 0.01), to have received prior ERT (P < 0.001), and to have received no adjuvant tamoxifen (P < 0.001). There was no significant difference between the ERT and control groups in ipsilateral primary/recurrence (5/155 v 5/143; P = 0.85), contralateral breast cancers (10/258 v 9/260; P = 0.99), or systemic metastasis (8/277 v 15/277; P = 0.13). Noncause-specific deaths in the control group numbered 15 (of 277), and in the ERT group, 7 (of 277) (P = 0.03). Overall survival favored the ERT group (P = 0.02).

CONCLUSIONS

In these selected patients, ERT relieved estrogen deficiency symptoms and did not increase the rate or time to an ipsilateral recurrence/new primary, contralateral new primary, local-regional recurrence, or systemic metastases.

Hormone replacement therapy after a diagnosis of breast cancer: cancer recurrence and mortality

OBJECTIVE

To determine whether hormone replacement therapy (HRT) after treatment for breast cancer is associated with increased risk of recurrence and mortality.

DESIGN

Retrospective observational study.

PARTICIPANTS AND SETTING

Postmenopausal women diagnosed with breast cancer and treated by five Sydney doctors between 1964 and 1999.

OUTCOME MEASURES

Times from diagnosis to cancer recurrence or new breast cancer, to death from all causes and to death from primary tumour were compared between women who used HRT for menopausal symptoms after diagnosis and those who did not. Relative risks (RRs) were determined from Cox regression analyses, adjusted for patient and tumour characteristics.

RESULTS

1122 women were followed up for 0-36 years (median, 6.08 years); 154 were lost to follow-up. 286 women used HRT for menopausal symptoms for up to 26 years (median, 1.75 years). Compared with non-users, HRT users had reduced risk of cancer recurrence (adjusted relative risk [RR], 0.62; 95% CI, 0.43-0.87), all-cause mortality (RR, 0.34; 95% CI, 0.19-0.59) and death from primary tumour (RR, 0.40; 95% CI, 0.22-0.72). Continuous combined HRT was associated with a reduced risk of death from primary tumour (RR, 0.32; 95% CI, 0.12-0.88) and all-cause mortality (RR, 0.27; 95% CI, 0.10-0.73).

CONCLUSION

HRT use for menopausal symptoms by women treated for primary invasive breast cancer is not associated with an increased risk of breast cancer recurrence or shortened life expectancy.