Estrogen therapy after breast cancer diagnosis and breast cancer mortality risk

Vaginal estrogen use in breast cancer survivors: a systematic review and meta-analysis of recurrence and mortality risks

OBJECTIVE

To assess the risk of breast cancer recurrence, breast cancer-specific mortality, and overall mortality for breast cancer survivors receiving vaginal estrogen therapy for genitourinary syndrome of menopause.

DATA SOURCES

From the inception of each database to April 6th, 2024, a systematic literature search was conducted in Google Scholar, PubMed, EMBASE, CINAHL, NCBI, and Science Direct. A secondary search was conducted on September 26th, 2024 utilizing Google Scholar, PubMed, EMBASE, CINAHL, and Science Direct.

STUDY ELIGIBILITY CRITERIA

We identified studies that reported on breast cancer recurrence defined per individual review criteria and considered both local and distant recurrence.

STUDY APPRAISAL AND SYNTHESIS METHODS

Three reviewers evaluated studies with eligibility criteria in mind. Breast cancer recurrence was the primary outcome. The secondary outcomes included: breast cancer mortality and overall mortality. Pooled unadjusted odds ratios with 95% confidence intervals were calculated using a random-effects model. We assessed the 95% prediction intervals to calculate the likely range within which we can expect to observe future individual values, based on a current model or dataset. We calculated the fragility index to evaluate the robustness of the pooled estimates.

RESULTS

Of 5522 articles identified, 8 observational studies were included in this meta-analysis. The use of vaginal estrogen in patients with a history of breast cancer was not associated with an increased risk of breast cancer recurrence (6 articles, 24,060 patients, odds ratio, 0.48; 95% confidence interval, 0.23-0.98). There was no increase in the risk of breast cancer mortality (4 articles, 61,695 patients, odds ratio 0.60; 95% confidence interval 0.18-1.95). Lastly, there was no increase in overall mortality with use of vaginal estrogen in breast cancer survivors (5 articles 59,724, odds ratio 0.46; 95% confidence interval 0.42-0.49).

CONCLUSION

The use of vaginal estrogen in patients with a history of breast cancer does not appear to be associated with an increased risk of breast cancer recurrence, breast cancer-specific mortality, or overall mortality.

Safety of topical estrogen therapy during adjuvant endocrine treatment among patients with breast cancer: A meta-analysis based expert panel discussion

IMPORTANCE

Endocrine treatments, such as Tamoxifen (TAM) and/or Aromatase inhibitors (AI), are the adjuvant therapy of choice for hormone-receptor positive breast cancer. These agents are associated with menopausal symptoms, adversely affecting drug compliance. Topical estrogen (TE) has been proposed for symptom management, given its' local application and presumed reduced bioavailability, however its oncological safety remains uncertain.

OBJECTIVE

The present systematic review, meta-analysis and expert panel review aimed to evaluate the strength of the available evidence on the risk of recurrence and mortality when TE is utilised in congruence with TAM or AI treatment, among BC survivors.

DATA SOURCES

Six databases and two prospective registers, were interrogated from inception to January 3rd, 2024. Search terms were Breast cancer AND Hormone replacement therapy AND topical/vaginal oestrogen AND recurrence/mortality.

STUDY SELECTION

All study designs reporting the use vs. non-use of TE in breast cancer survivors receiving adjuvant endocrine treatment were included. Six observational studies were deemed eligible for inclusion.

DATA EXTRACTION AND SYNTHESIS

Sources of heterogeneity were explored using subgroup analysis by risk of bias, median follow-up period, node positivity and menopausal status. Trial sequential analysis was performed to quantify outcome reliability. A global expert panel was called to deliberate on the data, pinpoint areas of limited understanding, and determine the most important areas for future research.

MAIN OUTCOMES AND MEASURES

Risk ratio effect sizes (RR) and corresponding 95 % Confidence Intervals (CI) of breast cancer recurrence and mortality in survivors on endocrine treatment (TAM and/or AI) exposed to TE were reported. Expert panel appraisal of meta-analysis evidence with definition of current knowledge gaps and future research aims.

RESULTS

In 38 050 female patients receiving adjuvant endocrine treatment, of whom 1805 had been exposed to TE, TE exposure of those on AI, did not increase all-cause mortality (RR 0.99 [95 %CI 0.58, 1.69], I2 = 81 %, P = 0.96; moderate GRADE certainty). However, such exposure may convey an increased risk of recurrence (RR 2.51 [95 % CI 1.10, 5.72], I2 = 9 %, P = 0.03; low-GRADE certainty). Exposure to TE during TAM did not increase either recurrence risk or all-cause mortality. Clinical factors such as lymph node positivity at the time of diagnosis and menopausal status and follow-up time appeared to be significant confounders.

CONCLUSIONS AND RELEVANCE

The use of TE does not appear to increase either recurrence or mortality risk among BC survivors treated with TAM. An increased recurrence risk, without an increase in mortality, cannot be ruled out when TE is used during AI.

Analysis of Single Nucleotide Polymorphisms (SNPs) rs2234693 and rs9340799 of the ESR1 Gene and the Risk of Breast Cancer

BACKGROUND/AIM

The aim of this study was to analyze rs2234693 and rs9340799 polymorphisms of the ESR1 gene in the context of breast cancer risk in Polish patients.

MATERIALS AND METHODS

The study involved a group of 117 patients with breast cancer and 106 controls. The analyses were carried out using the polymerase chain reaction - restriction fragments length polymorphism technique.

RESULTS

The presence of the CC genotype in rs2234693 more than doubled the risk of breast cancer (p=0.04), whereas the presence of the TT genotype in rs2234693 significantly reduced the risk of developing this type of cancer (p=0.0002). The presence of the GG genotype in rs9340799 more than doubled the risk of breast cancer (p=0.04), which was confirmed by the analysis of the recessive model (p=0.04).

CONCLUSION

The polymorphisms rs2234693 and rs9340799 of the ESR1 gene may be associated with the risk of breast cancer among Polish women.

Oncology: What You May Have Missed in 2023

Advances in oncology treatment methods have improved outcomes and quality of life for patients with cancer. However, care of these patients can be complex, and the contribution of physicians from different specialties is crucial. This article highlights important publications from 2023 on topics across a wide spectrum relating to the management of oncology patients. The literature was screened for significant new evidence that is relevant to internal medicine specialists and subspecialists whose focus is not oncology. Two articles address the importance of social interventions targeting end-of-life care for low-income and minority patients and the well-being of caregivers. Two additional articles address screening considerations in patients at risk for colorectal and lung cancer. Two more articles address safe use of hormone-related therapies to treat symptoms of menopause and prevent disease recurrence or progression in patients diagnosed with noninvasive breast neoplasia. Finally, several articles were included on topics related to COVID-19 vaccination in patients with cancer, use of cannabinoids for cancer pain control, chronic autoimmune adverse effects related to use of immune checkpoint inhibitors, and the incidence of second primary neoplasms.

Vaginal Estrogen Therapy Use and Survival in Females With Breast Cancer

Importance

Genitourinary syndrome of menopause can be treated with vaginal estrogen therapy. However, there are concerns about the safety of vaginal estrogen therapy in patients with breast cancer.

Objective

To determine whether the risk of breast cancer-specific mortality was higher in females with breast cancer who used vaginal estrogen therapy vs females with breast cancer who did not use hormone replacement therapy (HRT).

Design, Setting, and Participants

This cohort study analyzed 2 large cohorts, one each in Scotland and Wales, of females aged 40 to 79 years with newly diagnosed breast cancer. These population-based cohorts were identified from national cancer registry records from 2010 to 2017 in Scotland and from 2000 to 2016 in Wales and were followed up for breast cancer-specific mortality until 2020. Females were excluded if they had a previous cancer diagnosis (except nonmelanoma skin cancer). Data analysis was performed between August 2022 and August 2023.

Exposure

Use of vaginal estrogen therapy, including vaginal tablets and creams, was ascertained from pharmacy dispensing records of the Prescribing Information System for the Scotland cohort and from general practice prescription records for the Wales cohort.

Main Outcomes and Measures

The primary outcome was time to breast cancer-specific mortality, which was obtained from national mortality records. Time-dependent Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% CIs for breast cancer-specific mortality, comparing vaginal estrogen therapy users with HRT nonusers and adjusting for confounders, including cancer stage and grade.

Results

The 2 cohorts comprised 49 237 females with breast cancer (between 40 and 79 years of age) and 5795 breast cancer-specific deaths. Five percent of patients with breast cancer used vaginal estrogen therapy after breast cancer diagnosis. In vaginal estrogen therapy users compared with HRT nonusers, there was no evidence of a higher risk of breast cancer-specific mortality in the pooled fully adjusted model (HR, 0.77; 95% CI, 0.63-0.94).

Conclusions and Relevance

Results of this study showed no evidence of increased early breast cancer-specific mortality in patients who used vaginal estrogen therapy compared with patients who did not use HRT. This finding may provide some reassurance to prescribing clinicians and support the guidelines suggesting that vaginal estrogen therapy can be considered in patients with breast cancer and genitourinary symptoms.

Efficacy of Two Laser Treatment Strategies for Breast Cancer Survivors With Genitourinary Syndrome of Menopause

Background A typical symptom of patients with genitourinary syndrome of menopause (GSM) is dyspareunia. Dyspareunia has been thought to be caused by vaginal dryness. In recent years, a survey of breast cancer survivors (BCS) with GSM has shown that para-hymen is the most painful. Dyspareunia and superficial vulvar pain (vulvodynia) may be closely linked. A recent study showed that vulvodynia is very common in BCS. Therefore, we believe treatment targeting the vagina and the vulva is necessary for pain in BCS with GSM. We hypothesized that treating both the vagina and the vulva would solve the problem of BCS with GSM. We compared the vaginal erbium SMOOTH mode laser (VEL) and neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser (VEL+Nd:YAG) combination treatment over time. This study explores therapeutic targets for pain in BCS with GSM. Methodology This retrospective, case-control study targeted sexually active BCS who reported GSM with vulvodynia and dyspareunia. After all women enrolled in the VEL treatment group had completed treatment, we treated women enrolled in the VEL+Nd:YAG treatment group. A total of 256 women who received either VEL+Nd:YAG or VEL were enrolled. Propensity score (PS)-matching analysis was used to compare two-year postoperative data retrospectively. The PS-matching results registered 102 patients in the VEL+Nd:YAG group and 102 patients in the VEL group. Symptoms were assessed using the visual analog scale (VAS) for vulvodynia before and after laser treatment for one, three, six, 12, and 24 months after completion. As a preliminary study, the vulvodynia swab test confirmed the causative location of dyspareunia. Moreover, the Female Sexual Function Index (FSFI) and Vaginal Health Index Score (VHIS) were assessed. FSFI and VHIS were treated as supplement research because the conditions were unmet. Results In the vulvodynia swab test, dyspareunia, and para-hymen (especially at 4 o'clock and 9 o'clock), all felt pain, and only a few felt pain in the vagina and labia. FSFI improved significantly in the VEL+Nd:YAG group and persisted for two years. VHIS improved equally in both groups and was not significantly different. After the first laser application, the VEL+Nd:YAG and the VEL groups showed sustained efficacy and safety in vulvodynia. Baseline VAS scores (8.74 ± 0.72 vs. 8.79 ± 0.74; p = 0.564) were similar in both groups. Both groups had a significant (p < 0.001) decrease in the VAS score. The VAS values in the VEL+Nd:YAG group and the VEL group decreased from the pretreatment to 3.79 ± 0.63 (p < 0.001 vs. baseline) and 5.56 ± 0.89 (p < 0.001 vs. baseline) after the third treatments, respectively. After 24 months, the VAS value in the VEL+Nd:YAG group and the VEL group was at 4.43 ± 1.38 (p < 0.001 vs. baseline) and 5.56 ± 0.89 (p < 0.001 vs. baseline), respectively. The side effects in both groups were short-term and minor. Conclusions Both VEL+NdYAG and VEL effectively and safely treat GSM dyspareunia and vulvodynia in BCS. Comparing the two groups, we confirmed that VEL+Nd:YAG treatment of the vaginal vestibule and vaginal opening reduced superficial vulvar pain more effectively, extensively, and over a longer period than VEL. The results of the vulvodynia swab test, FSFI, and VHIS suggest that the vulva and the vagina are important therapeutic targets for pain in BCS with GSM. The importance of treating the vulvar area for superficial pain and dyspareunia in GSM has been emphasized.