The role of the addition of ovarian suppression to tamoxifen in young women with hormone-sensitive breast cancer who remain premenopausal or regain menstruation after chemotherapy (ASTRRA): study protocol for a randomized controlled trial and progress

Hormone Receptor-Positive/HER2-Positive Breast Cancer: Hormone Therapy and Anti-HER2 Treatment: An Update on Treatment Strategies

Hormone receptor (HR)-positive/HER2-positive breast cancer represents a distinct subtype expressing estrogen and progesterone receptors with an overexpression of HER2. Approximately 14% of female breast cancer cases are HER2-positive, with the majority being HR-positive. These tumors show a cross-talk between the hormonal and HER2 pathways; the interaction has implications for the treatment options for the disease. In this review, we analyze the biology of HR-positive/HER2-positive breast cancer and summarize the evidence concerning the standard of care options both in neoadjuvant/adjuvant settings and in advanced disease. Additionally, we focus on new trials and drugs for HR-positive/HER2-positive breast cancer and the new entity: HER2-low breast cancer.

Adding Ovarian Suppression to Tamoxifen for Premenopausal Women With Hormone Receptor-Positive Breast Cancer After Chemotherapy: An 8-Year Follow-Up of the ASTRRA Trial

PURPOSE

To determine the updated long-term outcomes of the Addition of Ovarian Suppression to Tamoxifen in Young Women With Hormone-Sensitive Breast Cancer Who Remain Premenopausal or Regain Vaginal Bleeding After Chemotherapy (ASTRRA) trial.

PATIENTS AND METHODS

This study is a post-trial follow-up of the ASTRRA trial, involving 1,483 premenopausal women younger than 45 years treated with definitive surgery after completing adjuvant or neoadjuvant chemotherapy for estrogen receptor-positive breast cancer. Patients were randomly assigned in a 1:1 ratio to complete 5 years of tamoxifen (TAM) alone (TAM-only) or 5 years of TAM with ovarian function suppression (OFS) for 2 years (TAM + OFS). The primary end point was disease-free survival (DFS), and the secondary end point was overall survival (OS).

RESULTS

At 106.4 months of median follow-up, there was a continuous significant reduction in the DFS event rate in the TAM + OFS group. The 8-year DFS rate was 85.4% in the TAM + OFS group and 80.2% in the TAM-only group (hazard ratio [HR], 0.67; 95% CI, 0.51 to 0.87). There were no significant differences in OS between the two groups. The OS rate was 96.5% in the TAM + OFS group and 95.3% in the TAM-only group (HR, 0.78; 95% CI, 0.49 to 1.25).

CONCLUSION

Adding OFS for 2 years to adjuvant TAM with a longer follow-up resulted in consistent DFS benefits, suggesting that adding OFS to TAM should be considered for patients who remain in a premenopausal state or resume ovarian function after chemotherapy.

Adjuvant Endocrine Therapy in Premenopausal Women With Hormone Receptor-Positive Early-Stage Breast Cancer: Risk Stratification in a Real-World Setting

BACKGROUND

Ovarian function suppression (OFS) and hormone therapy (HT) represent an adjuvant option in premenopausal hormone receptor-positive early breast cancer (HR+EBC). The SOFT-TEXT trials showed improved outcomes upon receiving aromatase inhibitors (AIs)/OFS.

METHODS

In order to estimate the magnitude of absolute improvements, we conducted a retrospective study applying composite risk (CR) to 237 premenopausal HR+EBC patients.

RESULTS

Overall, 119 of these received tamoxifen (T)/OFS and 118 received AIs/OFS. The median age was 45 years (ys). After a median follow up of 65 months, recurrence was 6.7% in T patients and 10.2% in AI ones. CR (cutoff: 2.67) and ET duration (five-year cutoff) was found to have a significant impact on DFS. Invasive disease-free survival (IDFS) at 5 ys amounted to 82.9% for a CR>2.67 and 95% with CR

CONCLUSION

In a real-world setting, treatment options for premenopausal patients who are candidates for HT and OFS should take risk status into account. Therefore, every effort should be made to maintain patient adherence to treatment in order to manage toxicities and improve outcomes.

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Key Words

• Adjuvant hormone therapy
• Aromatase inhibitors
• Breast cancer
• Ovarian function suppression
• Tamoxifen

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Affiliation(s)

Raffaella D'Onofrio Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
Claudia Omarini Division of Medical Oncology, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy; Gruppo Oncologico Italiano per la Ricerca Clinica (GOIRC), Parma, Italy
Angela Toss Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy; Department of Oncology and Hematology, Azienda Ospedaliero-Universitaria di Modena, Modena, Italy
Isabella Sperduti Biostatistics Unit, IRCCS Regina Elena National Cancer Institute, Rome, Italy
Federico Piacentini Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy; Gruppo Oncologico Italiano per la Ricerca Clinica (GOIRC), Parma, Italy
Monica Barbolini Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
Laura Cortesi Division of Medical Oncology, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
Elena Barbieri Division of Medical Oncology, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy
Elisa Pettorelli Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
Chiara Chiavelli Department of Oncology and Hematology, Azienda Ospedaliero-Universitaria di Modena, Modena, Italy; Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy
Massimo Dominici Division of Medical Oncology, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy; Department of Oncology and Hematology, Azienda Ospedaliero-Universitaria di Modena, Modena, Italy
Luca Moscetti Division of Medical Oncology, Department of Oncology and Hematology, University Hospital of Modena, Modena, Italy; Gruppo Oncologico Italiano per la Ricerca Clinica (GOIRC), Parma, Italy.

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Ovarian Function Suppression With Luteinizing Hormone-Releasing Hormone Agonists for the Treatment of Hormone Receptor-Positive Early Breast Cancer in Premenopausal Women

Chemotherapy and endocrine therapies are mainstays of treatment for early and advanced hormone receptor-positive (HR+) breast cancer. In premenopausal women with HR+ tumors, the benefits of adding ovarian function suppression (OFS) to endocrine therapy have been debated. Consequently, for many years, tamoxifen monotherapy has been the standard of care for endocrine treatment in the adjuvant setting. Recent studies have, however, provided new evidence that, in some premenopausal patients, OFS in combination with tamoxifen or aromatase inhibitors (AIs) can significantly increase survival versus tamoxifen alone. Luteinizing hormone-releasing hormone agonists (LHRHa), including goserelin, triptorelin, and leuprorelin, achieve OFS through sustained suppression of the release of follicle-stimulating hormone and luteinizing hormone from the pituitary. In turn, this suppresses production and secretion of estradiol, an ovarian hormone that supports cancer cell growth, survival, and proliferation. In this review, we discuss the clinical evidence supporting the addition of LHRHa to adjuvant endocrine therapies, including tamoxifen and AIs, for premenopausal women with breast cancer. We also discuss the role of LHRHa use in combination with adjuvant chemotherapy to preserve ovarian function and fertility in young patients with breast cancer. Finally, we discuss important practical aspects of the use of LHRHa in breast cancer treatment, including side-effects, patient adherence to treatment, and the use of slow-release, long-acting drug formulations.

Five-year changes in ovarian function restoration in premenopausal patients with breast cancer taking tamoxifen after chemotherapy: An ASTRRA study report

BACKGROUND

Adding ovarian function suppression (OFS) after chemotherapy improves survival in young women with moderate- and high-risk breast cancer. Assessment of ovarian function restoration after chemotherapy becomes critical for subsequent endocrine treatment and addressing fertility issues.

PATIENTS AND METHODS

In the adding OFS after chemotherapy trial, patients who resumed ovarian function up to 2 years after chemotherapy were randomised to receive either 5 years of tamoxifen or adding 2 years of OFS with tamoxifen. Ovarian function was evaluated from enrolment to randomisation, and patients who did not randomise because of amenorrhoea for 2 years received tamoxifen and were followed up for 5 years. Prospectively collected consecutive hormone levels (proportion of patients with premenopausal follicle-stimulating hormone [FSH] levels <30 mIU/mL and oestradiol [E2] levels ≥40 pg/mL) and history of menstruation were available for 1067 patients with breast cancer.

RESULTS

Over 5 years of tamoxifen treatment, 69% of patients resumed menstruation and 98% and 74% of patients satisfied predefined ovarian function restoration as per serum FSH and E2 levels, respectively. Menstruation was restored in 91% of patients younger than 35 years at baseline, but in only 33% of 45-year-old patients over 5 years. Among these patients, 41% experienced menstruation restoration within 2 years after chemotherapy and 28% slowly restored menstruation after 2-5 years. Younger age (<35 years) at baseline, anthracycline without taxanes and ≤90 days of chemotherapy were predictors of menstruation restoration.

CONCLUSIONS

During 5 years of tamoxifen treatment after chemotherapy, two-thirds of the patients experienced menstruation restoration, especially patients younger than 35 years. Young age, Adriamycin without taxanes and short duration of chemotherapy appeared to have a positive effect on ovarian reserves in the long term.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00912548.

Current State of the Art in the Adjuvant Systemic Treatment of Premenopausal Patients With Early Breast Cancer

Breast cancer is the most frequent malignancy diagnosed in premenopausal women. In this age group, breast tumors tend to be diagnosed at more advanced stages and to harbor more aggressive biological features. In addition, specific age-related issues including genetic counseling, fertility preservation, impact on social and couple relationships, working life, and management of long-term side effects should be considered highly relevant when managing early breast cancer in premenopausal women. Therefore, the care of these patients is particularly complex and a multidisciplinary approach is mandatory. The present review summarizes the current state of art in the adjuvant systemic treatment of premenopausal women with early breast cancer focusing on the optimal chemotherapy, endocrine therapy, and targeted therapy approaches in this specific patient population.

Ovarian suppression for adjuvant treatment of hormone receptor-positive early breast cancer

BACKGROUND

Approximately 80% of breast cancers amongst premenopausal women are hormone receptor-positive. Adjuvant endocrine therapy is an integral component of care for hormone receptor-positive breast cancer and in premenopausal women includes oestrogen receptor blockade with tamoxifen, temporary suppression of ovarian oestrogen synthesis by luteinising hormone releasing hormone (LHRH) agonists, and permanent interruption of ovarian oestrogen synthesis with oophorectomy or radiotherapy. Recent international consensus statements recommend single-agent tamoxifen or aromatase inhibitors with ovarian function suppression (OFS) as the current standard adjuvant endocrine therapy for premenopausal women (often preceded by chemotherapy). This review examined the role of adding OFS to another treatment (i.e. chemotherapy, endocrine therapy, or both) or comparing OFS to no further adjuvant treatment.

OBJECTIVES

To assess effects of OFS for treatment of premenopausal women with hormone receptor-positive early breast cancer.

SEARCH METHODS

For this review update, we searched the Specialised Register of the Cochrane Breast Cancer Group, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 8), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and ClinicalTrials.gov on 26 September 2019. We screened the reference lists of related articles, contacted trial authors, and applied no language restrictions.

SELECTION CRITERIA

We included all randomised trials assessing any method of OFS, that is, oophorectomy, radiation-induced ovarian ablation, or LHRH agonists, as adjuvant treatment for premenopausal women with early-stage breast cancer. We included studies that compared (1) OFS versus observation, (2) OFS + chemotherapy versus chemotherapy, (3) OFS + tamoxifen versus tamoxifen, and (4) OFS + chemotherapy + tamoxifen versus chemotherapy + tamoxifen.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias and certainty of evidence using the GRADE approach. Hazard ratios (HRs) were derived for time-to-event outcomes, and meta-analysis was performed using a fixed-effect model. The primary outcome measures were overall survival (OS) and disease-free survival (DFS). Toxicity, contralateral breast cancer, and second malignancy were represented as risk ratios (RRs), and quality of life data were extracted when provided.

MAIN RESULTS

This review update included 15 studies involving 11,538 premenopausal women with hormone receptor-positive early breast cancer; these studies were conducted from 1978 to 2014. Some of these treatments are not current standard of care, and early studies did not assess HER2 receptor status. Studies tested OFS versus observation (one study), OFS plus chemotherapy versus chemotherapy (six studies), OFS plus tamoxifen versus tamoxifen (six studies), and OFS plus chemotherapy and tamoxifen versus chemotherapy and tamoxifen (two studies). Of those studies that reported the chemotherapy regimen, an estimated 72% of women received an anthracycline. The results described below relate to the overall comparison of OFS versus no OFS. High-certainty evidence shows that adding OFS to treatment resulted in a reduction in mortality (hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.78 to 0.94; 11 studies; 10,374 women; 1933 reported events). This treatment effect was seen when OFS was added to observation, to tamoxifen, or to chemotherapy and tamoxifen. The effect on mortality was not observed when OFS was added to chemotherapy without tamoxifen therapy (HR 0.95, 95% CI 0.82 to 1.09; 5 studies; 3087 women; median follow-up: range 7.7 to 12.1 years). The addition of OFS resulted in improved DFS (HR 0.83, 95% CI 0.77 to 0.90; 10 studies; 8899 women; 2757 reported events; high-certainty evidence). The DFS treatment effect persisted when OFS was added to observation, to tamoxifen, and to chemotherapy and tamoxifen. The effect on DFS was reduced when OFS was added to chemotherapy without tamoxifen therapy (HR 0.90, 95% CI 0.79 to 1.01; 5 studies; 2450 women). Heterogeneity was low to moderate across studies for DFS and OS (respectively). Evidence suggests that adding OFS slightly increases the incidence of hot flushes (grade 3/4 or any grade; risk ratio (RR) 1.60, 95% CI 1.41 to 1.82; 6 studies; 5581 women; low-certainty evidence, as this may have been under-reported in these studies). Two other studies that could not be included in the meta-analysis reported a higher number of hot flushes in the OFS group than in the no-OFS group. Seven studies involving 5354 women collected information related to mood; however this information was reported as grade 3 or 4 depression, anxiety, or neuropsychiatric symptoms, or symptoms were reported without the grade. Two studies reported an increase in depression, anxiety, and neuropsychiatric symptoms in the OFS group compared to the no-OFS group, and five studies indicated an increase in anxiety in both treatment groups (but no difference between groups) or no difference overall in symptoms over time or between treatment groups. A single study reported bone health as osteoporosis (defined as T score < -2.5); this limited evidence suggests that OFS increases the risk of osteoporosis compared to no-OFS at median follow-up of 5.6 years (RR 1.16, 95% CI 1.10 to 28.82; 2011 women; low-certainty evidence). Adding OFS to treatment likely reduces the risk of contralateral breast cancer (HR 0.75, 95% CI 0.57 to 0.97; 9 studies; 9138 women; moderate-certainty evidence). Quality of life was assessed in five studies; four studies used validated tools, and the fifth study provided no information on how data were collected. Two studies reported worse quality of life indicators (i.e. vaginal dryness, day and night sweats) for women receiving OFS compared to those in the no-OFS group. The other two studies indicated worsening of symptoms (e.g. vasomotor, gynaecological, vaginal dryness, decline in sexual interest, bone and joint pain, weight gain); however these side effects were reported in both OFS and no-OFS groups. The study that did not use a validated quality of life tool described no considerable differences between groups.

AUTHORS' CONCLUSIONS

This review found evidence that supports adding OFS for premenopausal women with early, hormone receptor-positive breast cancers. The benefit of OFS persisted when compared to observation, and when added to endocrine therapy (tamoxifen) or chemotherapy and endocrine therapy (tamoxifen). The decision to use OFS may depend on the overall risk assessment based on tumour and patient characteristics, and may follow consideration of all side effects that occur with the addition of OFS.

Controversies Regarding Ovarian Suppression and Infertility in Early Stage Breast Cancer

A common side effect of chemotherapy in breast cancer is early menopause in premenopausal patients, which is mainly a result of an indirect form of ovarian ablation, and is associated with substantial impairment of quality of life. Suppressing the production of ovarian estrogen has been shown to reduce the recurrence of hormone receptor-positive early breast cancer in premenopausal women, but whether it has an added advantage over tamoxifen is being discussed. Types of permanent ablation of the ovarian function include surgical oophorectomy and radiation-induced ovarian failure. Both are associated with similar response rates in hormone receptor-positive metastatic breast cancer. Medical castration with luteinizing hormone-releasing hormone analogs (LHRHa) has the benefit of being a reversible approach. Another advantage that premenopausal patients who wish to reduce the risk of developing premature ovarian insufficiency induced by chemotherapy may be offered LHRHa irrespective of whether they desire pregnancy and their age at diagnosis. This also helps reduce the risk of menopausal signs and symptoms as well as the loss of bone density in the long-term, which are primary concerns for women. This is of utmost importance to premenopausal women who do not want to conceive after treatment or are not candidates for fertility preservation strategies because of age. It should be emphasized that for women who are interested in fertility preservation, gamete cryopreservation remains the first option, and LHRHa is not an alternative. During chemotherapy, however, temporary ovarian suppression with LHRHa may be given to women who either have no access to a fertility clinic or who have declined chemotherapy or have contraindications.

Impact of ovarian function suppression in premenopausal women with estrogen receptor-positive early breast cancer

PURPOSE OF REVIEW

This manuscript aims at providing an updated overview on the role of adding ovarian function suppression to tamoxifen or an aromatase inhibitor as adjuvant endocrine therapy in premenopausal women with estrogen receptor-positive early breast cancer.

RECENT FINDINGS

Until recently, tamoxifen alone was the only recommended adjuvant treatment option for premenopausal women with estrogen receptor-positive disease. However, recent important evidence has contributed to significantly modify the endocrine treatment landscape in this setting.

SUMMARY

With the only exception of patients with low-risk clinical-pathological features characterized by excellent survival outcomes with tamoxifen alone, the use of ovarian function suppression is to be considered standard of care for most of premenopausal women with estrogen receptor-positive disease. Regarding the choice of its best partner as endocrine agent, the available data suggest that the higher the risk of disease recurrence the larger benefit can be observed with a more profound estrogen deprivation that can be obtained with ovarian function suppression and an aromatase inhibitor as compared to ovarian function suppression and tamoxifen. Despite the significant improvement in our understanding on the role of ovarian function suppression in this setting, several unanswered questions remain and further research efforts are needed in the field.

Improving Adjuvant Endocrine Treatment Tailoring in Premenopausal Women With Hormone Receptor-Positive Breast Cancer

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Revisiting adjuvant ovarian suppression in premenopausal breast cancer patients

Adjuvant ovarian suppression, on addition to chemotherapy, reduces the risk of breast cancer in pre-menopausal women after surgery and adjuvant hormonal therapy. Suppression of Ovarian Function Trial (SOFT) and Tamoxifen and Exemestane Trial (TEXT) showed greater benefit with exemestane in high risk females in comparison to Tamoxifen. Ovarian Function Suppression (OFS) and exemestane became the standard of care, with 30% patients experiencing grade 3 and more side effects. Much higher benefit was seen in high risk group. But there are concerns about incomplete OFS (estrogen escape) with exemestane plus OFS. Updated analysis of TEXT AND SOFT showed better survival benefit with OFS plus Tamoxifen as compared to OFS plus exemestane. Overall survival is a better end point. Should preference be given to Tamoxifen over exemestane? Further research is required to get the final answer.

Treatment of Breast Cancer With Gonadotropin-Releasing Hormone Analogs

Although significant progress has been made in the implementation of new breast cancer treatments over the last three decades, this neoplasm annually continues to show high worldwide rates of morbidity and mortality. In consequence, the search for novel therapies with greater effectiveness and specificity has not come to a stop. Among the alternative therapeutic targets, the human gonadotropin-releasing hormone type I and type II (hGnRH-I and hGnRH–II, respectively) and its receptor, the human gonadotropin-releasing hormone receptor type I (hGnRHR-I), have shown to be powerful therapeutic targets to decrease the adverse effects of this disease. In the present review, we describe how the administration of GnRH analogs is able to reduce circulating concentrations of estrogen in premenopausal women through their action on the hypothalamus–pituitary–ovarian axis, consequently reducing the growth of breast tumors and disease recurrence. Also, it has been mentioned that, regardless of the suppression of synthesis and secretion of ovarian steroids, GnRH agonists exert direct anticancer action, such as the reduction of tumor growth and cell invasion. In addition, we discuss the effects on breast cancer of the hGnRH-I and hGnRH-II agonist and antagonist, non-peptide GnRH antagonists, and cytotoxic analogs of GnRH and their implication as novel adjuvant therapies as antitumor agents for reducing the adverse effects of breast cancer. In conclusion, we suggest that the hGnRH/hGnRHR system is a promising target for pharmaceutical development in the treatment of breast cancer, especially for the treatment of advanced states of this disease.

Adding Ovarian Suppression to Tamoxifen for Premenopausal Breast Cancer: A Randomized Phase III Trial

PURPOSE

The addition of ovarian function suppression (OFS) for 5 years to tamoxifen (TAM) for treatment of premenopausal patients with breast cancer after completion of chemotherapy has beneficial effects on disease-free survival (DFS). This study evaluated the efficacy of adding 2 years of OFS to TAM in patients with hormone receptor-positive breast cancer who remain in a premenopausal state or resume ovarian function after chemotherapy.

PATIENTS AND METHODS

We enrolled 1,483 premenopausal women (age ≤ 45 years) with estrogen receptor-positive breast cancer treated with definitive surgery after completing adjuvant or neoadjuvant chemotherapy. Ovarian function was assessed every 6 months for 2 years since enrollment on the basis of follicular-stimulating hormone levels and vaginal bleeding history. If ovarian function was confirmed to be premenopausal at each visit, the patient was randomly assigned to complete 5 years of TAM alone (TAM-only) group or 5 years of TAM with OFS for 2 years that involved monthly goserelin administration (TAM + OFS) group. DFS was defined from the time of enrollment to the time of the first event.

RESULTS

A total of 1,293 patients were randomly assigned, and 1,282 patients were eligible for analysis. The estimated 5-year DFS rate was 91.1% in the TAM + OFS group and 87.5% in the TAM-only group (hazard ratio, 0.69; 95% CI, 0.48 to 0.97; P = .033). The estimated 5-year overall survival rate was 99.4% in the TAM + OFS group and 97.8% in the TAM-only group (hazard ratio, 0.31; 95% CI, 0.10 to 0.94; P = .029).

CONCLUSION

The addition of 2 years of OFS to TAM significantly improved DFS compared with TAM alone in patients who remained premenopausal or resumed ovarian function after chemotherapy.

Post-chemotherapy serum anti-Müllerian hormone level predicts ovarian function recovery

In the era of precision medicine, the prediction of ovarian function recovery from chemotherapy-induced amenorrhoea using feasible biological markers may be helpful to optimise the treatment strategy for young patients with hormone receptor-positive breast cancer. The purpose of this study was to investigate the accuracy of post-chemotherapy biological markers for predicting the recovery of ovarian function in breast cancer patients of the ASTRRA trial, with chemotherapy-induced amenorrhoea. Using data of 82 participants from a single institution in the ASTRRA trial, the post-chemotherapy serum levels of the anti-Müllerian hormone (AMH), oestradiol, inhibin B and other clinical factors associated with chemotherapy-induced amenorrhoea were evaluated. Recovery of ovarian function was defined by the resumption of menstruation manifested by vaginal bleeding. Fifty-two patients regained menstruation within 55 months after enrolment. In univariate analysis, <40 years of age (P = 0.009), oestradiol ≥37 pg/mL (P = 0.003) or AMH ≥800 pg/mL (P = 0.026) were associated with recovery of menstruation. On multivariate analysis, oestradiol (hazard ratio: 3.171, 95% CI: 1.306–7.699, P = 0.011) and AMH (hazard ratio: 2.853, 95% CI: 1.011–8.046, P = 0.048) remained as significant independent predictors for resumption of menstruation. The diagnostic accuracy of age, oestradiol and AMH in predicting the resumption of menstruation was 38.3, 23.3 and 86.7%, respectively. In conclusion, post-chemotherapy AMH level might be a relatively accurate predictor of the recovery of ovarian function, presented by resumption of menstruation in breast cancer patients with chemotherapy-induced amenorrhoea

Reactivation of cAMP Pathway by PDE4D Inhibition Represents a Novel Druggable Axis for Overcoming Tamoxifen Resistance in ER-positive Breast Cancer

Purpose: Tamoxifen remains an important hormonal therapy for ER-positive breast cancer; however, development of resistance is a major obstacle in clinics. Here, we aimed to identify novel mechanisms of tamoxifen resistance and provide actionable drug targets overcoming resistance.Experimental Design: Whole-transcriptome sequencing, downstream pathway analysis, and drug repositioning approaches were used to identify novel modulators [here: phosphodiesterase 4D (PDE4D)] of tamoxifen resistance. Clinical data involving tamoxifen-treated patients with ER-positive breast cancer were used to assess the impact of PDE4D in tamoxifen resistance. Tamoxifen sensitization role of PDE4D was tested in vitro and in vivo Cytobiology, biochemistry, and functional genomics tools were used to elucidate the mechanisms of PDE4D-mediated tamoxifen resistance.Results: PDE4D, which hydrolyzes cyclic AMP (cAMP), was significantly overexpressed in both MCF-7 and T47D tamoxifen-resistant (TamR) cells. Higher PDE4D expression predicted worse survival in tamoxifen-treated patients with breast cancer (n = 469, P = 0.0036 for DMFS; n = 561, P = 0.0229 for RFS) and remained an independent prognostic factor for RFS in multivariate analysis (n = 132, P = 0.049). Inhibition of PDE4D by either siRNAs or pharmacologic inhibitors (dipyridamole and Gebr-7b) restored tamoxifen sensitivity. Sensitization to tamoxifen is achieved via cAMP-mediated induction of unfolded protein response/ER stress pathway leading to activation of p38/JNK signaling and apoptosis. Remarkably, acetylsalicylic acid (aspirin) was predicted to be a tamoxifen sensitizer using a drug repositioning approach and was shown to reverse resistance by targeting PDE4D/cAMP/ER stress axis. Finally, combining PDE4D inhibitors and tamoxifen suppressed tumor growth better than individual groups in vivoConclusions: PDE4D plays a pivotal role in acquired tamoxifen resistance via blocking cAMP/ER stress/p38-JNK signaling and apoptosis. Clin Cancer Res; 24(8); 1987-2001. ©2018 AACR.