Suppression of ovarian function in combination with an aromatase inhibitor as treatment for advanced breast cancer in pre-menopausal women

Ovarian Function Suppression in Premenopausal Women with Concurrent Endocrine Therapy Use

INTRODUCTION

Almost 20% of patients receiving ovarian function suppression (OFS) and endocrine therapy (ET) for breast cancer treatment had inadequate OFS within the first year of treatment. Few studies have explored the long-term effectiveness of OFS to maintain estrogen suppression.

PATIENTS AND METHODS

This retrospective, single institution study examined premenopausal women with early-stage breast cancer undergoing treatment with OFS and ET. The primary endpoint was the percentage of patients with inadequate ovarian suppression (estradiol ≥10 pg/mL) during OFS cycle 2 or later. The secondary endpoint was the percentage of patients with inadequate ovarian suppression within the first cycle after OFS initiation. Differences in age, body mass index (BMI), and previous chemotherapy use were summarized via multivariable logistic regression.

RESULTS

Of the 131 patients included in the analysis, 35 (26.7%) lacked adequate suppression during OFS cycle 2 or later cycles. Patients with adequate suppression throughout treatment were more likely to be older (odds ratio [OR] 1.12 [95% CI, 1.05-1.22], P = .02), have a lower BMI (OR 0.88 [95% CI, 0.82-0.94], P < .001), and have received chemotherapy (OR 6.30 [95% CI, 2.06-20.8], P = .002). A total of 20 of 83 patients (24.1%) had an inadequately suppressed estradiol level within 35 days of OFS initiation.

CONCLUSION

This "real world" cohort demonstrates that estradiol concentrations above the postmenopausal range of the assay are frequently detected, including more than 1 year after the start of OFS. Additional research is needed to establish estradiol monitoring guidelines and optimal degree of ovarian suppression.

Breast cancer and incident cardiovascular events: A systematic analysis at the nationwide level

BACKGROUND

Breast cancer (BC) is one of the most common cancers worldwide, and the treatments are frequently cardiotoxic. Whether BC is associated with a higher risk of cardiovascular events is a matter of debate. We evaluated the associations among BC and incident cardiovascular events in a contemporary population.

METHODS

All female patients discharged from French hospitals in 2013 with at least 5 years of follow-up and without a history of major adverse cardiovascular event (myocardial infarction [MI], heart failure [HF], ischaemic stroke or all-cause death, and MACE-HF, which includes cardiovascular death, MI, ischaemic stroke or HF) or cancer (except BC) were identified. After propensity score matching, patients with BC were matched 1:1 with patients with no BC. Hazard ratios (HRs) for cardiovascular events during follow-up were adjusted on age, sex and smoking status at baseline.

RESULTS

1,795,759 patients were included, among whom 64,480 (4.3%) had history of BC. During a mean follow-up of 5.1 years, matched female patients with BC had a higher risk of all-cause death (HR 3.55, 95% confidence interval [CI]: 3.47-3.64), new-onset HF (HR 1.08, 95% CI 1.04-1.11), major bleeding (HR 1.43, 95% CI 1.36-1.49), MACE-HF (HR 1.07, 95% CI 1.04-1.11) and net adverse clinical events (NACE) including all-cause death, MI, ischaemic stroke, HF or major bleeding (HR 2.53, 95% CI 2.48-2.58) compared with those with no BC. By contrast, risks were not higher for cardiovascular death (HR 0.94, 95% CI 0.88-1.00) and were lower for MI (HR 0.81, 95% CI 0.75-0.88) and ischaemic stroke (HR 0.85, 95% CI 0.79-1.11).

CONCLUSIONS

In a large and contemporary analysis of female patients seen in French hospitals, women with history of breast cancer had a higher risk of all-cause mortality, new-onset heart failure and major bleeding compared to a matched cohort of women without breast cancer. In contrast, they have a reduced risk of cardiovascular mortality, MI and stroke.

Optimizing treatment selection, and sequencing decisions for Management of HR-Positive, HER2-Negative advanced breast cancer - Proceedings from breast cancer expert group meeting

PURPOSE

The therapeutic landscape of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) has evolved considerably with the introduction of newer targeted agents and their combinations with endocrine therapies. In this scenario, optimizing treatment selection and sequencing is daunting for clinicians. The purpose of this review is to provide evidence-based answers to key clinical questions on treatment selection and sequencing for the management of HR + HER2 - mBC.

DESIGN

A panel of nine key opinion leaders from Argentina, Brazil, Colombia, Mexico, Moscow, Singapore, South Korea, Taiwan, and UAE convened in October 2018. They reviewed the literature and formulated answers to clinical questions on optimizing the management of HR + HER2 - mBC.

RESULTS

Evidence-based answers were formulated for: (1) optimal initial treatment choice; (2) ovarian function suppression, optimal endocrine partner, and role of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors (in premenopausal women); (3) better first-line standard of care than aromatase inhibitors; (4) preferred second-line treatment; (5) treatment of oligometastatic disease; (6) factors influencing first-line single-agent endocrine therapy choice; (7) influence of endocrine resistance on treatment selection; (8) optimal maintenance regimen in visceral crisis; and (9) need for a breast cancer registry for patients with HR + HER2 - mBC. The panel also proposed a treatment-sequencing algorithm for the management of HR + HER2 - mBC.

CONCLUSION

The current article will serve as a comprehensive guide for optimizing the management of HR + HER2 - mBC. The proposed breast cancer registry will help identify unmet needs and develop strategic regional policies to help improve access to optimized care for HR + HER2 - mBC.

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.

Breast cancer in adolescents and young adults

Breast cancer is the most common cancer of adolescents and young adult (AYA) women aged 15 to 39 years, accounting for 5.6% of all invasive breast cancer in women. In comparison with older women, AYAs are more likely to have familial cancer predisposition genes, larger breast tumors, unfavorable biological characteristics, distant metastatic disease at diagnosis, and adverse outcome. Endocrine therapy and some chemotherapy recommendations differ between young and older women. AYAs require coordinated multidisciplinary care, treatment regimens that minimize late effects such as premature menopause and osteoporosis, and proactive management of psychological and sexual health during and after cancer treatment.

Endocrine Therapy in Premenopausal Hormone Receptor Positive/Human Epidermal Growth Receptor 2 Negative Metastatic Breast Cancer: Between Guidelines and Literature

There is growing interest in the endocrine treatment (ET) of premenopausal women with hormone receptor positive (HR+) metastatic breast cancer (MBC). This review summarizes available data on endocrine therapy for this patient subset and aims to define the most appropriate treatment approach. The combination of luteinizing hormone-releasing hormone (LHRH) agonists plus tamoxifen seems effective and safe and is considered as being superior to either approach alone; still, single-agent therapy remains an acceptable treatment option. Due to their mechanism of action, aromatase inhibitors alone are not suitable for the treatment of premenopausal patients, but the combination with LHRH agonists may result in excellent disease control. Fulvestrant, in conjunction with LHRH agonists, also yields interesting results regarding clinical benefit rate and time to progression; currently, other orally available selective estrogen receptor downregulators are under clinical evaluation. Recently, targeted drugs have been added to ET in order to reverse endocrine resistance, but only limited information regarding their activity in premenopausal patients is available. The cyclin dependent kinase 4 and 6 inhibitor palbociclib when combined with fulvestrant and LHRH agonists was shown to prolong progression-free survival over endocrine therapy alone in pretreated patients; similar results were obtained with the addition of abemacicilib or ribociclib to endocrine therapy. Currently, activity of the mammalian target of rapamycin inhibitor everolimus in combination with letrozole and goserelin is under assessment in premenopausal patients after progression on tamoxifen (MIRACLE trial).

IMPLICATIONS FOR PRACTICE

This review provides clinicians with an overview on the available data regarding endocrine treatment of hormone receptor positive (HR+) metastatic breast cancer (MBC) in premenopausal women and summarizes the treatment options available in routine clinical practice. Knowledge of an up-to-date therapeutic approach in women with premenopausal HR+ MBC will lead to better disease management, thereby improving disease control and quality of life while minimizing side effects.

Targeted Therapy for Premenopausal Women with HR+, HER2- Advanced Breast Cancer: Focus on Special Considerations and Latest Advances

The incidence of advanced breast cancer in premenopausal women is increasing, and breast cancer in younger women is often more aggressive and has a worse prognosis compared with breast cancer in older women. Premenopausal women with hormone receptor-positive (HR⁺) breast cancer are frequently under-represented in clinical trials, and treatment strategies in the premenopausal setting are usually extrapolated from data from postmenopausal patients, with the addition of ovarian function suppression to endocrine therapy in HR⁺ disease. However, the underlying biology of breast cancer in premenopausal women can be different from postmenopausal women, and treatment strategies should ideally be specifically tested in premenopausal patients. Recent phase III trials have now investigated cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in premenopausal patients with HR⁺, HER2^- advanced breast cancer: Palbociclib and abemaciclib have been tested in a subset of premenopausal patients in the PALOMA-3 and MONARCH-2 studies, and ribociclib has been tested in the phase III MONALEESA-7 trial, which was entirely dedicated to premenopausal women. This comprehensive review summarizes the differences in the biology of HR⁺, HER2^- breast cancer in the premenopausal population compared with the postmenopausal population; discusses special considerations for treatment of premenopausal women; and reviews the evidence from clinical trials investigating endocrine therapy, other targeted treatments, and ovarian function suppression in the HR⁺, HER2^- advanced breast cancer setting. Clin Cancer Res; 24(21); 5206-18. ©2018 AACR.

Aromatase inhibitors in premenopausal women with breast cancer: the state of the art and future prospects

Approximately 11% of patients with breast cancer (bca) are diagnosed before menopause, and because in most of those patients the tumour expresses a hormone receptor, treatment with endocrine interventions can be applied in any setting of disease (early or advanced). In the past, hormonal treatment consisted only of the estrogen receptor modulator tamoxifen, associated with luteinizing hormone-releasing hormone (lhrh); more recently, aromatase inhibitors (ais) have come into widespread use. The ais interfere with the last enzymatic step of estrogen synthesis in which androgens are converted into estrogens. Initially, the ais were used alone in postmenopausal patients to prevent disease recurrence, but together with lhrh analogs, they can be used in premenopausal patients to produce better estrogen suppression than can be achieved with tamoxifen plus a lhrh analog. Using a systematic review of the scientific literature (prospective and retrospective studies), we set out to assess the efficacy of ais compared with other endocrine therapy in various disease settings (neoadjuvant, adjuvant, metastatic).

Metastatic Breast Cancer Treated with Lapatinib with a Prolonged Benefit: A Case Report and a Review of Therapeutic Options Available

A 53-year-old woman was treated, after trastuzumab progression of HER2-positive metastatic disease, with capecitabine plus lapatinib and subsequently with lapatinib alone. To date, she has had persistent remission of disease since 2009.

Defining the optimal sequence for the systemic treatment of metastatic breast cancer

Metastatic breast cancer is a heterogeneous disease that presents in varying forms, and a growing number of therapeutic options makes it difficult to determine the best choice in each particular situation. When selecting a systemic treatment, it is important to consider the medication administered in the previous stages, such as acquired resistance, type of progression, time to relapse, tumor aggressiveness, age, comorbidities, pre- and post-menopausal status, and patient preferences. Moreover, tumor genomic signatures can identify different subtypes, which can be used to create patient profiles and design specific therapies. However, there is no consensus regarding the best treatment sequence for each subgroup of patients. During the SABCC Congress of 2014, specialized breast cancer oncologists from referral hospitals in Europe met to define patient profiles and to determine specific treatment sequences for each one. Conclusions were then debated in a final meeting in which a relative degree of consensus for each treatment sequence was established. Four patient profiles were defined according to established breast cancer phenotypes: pre-menopausal patients with luminal subtype, post-menopausal patients with luminal subtype, patients with triple-negative subtype, and patients with HER2-positive subtype. A treatment sequence was then defined, consisting of hormonal therapy with tamoxifen, aromatase inhibitors, fulvestrant, and mTOR inhibitors for pre- and post-menopausal patien ts; a chemotherapy sequence for the first, second, and further lines for luminal and triple-negative patients; and an optimal sequence for treatment with new antiHER2 therapies. Finally, a document detailing all treatment sequences, that had the agreement of all the oncologists, was drawn up as a guideline and advocacy tool for professionals treating patients with this disease.

Endocrine Therapy for Hormone Receptor-Positive Metastatic Breast Cancer: American Society of Clinical Oncology Guideline

PURPOSE

To develop recommendations about endocrine therapy for women with hormone receptor (HR) -positive metastatic breast cancer (MBC).

METHODS

The American Society of Clinical Oncology convened an Expert Panel to conduct a systematic review of evidence from 2008 through 2015 to create recommendations informed by that evidence. Outcomes of interest included sequencing of hormonal agents, hormonal agents compared with chemotherapy, targeted biologic therapy, and treatment of premenopausal women. This guideline puts forth recommendations for endocrine therapy as treatment for women with HR-positive MBC.

RECOMMENDATIONS

Sequential hormone therapy is the preferential treatment for most women with HR-positive MBC. Except in cases of immediately life-threatening disease, hormone therapy, alone or in combination, should be used as initial treatment. Patients whose tumors express any level of hormone receptors should be offered hormone therapy. Treatment recommendations should be based on type of adjuvant treatment, disease-free interval, and organ function. Tumor markers should not be the sole criteria for determining tumor progression; use of additional biomarkers remains experimental. Assessment of menopausal status is critical; ovarian suppression or ablation should be included in premenopausal women. For postmenopausal women, aromatase inhibitors (AIs) are the preferred first-line endocrine therapy, with or without the cyclin-dependent kinase inhibitor palbociclib. As second-line therapy, fulvestrant should be administered at 500 mg with a loading schedule and may be administered with palbociclib. The mammalian target of rapamycin inhibitor everolimus may be administered with exemestane to postmenopausal women with MBC whose disease progresses while receiving nonsteroidal AIs. Among patients with HR-positive, human epidermal growth factor receptor 2-positive MBC, human epidermal growth factor receptor 2-targeted therapy plus an AI can be effective for those who are not chemotherapy candidates.

Twelve-Month Estrogen Levels in Premenopausal Women With Hormone Receptor-Positive Breast Cancer Receiving Adjuvant Triptorelin Plus Exemestane or Tamoxifen in the Suppression of Ovarian Function Trial (SOFT): The SOFT-EST Substudy

PURPOSE

To describe estradiol (E2), estrone (E1), and estrone sulfate (E1S) levels during the first year of monthly triptorelin plus exemestane or tamoxifen and to assess possible suboptimal suppression while receiving exemestane plus triptorelin.

PATIENTS AND METHODS

Premenopausal patients with early breast cancer on the Suppression of Ovarian Function Trial who selected triptorelin as the ovarian suppression method and were randomly assigned to exemestane plus triptorelin or tamoxifen plus triptorelin were enrolled until the target population of 120 patients was reached. Blood sampling time points were 0, 3, 6, 12, 18, 24, 36, and 48 months. Serum estrogens were measured with a highly sensitive and specific assay. This preplanned 12-month analysis evaluated E2, E1, E1S, follicle-stimulating hormone, and luteinizing hormone levels in all patients and the proportion of patients with E2 levels greater than 2.72 pg/mL at any time point during treatment with exemestane plus triptorelin.

RESULTS

One hundred sixteen patients (exemestane, n = 86; tamoxifen, n = 30; median age, 44 years; median E2, 51 pg/mL; 55% prior chemotherapy) started triptorelin and had one or more samples drawn. With exemestane plus triptorelin, median reductions from baseline E2, E1, and E1S levels were consistently ≥ 95%, resulting in significantly lower levels than with tamoxifen plus triptorelin at all time points. Among patients on exemestane plus triptorelin, 25%, 24%, and 17% had an E2 level greater than 2.72 pg/mL at 3, 6, and 12 months, respectively. Baseline factors related to on-treatment E2 level greater than 2.72 pg/mL were no prior chemotherapy (P = .06), higher body mass index (P = .05), and lower follicle-stimulating hormone and luteinizing hormone (each P < .01).

CONCLUSION

During the first year, most patients on exemestane plus triptorelin had E2 levels below the defined threshold of 2.72 pg/mL, consistent with levels reported in postmenopausal patients on aromatase inhibitors, but at each time point, at least 17% of patients had levels greater than the threshold.

Phase II Trial of Goserelin and Exemestane Combination Therapy in Premenopausal Women With Locally Advanced or Metastatic Breast Cancer

A promising option as the treatment of choice for premenopausal patients with locally advanced or metastatic breast cancer (MBC) could be the combination of a luteinizing hormone-releasing hormone analog and an aromatase inhibitor. However, no prospective studies on the efficacy of goserelin with exemestane in locally advanced or MBC premenopausal breast cancer patients have been reported.We present the phase II trial of goserelin plus exemestane in a total of 44 premenopausal women with locally advanced or MBC. All patients received a subcutaneous injection of 3.6 mg goserelin every 4 weeks along with 25 mg exemestane daily. The primary end point was progression-free survival (PFS). The second end point included overall survival (OS), objective response rate (ORR), duration of response (DOR), and clinical benefit rate (CBR) based on complete response (CR), partial response (PR), or stable disease (SD) for ≥6 months.The median PFS was 13 months (range: 2-42 months). The median DOR was 8 months (range: 2-40 months). Two patients achieved CR (4.5%), and 15 patients experienced PR (34.1%). Fifteen patients (34.1%) had SD ≥6 months. The ORR was 38.6%, and the CBR was 65.9%. Primary progressive disease occurred in 15 patients (34.1%). Five patients (11.4%) died during the study period. Because a few patients have died, the median OS has not been reached. Drug therapy was well tolerated. The most frequent grade-3 adverse events were arthralgia (18.2%), skin rash (6.8%), and myalgia (4.5%). No participants withdrew from the study due to drug toxicity.This study suggested that goserelin and exemestane might be highly effective and well-tolerated regimens in premenopausal women with hormone-responsive, locally advanced or MBC.

Clinical utility of exemestane in the treatment of breast cancer

Breast cancer is the most prevalent cancer in women, causing a significant mortality worldwide. Different endocrine strategies are available for the treatment of hormone-sensitive breast cancer, including antiestrogen tamoxifen and fulvestrant, as well as third-generation aromatase inhibitors (AIs), such as letrozole, anastrozole, and exemestane. In this review, we will focus on exemestane, its clinical use, and its side effects. Exemestane is a steroidal third-generation AI now used in all treatment settings for breast cancer. In the metastatic disease, it has been extensively investigated as the first-, second-, and further-line treatment and it is now registered for the treatment of postmenopausal women with advanced estrogen-receptor-positive breast cancer whose disease has progressed following antiestrogen therapy. A potential lack of cross-resistance with nonsteroidal AIs has been described, giving additional therapeutic opportunities in sequences of endocrine agents. Exemestane is also approved for the adjuvant treatment of postmenopausal early breast cancer, either as upfront monotherapy for 5 years, as a switch following 2–3 years of tamoxifen, or as extended therapy beyond 5 years of adjuvant treatment. New promising data also showed a beneficial effect in young premenopausal early breast cancer patients, when administered together with ovarian suppression. Interesting results have also emerged when exemestane has been investigated as neodjuvant treatment as well as preventive agent in healthy women at high risk for breast cancer. Exemestane is generally well tolerated, with a side effect profile similar to that of other AIs, including menopausal symptoms, arthralgia, and bone loss. In conclusion, exemestane can be considered an effective and well-tolerated endocrine treatment option for all stages of breast cancer.

Breast cancer: current and future endocrine therapies

Endocrine therapy forms a central modality in the treatment of estrogen receptor positive breast cancer. The routine use of 5 years of adjuvant tamoxifen has improved survival rates for early breast cancer, and more recently has evolved in the postmenopausal setting to include aromatase inhibitors. The optimal duration of adjuvant endocrine therapy remains an active area of clinical study with recent data supporting 10 years rather than 5 years of adjuvant tamoxifen. However, endocrine therapy is limited by the development of resistance, this can occur by a number of possible mechanisms and numerous studies have been performed which combine endocrine therapy with agents that modulate these mechanisms with the aim of preventing or delaying the emergence of resistance. Recent trial data regarding the combination of the mammalian target of rapamycin (mTOR) inhibitor, everolimus with endocrine therapy have resulted in a redefinition of the clinical treatment pathway in the metastatic setting. This review details the current endocrine therapy utilized in both early and advanced disease, as well as exploring potential new targets which modulate pathways of resistance, as well as agents which aim to modulate adrenal derived steroidogenic hormones.

Luteinizing hormone-releasing hormone agonist plus an aromatase inhibitor as second-line endocrine therapy in premenopausal females with hormone receptor-positive metastatic breast cancer

PURPOSE

The aim of the current study was to explore the efficacy and safety of combination therapy using a luteinizing hormone-releasing hormone (LHRH) agonist plus an aromatase inhibitor (AI) as second-line therapy in premenopausal females with hormone receptor (HR)-positive recurrent or metastatic breast cancer (MBC).

METHODS

A retrospective analysis was conducted in patients registered in the breast cancer database of our institution between January 2001 and December 2012. The breast cancer database identified 14 premenopausal patients who had been treated with an LHRH agonist plus AI for HR-positive recurrent or MBC.

RESULTS

Fourteen patients with recurrent breast cancer (N = 10) or metastatic disease at primary diagnosis (N = 4) were included in the present study. All patients had previously been treated with an LHRH agonist plus tamoxifen. The clinical benefit rate was 71.4% and the median TTP was 11 months (95% confidence interval 1.7-20.3 months). One patient discontinued treatment because of liver dysfunction (grade 3).

CONCLUSIONS

The combination of an LHRH agonist plus an AI is a treatment option for premenopausal females with HR-positive MBC that can prolong the chemotherapy-free interval and yield effective disease stabilization.

Endocrine therapy for advanced/metastatic breast cancer

First-line endocrine therapy by estrogen antagonism or suppression of estrogen achieves objective responses (ORs) and clinical benefit (CB) in around 30% and 50% of estrogen receptor-positive metastatic breast cancer patients, respectively. Aromatase inhibitors (AIs) are the most effective treatment in previously untreated postmenopausal women. Tamoxifen is an effective alternative. The optimal endocrine therapy on relapse remains uncertain. Tamoxifen and fulvestrant achieve CB in around 50% of patients and ORs of 10%. CB of exemestane after nonsteroidal AIs is 30% to 50% but ORs are rare. Targeted agents (eg, everolimus) plus endocrine therapy are likely to become increasingly important in overcoming endocrine resistance.

The aromatase inhibitors (plus ovarian function suppression) in premenopausal breast cancer patients: ready for prime time?

Tamoxifen alone or the combination of ovarian function suppression (OFS) and tamoxifen are the mainstay of hormonal therapy in premenopausal women with endocrine-responsive breast cancer. The results of large trials conducted with the third generation of aromatase inhibitors (AIs) in the metastatic, neoadjuvant and adjuvant setting, indicated better outcomes among postmenopausal breast cancer patients with endocrine responsive disease given AIs than among those given tamoxifen. These results supported the investigation of AIs in combination with OFS in premenopausal women with hormone receptor positive breast cancer. In this article we reviewed the efficacy and toxicity data on the use of AIs combined with OFS in premenopausal breast cancer patients in metastatic, neoadjuvant and adjuvant setting. Given the available evidence at the time in metastatic setting for premenopausal patients suitable of endocrine therapy the AI is a viable option, if tamoxifen resistance is proven, although mandates the use of OFS. In neoadjuvant setting the AIs in combination of OFS should not be used outside of a clinical trial. In the adjuvant setting, tamoxifen alone or OFS plus tamoxifen are reasonable options. Despite the lack of conclusive data favoring the combination of tamoxifen plus OFS, this treatment might be a reasonable option for subgroups of patients such as very young patients, OFS alone should nort be considered unless tamoxifen was contraindicated. Similarly, in cases where tamoxifen is contraindicated, AIs as an adjunct to OFS is a treatment option in premenopausal patients. New large randomized studies are required to confirm the role of OFS plus an AI in premenopausal women.

Efficacy of combined therapy of goserelin and letrozole on very young women with advanced breast cancer as first-line endocrine therapy

Breast cancer in young women younger than 35 years old is rare, aggressive and associated with a poor prognosis. Endocrine therapy is a preferred treatment modality in hormone receptor-positive early stage and advanced breast cancer, combined therapy of goserelin and letrozole presents an option for premenopausal women. We reported the efficacy and safety of therapy of goserelin plus letrozole on very young women with advanced breast cancer as first-line endocrine therapy. Thirty-five patients with first diagnosed as advanced breast cancer, age younger than 35 years, were enrolled in the study. All patients received goserelin 3.6 mg by subcutaneous injection every 4 weeks along with letrozole 2.5mg daily by mouth as first-line endocrine therapy. The study endpoints were objective response rate (ORR), clinical benefit (CB), progression-free survival (PFS), overall survival (OS) and toxicity. The median duration of response to the therapy was 21 (range, 10-56) months, and median duration of follow-up was 44 (range, 5-79) months. The ORR was 25.7%, with one complete response (CR, 2.9%) and eight partial response (PR, 22.9%). Twenty-two patients had stable disease at 24 weeks, for a clinical benefit rate of 65.7%. The median PFS was 9.6 (range 5-58) months and median OS was 33 (range 6-72) months. During the therapy and follow-up, no serious toxicities were reported. Combined therapy of goserelin and letrozole appears to be an efficacious and well-tolerated therapy for very young women with advanced breast cancer. Further investigations involving more patients, combination of other therapies and longer follow-up are requisite.

Ovarian function suppression and fulvestrant as endocrine therapy in premenopausal women with metastatic breast cancer

BACKGROUND

Endocrine therapy is the preferred treatment for hormone-receptor (HR) positive metastatic breast cancer. In premenopausal patients, ovarian function suppression with goserelin in combination with anastrozole yielded promising results in phase II studies. Fulvestrant, a pure antioestrogen, yields high rates of disease stabilisation in postmenopausal women. Therefore, we investigated the feasibility and safety of fulvestrant plus goserelin in premenopausal women with HR-positive metastatic breast cancer.

METHODS

Premenopausal patients with metastatic breast cancer eligible for endocrine treatment received fulvestrant 250 mg and goserelin 3.6 mg every four weeks as first- to fourth-line therapy. Clinical benefit rate (CBR; response rate plus disease stabilisation ≥ 6 months) was defined as the primary study end-point. Time to progression (TTP) and overall survival (OS) were estimated using the Kaplan-Meier product limit method.

FINDINGS

Twenty-six patients received treatment as scheduled. 81% were pre-treated with tamoxifen and 69% had received prior aromatase inhibitors in combination with goserelin. The majority of patients (69%) presented with visceral metastases. Complete response was observed in a single patient, partial response in three and disease stabilisation ≥ 6 months in eleven patients, resulting in a CBR of 58%. Median TTP was 6 months (95%confidence interval (CI), 2.4-9.6) and OS 32 months (95%CI, 14.28-49.72), respectively.

INTERPRETATION

Results suggest that the combination of fulvestrant and goserelin offers promising activity in premenopausal patients and further investigation is warranted.

Management of patients with metastatic breast cancer

Hormone treatment is one of the key strategies in the management of metastatic breast cancer. Hormone treatment is one of the key strategies in the management of metastatic breast cancer. Aromatase inhibitors (AI) have been extensively studied in this setting. This section summarizes the key data regarding the use of AI in advanced breast cancer. In postmenopausal women, AI are the first line of treatment for untreated patients, or those who had prior AI treatment and progress after 12 months of adjuvant therapy. A longer disease-free interval and absence of visceral disease is associated with a better response. If tumors recur in less than 12 months, it is recommended that tamoxifen (TAM) or the estrogen-receptor antagonist fulvestrant (FUL) treatment be initiated. In the second-line setting, the best option after progression is the administration of either FUL or TAM. In the third-line setting, reintroduction of AI is considered an acceptable option. In premenopausal women who have not received prior treatment or who have progressed after 12 months following adjuvant treatment, it is recommended to initiate therapy with a combination of TAM and a luteinizing hormone-releasing hormone (LHRH) analog. If there is treatment failure with the use of this combination, megestrol acetate or an LHRH agonist plus an AI may be reasonable alternatives. Intensive research is ongoing to understand the mechanisms of resistance to hormone therapy. In human epidermal growth factor receptor 2 positive-patients, combinations with HER2 antagonists are associated with significant clinical activity.