Exemestane as primary treatment of oestrogen receptor-positive breast cancer in postmenopausal women: a phase II trial

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers: from chemotherapy to hormonal therapy, CDK inhibitors, and beyond

INTRODUCTION

Chemotherapy has been traditionally used as neo-adjuvant therapy in breast cancer for down-staging of locally advanced disease in all sub-types. In the adjuvant setting, genomic assays have shown that a significant proportion of ER positive/HER2 negative patients do not derive benefit from the addition of chemotherapy to adjuvant endocrine therapy. An interest in hormonal treatments as neo-adjuvant therapies in ER positive/HER2 negative cancers has been borne by their documented success in the adjuvant setting. Moreover, cytotoxic chemotherapy is less effective in ER positive/HER2 negative disease compared with other breast cancer subtypes in obtaining pathologic complete responses.

AREAS COVERED

Neo-adjuvant therapies for ER positive/HER2 negative breast cancers and associated biomarkers are reviewed, using a Medline survey. A focus of discussion is the prediction of patients that are unlikely to derive extra benefit from chemotherapy and have the highest probabilities of benefiting from hormonal and other targeted therapies.

EXPERT OPINION

Predictive biomarkers of response to neo-adjuvant chemotherapy and hormonal therapies are instrumental for selecting ER positive/HER2 negative breast cancer patients for each treatment. Chemotherapy remains the standard of care for many of those patients requiring neo-adjuvant treatment, but other neo-adjuvant therapies are increasingly used.

Role of Exemestane in the Treatment of Estrogen-Receptor-Positive Breast Cancer: A Narrative Review of Recent Evidence

INTRODUCTION

Breast cancer (BC) is the most common type of cancer diagnosed among women worldwide with an estimated 2.3 million new cases every year. Almost two-thirds of all patients with BC have estrogen receptor-positive (ER+) tumors. In this review, the clinical evidence of exemestane in different treatment settings in ER+ BC is presented and summarized.

SEARCH STRATEGY

A search strategy with the keywords "breast cancer [MeSH Terms]" AND "exemestane [Title/Abstract]" was devised and a search was performed in PubMed.

RESULTS

The efficacy of exemestane in different treatment settings has been established by numerous clinical studies. Exemestane is recommended as an adjuvant treatment in postmenopausal women previously treated with tamoxifen in trials comparing 5 years of tamoxifen with 2-3 years of tamoxifen combined with 2-3 years of exemestane, which proved that treatment with exemestane provided better survival outcomes. Similarly, exemestane could be considered as a safe treatment option for neoadjuvant treatment, prevention of chemotherapy, and treatment of advanced BC either alone or in combination with other targeted therapy drugs in both pre- and postmenopausal women.

CONCLUSION

Exemestane could be considered as a reasonable therapeutic option in the treatment of ER+ BC at any stage in pre- and postmenopausal women.

Neoadjuvant Endocrine Therapy in Clinical Practice: A Review

Importance

In clinical practice, neoadjuvant endocrine therapy (NET) is rarely used despite being an effective treatment modality able to downstage tumors and facilitate breast-conserving surgery.

Observations

Using data from studies conducted since 2000, we provide readers with a critical in-depth review on clinical aspects related to the application of NET in the treatment of hormone receptor (HR)-positive/ERBB2 (formerly HER2)-negative breast cancer. This includes an overview of patient-selection criteria, regimen choice, treatment duration, evaluation of response by imaging, interpretation of pathology after treatment, and surgical considerations. Areas of controversy include the use of gene-expression tests for patient selection, treatment of premenopausal women, surgical management of the axilla after NET, and adjuvant systemic therapy decision-making, including the use of chemotherapy.

Conclusions and Relevance

NET is an optimal treatment modality for a considerable proportion of postmenopausal women diagnosed with HR-positive tumors. The treatment landscape for HR-positive breast cancer is evolving, with novel agents and the growing use of gene expression profiling to define treatment selection. As such, it is likely that NET use will increase and the practical considerations outlined here will become more important.

A system for risk stratification and prioritization of breast cancer surgeries delayed by the COVID-19 pandemic: preparing for re-entry

Purpose

During the COVID-19 pandemic, most breast surgery for benign and malignant conditions has been postponed, creating a backlog of patients who will need surgery. A fair and transparent system for assessing the risk of further delaying surgery for individual patients to prioritize surgical scheduling is needed.

Methods

Factors related to risk of delaying surgery for breast patients were identified. Scores were assigned to each factor, with higher scores indicating a greater risk from delaying surgery. REDCap and Microsoft Excel tools were designed to track and score delayed patients.

Results

Published data and multidisciplinary clinical judgement were used to assign risk scores based on patient and tumor factors, length of delay, and tumor response to preoperative therapy. Patients completing neoadjuvant chemotherapy were assigned the highest scores as their options for delaying surgery are most limited. Among patients receiving neoadjuvant endocrine therapy or no medical therapy, higher scores were assigned for low-estrogen receptor or high-genomic risk scores, higher grade, larger tumors, younger age and longer delay. High priority scores were assigned for progression during preoperative therapy. Low scores were assigned for re-excisions, atypical lesions and other benign indications. There was good agreement of the tool’s ranking of sample patients with rankings by experienced clinicians. The tool generates risk-stratified patient lists by surgeon or institution to facilitate assignment of surgery dates.

Conclusions

This tool generates a clinically consistent, risk-stratified priority list of breast surgical procedures delayed by the COVID-19 pandemic. This systematic approach may facilitate surgical scheduling as conditions normalize.

Neoadjuvant endocrine therapy in locally advanced estrogen or progesterone receptor-positive breast cancer: determining the optimal endocrine agent and treatment duration in postmenopausal women-a literature review and proposed guidelines

Introduction

For patients with locally advanced estrogen receptor or progesterone receptor-positive breast cancer, neoadjuvant endocrine therapy (NET) facilitates down-staging of the tumor and increased rates of breast-conserving surgery. However, NET remains under-utilized, and there are very limited clinical guidelines governing which therapeutic agent to use, or the optimal duration of treatment in postmenopausal women. This literature review aims to discuss the evidence surrounding (1) biomarkers for patient selection for NET, (2) the optimal neoadjuvant endocrine agent for postmenopausal women with locally advanced breast cancer, and (3) the optimal duration of NET. In addition, we make initial recommendations towards developing a clinical guideline for the prescribing of NET.

Method

A wide-ranging search of online electronic databases was conducted using a truncated PIC search strategy to identify articles that were relevant to these aims and revealed a number of key findings.

Results

Randomized trials have consistently demonstrated that aromatase inhibitors are more effective than tamoxifen, in terms of objective response rate and rate of BCS, and should be used as first-line NET. The three available aromatase inhibitors have so far been demonstrated to be biologically equivalent, with the choice of aromatase inhibitor not having been shown to affect clinical outcomes. There is increasing evidence for extending the duration of NET beyond 3 to 4 months, to at least 6 months or until maximal clinical response is achieved. While on-treatment levels of the proliferation marker Ki67 are predictive of long-term outcome, the choice of adjuvant therapy in patients who have received NET and then surgery is best guided by the preoperative endocrine prognostic index, or PEPI, which incorporates Ki67 with other clinical parameters.

Conclusion

This study reveals that in appropriately selected patients, NET can provide equivalent clinical benefit to neoadjuvant chemotherapy in the same cohort, if suitable treatments and durations are chosen. Our findings highlight the need for better defined biomarkers both for guiding patient selection and for measuring outcomes. Development of standard guidelines for the prescribing of NET has the potential to improve both clinical outcomes and quality of life in this patient cohort.

Neoadjuvant Model as a Platform for Research in Breast Cancer and Novel Targets under Development in this Field

For decades, the neoadjuvant setting has provided a useful scenario for research in breast cancer. Historically, neoadjuvant clinical trials, either hormone therapy-based or chemotherapy-based, have tried to recapitulate the results of their counterpart adjuvant studies, but with smaller patient numbers, more rapid outcomes (clinical response and/or pathologic complete response (pCR)), together with additional biologic information. As for neoadjuvant chemotherapy trials, the increase in pCR rates has been recently accepted as an appropriate surrogate marker to accelerate drug approval in high-risk breast cancer patients. In this setting, with the exception of luminal A tumors, pCR has been associated with improved long-term outcomes, particularly when the analysis is based on specific trials for each breast cancer subtype. For luminal tumors receiving neoadjuvant endocrine therapy, Ki67 at 2-4 weeks and the preoperative endocrine prognostic index score are the most accepted intermediate markers of efficacy, which will be validated in ongoing larger trials. In this review, we describe the different neoadjuvant designs: from the classical randomized trials in which treatment is delivered for 6 or more months to short non-therapeutic presurgical studies lasting just 2 or 3 weeks. We also review the main neoadjuvant trials, either ongoing or completed, for luminal, triple-negative, and HER2-positive breast cancer. The translational effort and research of biomarkers conducted in these studies will be particularly addressed.

Network Meta-Analysis of the Effectiveness of Neoadjuvant Endocrine Therapy for Postmenopausal, HR-Positive Breast Cancer

In clinical practice, it is necessary to define an optimal choice from many different therapeutic regimens. This study aimed to assess the efficacy and safety of neoadjuvant endocrine therapy (NET) for breast cancer patients. Randomized clinical trials were included. Nine studies comprising 2133 patients were included in the final analysis. Network meta-analysis showed that everolimus plus letrozole was more easily accepted by patients than exemestane (≥20wks) (odds ratio (OR): 856697.02, 95% confidence intervals (95%CI): 1.88 to 87242934...); exemestane (≥20wks) had worse acceptability than letrozole (OR: 0.00, 95%CI: 0.00 to 0.98). Letrozole produced a better clinical objective response (COR) than tamoxifen (OR: 1.99, 95%CI: 1.04 to 3.80). The incidence of fatigue between the anastrozole plus gefitinib group and the everolimus plus letrozole group was significantly different (OR: 0.08, 95%CI: 0.01 to 0.83). The exemestane (<20wks) plus celecoxib group had fewer hot flushes than others. Ranking showed the everolimus plus letrozole was most likely rank first in comparisons of COR and acceptability, and had a 64% possibility to rank first after stochastic multi-criteria acceptability analysis. In conclusion, our study showed that letrozole plus everolimus is the most effective treatment for postmenopausal, hormone receptor-positive breast cancer in the neoadjuvant setting.

Primary Hormone Therapy in Elderly Women with Hormone-Sensitive Locoregional Breast Cancer: Endocrine Therapy Alone Is a Reasonable Alternative in Selected Patients

BACKGROUND

Treatment with aromatase inhibitors (AIs) followed by surgery is often recommended for women with locoregional hormone-sensitive breast cancer. However, no study has compared the efficacy of AIs alone versus AIs followed by surgery.

METHODS

33 postmenopausal breast cancer patients were treated with primary hormone therapy. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor type 2 receptor (HER2) expression levels were analyzed by immunohistochemistry. After hormone therapy, eligible patients underwent surgery, and those who were not candidates for surgery continued on hormone therapy. We retrospectively analyzed time to progression, overall survival, response, and impact of surgery on outcome.

RESULTS

All patients were ER+. HER2 was successfully analyzed in 30 patients, all of whom were HER2-. The median time to progression was 94 months, and the median overall survival was not reached, while the mean overall survival was 123 months. The overall response rate was 63.6%, with 9.1% complete responses. No significant differences in time to progression or survival were observed between patients who underwent surgery and those who did not.

CONCLUSIONS

Primary hormone therapy with AIs is effective in elderly breast cancer patients with high levels of hormone receptors and may provide a feasible and tolerable alternative to surgery in selected hormone-sensitive breast cancer patients.

Pegylated liposomal doxorubicin plus cyclophosphamide followed by paclitaxel as primary chemotherapy in elderly or cardiotoxicity-prone patients with high-risk breast cancer: results of the phase II CAPRICE study

Anthracycline and taxane-based primary chemotherapy (PCT) is the standard treatment for high-risk breast cancer (HRBC). However, conventional anthracyclines are not commonly used in elderly patients or those prone to cardiotoxicity. Pegylated liposomal doxorubicin, (PLD) has comparable efficacy, but less cardiotoxicity than conventional anthracyclines. We conducted a phase II single-arm trial to assess the efficacy and safety of PCT based on PLD followed by paclitaxel (PTX) in a HRBC population usually undertreated. Fifty patients with stage II-IIIB breast cancer and at least one risk factor for developing cardiotoxicity initiated PLD 35 mg/m(2) plus cyclophosphamide 600 mg/m(2) every 4 weeks for four cycles, followed by 80 mg/m(2) weekly PTX for 12. Close cardiac monitoring was performed. Primary endpoint was the pathological complete response rate (pCR) in the breast. Treatment delivery and toxicities were assessed. Eighty-four per cent of patients were older than 65 years, 64 % suffered from hypertension, and 10 % had prior cardiac disease. In an intention-to-treat analysis, breast pCR was 32 % (95 % CI 19.5-46.7 %) and pCR in breast and axilla was 24 % (95 % CI 12.1-35.8 %). At diagnosis only, 26 % of patients were candidates for breast conservative surgery, which increased to 58.7 % after PCT. No significant decrease in left ventricular ejection fraction was seen. PLD followed by PTX was feasible in a fragile population of patients who were not candidates for conventional doxorubicin. Moreover, it achieved a pCR similar to standard therapy and could therefore be an option for elderly patients or cardiotoxicity-prone who present HRBC.

One-Year Neoadjuvant Endocrine Therapy in Breast Cancer

The evaluation of the effects of 1-year endocrine therapy (NET) was aimed at. A retrospective analysis of 42 cases with 46 stage II-III invasive, hormone receptor-positive, HER2-negative breast cancers was performed. One-year NET was planned with letrozole (n = 33, postmenopausal group), or with goserelin plus letrozole (n = 7) or with goserelin plus tamoxifen (n = 2) (premenopausal group). Surgery was performed in accordance with the initial stage and the response to therapy. With regard to the tumor remaining in the surgical specimen, risk groups were constructed: Group 1: stage 0, pathological complete regression (pCR); Group 2: stages IA-IIA; Group 3: stages ≥ IIB + cases with clinical progression. Due to local progression, NET was replaced by neoadjuvant chemotherapy in three patients (four tumors). In two postmenopausal patients, letrozole was replaced by tamoxifen because of the insufficient treatment effect. In 19/42 cases, breast-conserving surgery was performed. Within Group 1, there was no cancer in four cases, while only DCIS remained in 2 (pCR: 13 %); Groups 2 and 3 comprised 25 and 15 cases, respectively. The likeliness of a good response (Groups 1 and 2 vs. Group 3) to NET was increased by 7 % for every 1 % increase of the expression of ER (OR = 1.070; 95 % CI: 1.007-1.138, p = 0.029). Progression-free survival differed according to treatment response (p = 0.001). The post-therapy Ki67 value of ≤ 15 % had only a marginal effect on survival. No other associations were detected between the tumor characteristics and the therapeutic response or survival. Long-duration NET is effective and safe in cases of hormone-sensitive breast cancer.

Invasive lobular breast cancer and its variants: how special are they for systemic therapy decisions?

The WHO classification of breast tumors distinguishes, besides invasive breast cancer 'of no special type' (former invasive ductal carcinoma, representing 60-70% of all breast cancers), 30 special types, of which invasive lobular carcinoma (ILC) is the most common (5-15%). We review the literature on (i) the specificity and heterogeneity of ILC biology as documented by various analytical techniques, including the results of molecular testing for risk of recurrence; (ii) the impact of lobular histology on prediction of prognosis and effect of systemic therapies in patients. Though it is generally admitted that ILC has a better prognosis than IDC, is endocrine responsive, and responds poorly to chemotherapy, currently available data do not unanimously support these assumptions. This review demonstrates some lack of specific data and a need for improving clinical research design to allow oncologists to make informed systemic therapy decisions in patients with ILC. Importantly, future studies should compare various endpoints in ILC breast cancer patients among the group of hormonosensitive breast cancer.

Long-term outcome of neoadjuvant endocrine therapy with aromatase inhibitors in elderly women with hormone receptor-positive breast cancer

Background

Aromatase inhibitors (AIs) are more effective than tamoxifen as neoadjuvant endocrine therapy (NET) for hormone receptor (HR)-positive breast cancer. Here we report the surgical and long-term outcome of elderly postmenopausal patients with locally advanced, HR-positive breast cancer treated with preoperative AIs.

Methods

Between January 2003 and December 2012, 144 postmenopausal patients inoperable with breast conservative surgery (BCS) received letrozole, anastrozole, or exemestane as NET. Patients underwent breast surgery and received adjuvant AIs. Adjuvant systemic therapy, chemotherapy and/or trastuzumab, and adjuvant radiotherapy were administered as appropriate, but limited to high-risk patients with few or no comorbidities.

Results

After a median follow-up of 49 months, 4 (3.0 %) patients had local relapse, 18 (12.5 %) had distant metastases, and 24 (17.0 %) died. BCS was performed in 121 (84.0 %) patients. A tumor size <3 cm and human epidermal growth factor receptor 2 (HER2) negativity were predictors of BCS. The achievement of BCS and grade G1 were significantly associated with longer disease-free survival (DFS) (p = 0.009 and p = 0.01, respectively) and overall survival (p = 0.002 and p = 0.005, respectively). Residual tumor ≤2 cm (yT0–yT1) in the longest diameter after NET was also statistically associated with longer DFS (p = 0.005).

Conclusions

The results of this retrospective study indicate that elderly breast cancer patients with a tumor size <3 cm at diagnosis and HER2 negativity have a higher probability of achieving BCS after NET. Moreover, patients treated with BCS and with grade G1 tumor have a reduced risk of recurrence and death in the long-term follow-up.

Aromatase inhibitors in the breast cancer clinic: focus on exemestane

Breast cancer is the most prevalent type of cancer in women and responsible for significant female cancer-related mortality worldwide. In the Western world, over 80% of breast cancers are hormone-receptor positive for which endocrine therapy is administered. The main anti-estrogen treatments in use consist of selective estrogen-receptor modulators, such as tamoxifen, and third-generation aromatase inhibitors (AIs), such as exemestane, letrozole, and anastrozole. In this review, the focus will lie on exemestane, its clinical use, and its side-effect profile. Exemestane is the only third-generation steroidal AI. Its efficacy as a first-line treatment in metastatic breast cancer has been demonstrated. Therefore, exemestane could be considered a valid first-line therapeutic option, but it also can be used in second-line or further situations. Exemestane is mostly used as part of sequential adjuvant treatment following tamoxifen, but in this setting it is also active in monotherapy. Furthermore, this AI has been studied in the neoadjuvant setting as presurgical treatment, and even as chemoprevention in high-risk healthy postmenopausal women. It may reverse side effects of tamoxifen, such as endometrial changes and thromboembolic disease but may also cause some inconvenient side effects itself. Additionally, there is a lack of total cross-resistance between exemestane and nonsteroidal AIs as far as their anti-tumoral efficacy is concerned; moreover the two classes of AIs display a nontotal overlapping toxicity profile. Taking together, exemestane can be considered as a useful treatment option at all stages of breast cancer.

Neoadjuvant endocrine treatment for breast cancer: from bedside to bench and back again?

In recent years, considerable attention has been paid to the role of neoadjuvant chemotherapy as a pluripotential test bed for the treatment of breast cancer. Although traditionally reserved to render inoperable disease operable, neoadjuvant chemotherapy is increasingly being used to improve the chance for breast-conserving surgery, to gain information on pathologic response rates for a more rapid assessment of new chemotherapy-biologic regimens, and also to study in vivo tumour sensitivity or resistance to the agent being used. Similarly, use of neoadjuvant endocrine treatment was also traditionally restricted to elderly or frail patients who were felt to be unsuitable for chemotherapy. It is therefore not surprising that, given the increasing realization of the pivotal role of endocrine therapy in patient care, there is enhanced interest in neoadjuvant endocrine therapy not only as a less-toxic alternative to chemotherapy, but also to assess tumour sensitivity or resistance to endocrine agents. The availability of newer endocrine manipulations and increasing evidence that the benefits of chemotherapy are frequently marginal in many hormone-positive patients is making endocrine therapy increasingly important in the clinical setting. The hope is that, one day, instead of preoperative endocrine therapy being restricted to the infirm and the elderly, it will be used in the time between biopsy diagnosis and surgery to predict which patients will or will not benefit from chemotherapy in the adjuvant setting.

Presurgical (neoadjuvant) endocrine therapy is a useful model to predict response and outcome to endocrine treatment in breast cancer patients

Endocrine therapy of breast cancer has been improved continuously during the last decades. Currently, aromatase inhibitors are dominating treatment algorithms for postmenopausal women with hormone-receptor positive breast cancer while tamoxifen still is the most widely used drug for premenopausal women. Several research tools and study designs have been used to challenge established drugs and develop the field of antihormonal therapy. One pivotal study option has been the observation of clinical responses during presurgical/neoadjuvant endocrine therapy (PSET/NET). This strategy has several major advantages. First, the breast tumor, still present in the patient's breast during therapy, can be followed by clinical observations and radiological measurements and any treatment effect will be immediately registered. Second, tumor biopsies may be obtained before initiation and following therapy allowing intra-patient comparisons. These tumor-biopsies may be used for the evaluation of intra-tumor changes associated with drug treatment. As examples, presurgical breast cancer trials have been used to evaluate intra-tumor estrogen levels during therapy with aromatase inhibitors and also to study mechanisms involved in the adaptation processes to estrogen suppression. Biomarker studies have provided information that may be used for patient selection in the future. Finally, recently published results from presurgical trials testing combinations of classical endocrine drugs and novel targeted therapies have produced promising results.

Hormonal and antimicrobial therapy in theriogenology practice: currently approved drugs in the USA and possible future directions

Hormonal and antimicrobial therapies are essential to regulate and maintain healthy reproduction in domestic animals. The appropriate and legal use of these compounds is ultimately the responsibility of the veterinarian and other users, with a primary mission to directly protect and promote the health of animals, and indirectly the health of people. The appropriate use of these products is defined by the Federal Food, Drug, and Cosmetic Act, 21 United States of America § 301 et seq and implementing regulations in the Code of Federal Regulations. In the past, use of a drug in an animal for an unapproved use violated this Act. However, passage of the Animal Medicinal Drug Use Clarification Act 1994 legalized the extra-label use of certain animal and human drugs in veterinary practice for treating diseases. This manuscript reviews currently approved hormonal and antimicrobial drugs for use in theriogenology. Considering the ever increasing knowledge in the area of veterinary reproduction, particularly in the treatment and control of reproduction using antimicrobials and hormones, it would be beneficial to widen the therapeutic options in these categories. The potential for widening the therapeutic options is also discussed in this review, by providing a non-exhaustive but essential list of potential new drugs for use in clinical animal reproduction (theriogenology).

Ki67 index changes, pathological response and clinical benefits in primary breast cancer patients treated with 24 weeks of aromatase inhibition

Aromatase inhibitor shows efficacy for hormone receptor positive postmenopausal breast cancer. We evaluated the activity of 24 weeks of aromatase inhibition with exemestane for primary breast cancer in a neoadjuvant setting. Patients with stage II/IIIA invasive breast cancer with estrogen receptor (ER) and/or progesterone receptor (PgR)-positive status were eligible. Primary endpoints were objective response rate (ORR) and safety. A steroidal aromatase inhibitor exemestane of 25 mg/day was administered for 16 weeks with an 8-week extension. Secondary endpoints were rates of breast-conserving surgery (BCS), and change of Ki67 index and ER/PgR expression in central laboratory analyses. Between March 2006 and December 2007, 116 patients were enrolled. Among those, 102 patients completed 24 weeks of administration. The ORR was 47% (55/116) at Week 16 and 51% (59/116) at Week 24, respectively. No serious toxicity was seen. ORR was associated with ER Allred scores but not with PgR scores. The significant reduction in Ki67 index was confirmed. No progression was experienced in tumors with less than 15% Ki67 index. Pathological response was observed in 28 (30%) of 94 evaluated cases. No statistical correlation between pre-treatment Ki67 index and pathological response was detected; however, a trend of correlation was found between the post-treatment preoperative endocrine prognostic index (PEPI), a prognostic score and the pathological response. At diagnosis, 59 patients (51%) would have required mastectomy but 40 patients were converted to BCS, showing an increase in the rate of BCS (77%). The 24-week aromatase inhibition provided preferable clinical benefits with significant reduction in Ki67 index. More precise mechanisms of the response need to be investigated.

Predictors of response to exemestane as primary endocrine therapy in estrogen receptor-positive breast cancer

Endocrine therapy is the most important treatment of choice for estrogen receptor (ER)-positive breast cancer. Potential mechanisms for resistance to endocrine therapy involve ER-coregulatory proteins and cross-talk between ER and other growth factor-signaling networks. However, the factors and pathways responsible for endocrine therapy resistance, particularly resistance to aromatase inhibitors, have not been clearly established. Sixteen postmenopausal patients with ERalpha-positive primary breast cancer were treated daily with 25 mg of exemestane (an aromatase inhibitor) for 6 months. Expressions of ERalpha, ERbeta, progesterone receptor (PgR), androgen receptor (AR), amplified in breast cancer 1 (AIB1), aromatase, epidermal growth factor receptor, human epidermal growth factor receptor type 2, Ki67, cyclin D1, p53, Bcl2, signal transducer and activator of transcription 5 (Stat5), and insulin-like growth factor binding protein 5 (IGFBP5), and phosphorylations of ERalpha serine (Ser) 118, ERalpha Ser167, Akt Ser473, and p44/42 MAPK threonine (Thr) 202/tyrosine (Tyr) 204, were examined by immunohistochemistry on pretreatment tumor biopsies and post-treatment surgical specimens. Analyses were made to test for correlations with response to exemestane. Of the 16 patients, seven responded and nine retained stable disease. High-level expression of AIB1 and phosphorylation of Akt Ser473 were significantly associated with a better response to exemestane, suggesting that these factors could be considered as predictors of exemestane response. Expressions of ERalpha, ERbeta, PgR, aromatase, Ki67, cyclin D1, and p53, and phosphorylations of ERalpha Ser118, ERalpha Ser167, and p44/42 MAPK Thr202/Tyr204, were decreased, whereas expressions of Stat5 and IGFBP5 were increased in post-treatment specimens compared to the values in pretreatment biopsies. Thus, the analysis of factors involved in the estrogen-dependent growth-signaling pathways may be useful in identifying patients responsive to exemestane.

Neoadjuvant endocrine treatment in primary breast cancer - review of literature

Chemotherapeutic agents have dominated neoadjuvant treatment compared to endocrine agents in the past and have demonstrated their ability to produce tumour shrinkage to allow breast conservation. However, in the more recent setting, studies have been emerging with the use of aromatase inhibitors, especially comparing its use with tamoxifen in selected group of patients. The role of tamoxifen in its ability to achieve tumour shrinkage has been evaluated in the past, and has shown to produce slow but sustained response. Aromatase inhibitors have shown superiority over tamoxifen in adjuvant and metastatic setting, and the aim of our study was to compare their outcome with regard to response and breast conservation in the neoadjuvant setting. We also looked into optimum duration of neoadjuvant treatment and also the role of pathological complete response as a surrogate marker for clinical outcome. Our review highlights the superiority of aromatase inhibitors over tamoxifen in the neoadjuvant setting and even challenges chemotherapy with regard to response in selected group of patients.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.