Metastatic breast cancer: sequencing hormonal therapy and positioning of fulvestrant

Efficacy of fulvestrant in the treatment of postmenopausal women with endocrine-resistant advanced breast cancer in routine clinical practice

INTRODUCTION

This study aimed to describe the efficacy of fulvestrant 500 mg in postmenopausal women with estrogen receptor (ER)-positive advanced/metastatic breast cancer who had disease progression after receiving anti-estrogen therapy in clinical practice, getting real-world data.

MATERIALS AND METHODS

Multicenter, retrospective, observational study conducted in Spain. Postmenopausal women with locally advanced/metastatic ER-positive breast cancer who received treatment with fulvestrant 500 mg after progression with a previous anti-estrogen therapy were eligible. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), clinical benefit rate (CBR), duration of clinical benefit (DoCB), and safety profile.

RESULTS

A total of 263 women were evaluated (median age, 65.8 years). At a median follow-up of 21.5 months, median PFS and OS were 10.6 and 43.2 months, respectively. PFS according to 1st, 2nd, 3rd, and ≥ 4th lines were 11.5, 10.6, 9.9, and 8.5 months, respectively (p = 0.0245). PFS in patients with visceral involvement was 10 months vs 10.6 months in patients without visceral involvement (p = 0.6604), 9.6 months in patients with high Ki67 vs 10 months in patients with low Ki67 (p = 0.7224), and 10.2 months in HER2+ patients vs 10.3 months in HER2- patients (p = 0.6809). The CBR was 56.5% and the DoCB was 18.4 months. The most frequently adverse events were injection site pain (10.3%) and musculoskeletal disorders (7.6%).

CONCLUSIONS

Fulvestrant 500 mg administered in clinical practice was shown to be effective (PFS, 10.6 months; CBR, 56.5%) and well tolerated, in accordance with previous trials.

The first decade of estrogen receptor cistromics in breast cancer

The advent of genome-wide transcription factor profiling has revolutionized the field of breast cancer research. Estrogen receptor α (ERα), the major drug target in hormone receptor-positive breast cancer, has been known as a key transcriptional regulator in tumor progression for over 30 years. Even though this function of ERα is heavily exploited and widely accepted as an Achilles heel for hormonal breast cancer, only since the last decade we have been able to understand how this transcription factor is functioning on a genome-wide scale. Initial ChIP-on-chip (chromatin immunoprecipitation coupled with tiling array) analyses have taught us that ERα is an enhancer-associated factor binding to many thousands of sites throughout the human genome and revealed the identity of a number of directly interacting transcription factors that are essential for ERα action. More recently, with the development of massive parallel sequencing technologies and refinements thereof in sample processing, a genome-wide interrogation of ERα has become feasible and affordable with unprecedented data quality and richness. These studies have revealed numerous additional biological insights into ERα behavior in cell lines and especially in clinical specimens. Therefore, what have we actually learned during this first decade of cistromics in breast cancer and where may future developments in the field take us?

Tamoxifen resistance: from bench to bedside

Although tamoxifen is a classical example of a targeted drug, a substantial proportion of estrogen receptor alpha positive breast cancer patients does not benefit from the drug. Over the last few decades, many potential biomarkers have been discovered in cell biological studies that may aid in the prediction of tamoxifen sensitivity and guide in treatment selection. Nonetheless, the transition of such a biomarker from the scientific community towards a diagnostic test that can be used in daily clinical practice has been far from ideal, and such markers seldom face clinical introduction. From a large number of potential predictive biomarkers as described in cell biological literature, the clinical (translational) scientist has to make a decision which of these biomarkers should be tested in clinical material to determine their clinical validity. This problem is not trivial, since patient samples with clinical follow-up are a valuable asset that should therefore be cherished. In this review, we will describe a number of 'cell biological biomarkers' for tamoxifen resistance and their possible clinical implications. This may guide the clinical scientist in choosing what potential biomarkers to test on tumour samples, which may catalyse the translation of scientific discoveries into daily clinical practice of breast cancer medicine.

Tumor-Specific Systemic Treatment in Advanced Breast Cancer - How Long does it Make Sense?

SUMMARY: Metastatic breast cancer (MBC) is a chronic and incurable disease which can be kept steady for a long time with continuous oncologic therapy. There are various treatment options. Disease-free as well as overall survival were prolonged in many pharmaceutical studies. The therapist focuses on these oncologic parameters as well as the patient's quality of life. One central point of the communication between doctor and patient is the prediction by the medical team of how long to continue oncologic therapy and when to start palliative medicine in terms of best palliative care. Treatment options currently available for MBC as well as the importance of this difficult communication between the involved parties are pointed out. The end of tumor-specific oncologic therapy does not necessarily mean the end of therapeutic measures for the individual patient.

Recurrent breast cancer: treatment strategies for maintaining and prolonging good quality of life

BACKGROUND

Recurrent breast cancer remains a challenge for interdisciplinary treatment even though new therapeutic options are available.

METHODS

The PubMed database was selectively searched for articles that appeared from 1999 to 2009 and contained the key words "breast cancer," "recurrence," "metastatic," "advanced," and "treatment". Further sources consulted for this review included the German S3 guideline, the treatment recommendations of the German AGO-Mamma group, the NCCN guidelines, and the Cochrane database.

RESULTS

Locoregional recurrences are treated with curative intent. Metastatic breast cancer must be treated on an individualized basis: The treatment should be continued as long as its benefits for the individual patient outweigh its adverse side effects. Endocrine treatment is indicated for all patients whose tumors are hormone-receptor positive or of unknown receptor status and who have enough time for a response to be seen. Chemotherapy should be given if the tumor is hormone-receptor negative, if a rapid response is urgently needed, or if endocrine treatment has failed to produce a response. Combination chemotherapy improves response rates and prolongs progression-free survival, yet it does not prolong overall survival in comparison to monochemotherapy. In HER2-positive patients, first-line treatment with trastuzumab and monochemotherapy prolongs overall survival. Other treatment options include angiogenesis inhibitors, various tyrosine kinases inhibitors, radiotherapy, bisphosphonates, surgical or other ablative treatment of metastases, or a combination of these approaches, applied either simultaneously or consecutively.

CONCLUSIONS

While locoregional recurrences of breast cancer should be treated with curative intent, breast cancer with distant metastases is currently not curable. It is treated with the intention of restoring and maintaining good quality of life and relieving symptoms due to the metastases, rather than prolonging survival.