Advances in the management of metastatic breast cancer: options beyond first-line chemotherapy

This article provides an overview of recent advances in chemotherapy that may be used for the treatment of patients with locally advanced or metastatic breast cancer (MBC). Key phase ii and iii trial data for eribulin mesylate, ixabepilone, and nab-paclitaxel, published since 2006, are discussed on the basis of recency, depth, and quality.Eribulin mesylate is the first monotherapy to significantly increase overall survival in patients with pretreated MBC, but nab-paclitaxel offers a novel and safer mode of delivery in comparison with standard taxanes. By contrast, the use of ixabepilone will be limited for now, until the associated neurotoxicity can be better managed. Alongside a brief overview of the other major chemotherapies currently in use, we have aimed to provide a Canadian context for how these novel agents may be integrated into clinical practice.     

Therapeutic oophorectomy in metastatic breast cancer

One hundred five patients undergoing therapeutic oophorectomy for metastatic breast cancer (n = 105) from 1975 to 1985 were reviewed. There were 54 responders (51%) to oophorectomy, with a median duration of response of 16 months (range, 3 to 129 months). Thirty of 42 (71%) estrogen receptor (ER)-positive patients responded to oophorectomy versus five of 24 (21%) ER-negative patients (P less than 0.001). Of the 39 patients with unknown ER status, 19 (49%) responded to oophorectomy. Osseous, soft tissue, and pulmonary metastases responded at similar rates. Of the 16 patients who had received adjuvant chemotherapy, there were five responders (31%) to oophorectomy. Second-line endocrine therapy was effective in 29 of 53 (55%) patients. Fifteen of 28 (54%) ER-positive patients responded to second-line endocrine therapy while two of six (33%) ER-negative patients responded. Twenty-three of 37 (62%) oophorectomy responders responded to second-line endocrine therapy versus six of 16 (38) nonresponders. Oophorectomy appears to be a valuable palliative treatment for metastatic breast cancer. ER-positive patients have the best chance of responding to this therapy. However, ER-negative patients have a reduced but definite chance of responding with a good duration of response. Response to further endocrine treatments is predicted by response to oophorectomy and to a lesser degree by ER status.     

Symptom management in metastatic breast cancer

Approximately 40,000 women die as a result of breast cancer each year and many more live with advanced disease. When breast cancer recurs, the goals of treatment often shift from one of cure to controlling the disease for as long as possible while palliating symptoms interfering with the patient's functional status and quality of life. This requires ongoing discussions with the patient and family about the goals of care. Many symptoms depend on the site of metastasis, with bone being the most frequent, and commonly occur with fatigue, depression, insomnia, and pain. The purpose of this paper is to identify and provide an overview of the management of the most common symptoms in patients with breast cancer metastases.     

Therapeutic advances in the management of metastatic colorectal cancer

Metastatic colorectal cancer has long been considered as a short-term, poor prognosis, chemoresistant disease. Until the early 1990s, the impact of systemic chemotherapy on patient outcome was debated. Recently, the emergence of new therapeutic modalities (5-FU modulations and associations with oxaliplatin and irinotecan) has led to a significant improvement in tumor response rates and patient survival. Thus, the indications of curative surgery of visceral metastases, frequently preceeded and followed by chemotherapy, systemic or intra-arterial or both, have become more frequent. In this paper we will review and comment on the results of the major clinical trials published in the past 5 years and propose some decision strategies regarding the main clinical situations met in daily practice.     

Therapeutic advances in the management of metastatic colorectal cancer

Metastatic colorectal cancer has long been considered as a short-term, poor prognosis, chemoresistant disease. Until the early 1990s, the impact of systemic chemotherapy on patient outcome was debated. Recently, the emergence of new therapeutic modalities (5-FU modulations and associations with oxaliplatin and irinotecan) has led to a significant improvement in tumor response rates and patient survival. Thus, the indications of curative surgery of visceral metastases, frequently preceded and followed by chemotherapy, systemic or intra-arterial or both, have become more frequent. In this paper we will review and comment on the results of the major clinical trials published in the past 5 years and propose some decision strategies regarding the main clinical situations met in daily practice.     

Therapeutic potential of PARP inhibitors for metastatic breast cancer

Increasing understanding of the cellular aberrations inherent to cancer cells has allowed the development of therapies to target biological pathways, an important step towards individualization of breast cancer therapy. The clinical development of poly(ADP-ribose) polymerase (PARP) inhibitors, with their novel and selective mechanism of action, are an example of this strategy. PARP plays a key role in DNA repair mechanisms, particularly the base excision repair pathway. Initially developed as inhibitors able to enhance the cytotoxicity of radiation and certain DNA-damaging agents, they have more recently been shown to have single-agent activity in certain tumors. Inhibition of PARP in a DNA repair-defective tumor can lead to gross genomic instability and cell death by exploiting the paradigm of synthetic lethality. Several studies have evaluated the role of PARP inhibitors for treatment of breast cancer, particularly in the context of BRCA-mutated and triple-negative breast cancers. In addition, inhibition of PARPs repair functions for chemotherapy-induced DNA lesions has been shown to potentiate the effect of some chemotherapy regimens. This article discusses the current understanding of PARP inhibition as a treatment for metastatic breast cancer, evidence from clinical trials and addresses its future implications.     

Therapeutic potential of PARP inhibitors for metastatic breast cancer

Increasing understanding of the cellular aberrations inherent to cancer cells has allowed the development of therapies to target biological pathways, an important step towards individualization of breast cancer therapy. The clinical development of poly(ADP-ribose) polymerase (PARP) inhibitors, with their novel and selective mechanism of action, are an example of this strategy. PARP plays a key role in DNA repair mechanisms, particularly the base excision repair pathway. Initially developed as inhibitors able to enhance the cytotoxicity of radiation and certain DNA-damaging agents, they have more recently been shown to have single-agent activity in certain tumors. Inhibition of PARP in a DNA repair-defective tumor can lead to gross genomic instability and cell death by exploiting the paradigm of synthetic lethality. Several studies have evaluated the role of PARP inhibitors for treatment of breast cancer, particularly in the context of BRCA-mutated and triple-negative breast cancers. In addition, inhibition of PARPs repair functions for chemotherapy-induced DNA lesions has been shown to potentiate the effect of some chemotherapy regimens. This article discusses the current understanding of PARP inhibition as a treatment for metastatic breast cancer, evidence from clinical trials and addresses its future implications.     

Therapeutic options for contralateral axillary lymph node metastasis in breast cancer

Contralateral axillary lymph node metastasis (CAM) in breast cancer is rare, and the reason is unclear. CAM may be found at the time of primary breast cancer diagnosis or following primary tumor treatment. CAM staging and treatment methods are controversial. Hence, we summarized the features of CAM patients and explored the therapeutic options. We report the case of an 82-year-old woman with right breast cancer accompanied by CAM. The records of breast cancer patients with CAM in PubMed (January 2000-May 2020) were also reviewed. After undergoing comprehensive treatments (neoadjuvant chemotherapy, surgery, radiotherapy, endocrine therapy, and targeted therapy), no signs of recurrence and metastasis were noted during the 25-month follow-up. Overall, 17 studies (36 patients) were selected for the review, of which 15 had synchronous CAM and 21 had metachronous CAM. Nineteen of 22 patients had histologic grade 3. Forty percent (12/30) had ≥4 positive lymph nodes. Among these 36 patients, 9 had triple-negative breast cancers, and 9 were human epidermal growth factor receptor 2 positive. Among the 30 patients staged, 6 (20%) were in stage I; 7 (23.33%), stage II; and 17 (56.67%), stage III. Two patients received systemic therapy, while one received an unknown treatment. The remaining 33 patients all received local treatment (surgery or radiotherapy). The survival time of synchronous and metachronous CAM patients was 12-72 months with the death rate of 1/7 and 12-144 months with that of 3/12, respectively. CAM may be a regional manifestation rather than a distant metastasis. Comprehensive treatment, including surgery and radiotherapy, may provide better control.     

Goals and objectives in the management of metastatic breast cancer

Patients with metastatic breast cancer consist of a heterogeneous group of patients whose prognoses and clinical courses can vary depending on host factors, such as comorbidity and age, and on tumor factors, such as hormone-receptor status, grade, and anatomical site of disease. Although the median survival time for patients with metastatic breast cancer is 2-4 years, subsets of patients with either indolent or limited metastatic disease may have prolonged survival times. Further, expectations of treatment, both in terms of efficacy and of toxicity, vary greatly based upon the specific treatment, patient characteristics, and tumor characteristics. Thus, the goals of treatment for patients with metastatic breast cancer are influenced by estimates of prognoses as well as a balance between physician and patient preferences regarding efficacy and toxicity considerations. Traditionally, objective measures of response and survival have been the targeted end points in clinical trial design and in physician selection of therapy for metastatic breast cancer. More recently, issues of quality of life have surfaced as important end points, especially from the perspective of the patient. The decision-making process in selecting the optimal treatment for patients with metastatic breast cancer is, therefore, a multidimensional process involving subjective as well as objective goals of treatment. Ultimately, the benefits of treatment must justify the risks and toxicities of the treatment, and the impact of treatment should be measured in relation to specified goals. Both physician and patient perspectives are important in establishing the objectives of treatment, and this process is optimally an interactive and ongoing process throughout the course of disease.     

Metastatic breast cancer: understanding current management options

PURPOSE/OBJECTIVES: To review the standard treatment options for metastatic breast cancer, present recently approved chemotherapeutic and hormonal approaches, and describe novel biologic therapies, particularly the use of monoclonal antibodies. DATA SOURCES: Published articles, abstracts, and conference proceedings. DATA SYNTHESIS: Standard treatment options available to women with metastatic breast cancer include surgery, radiation therapy, hormonal therapy, chemotherapy, and palliative approaches. New chemotherapeutic approaches for the management of metastatic breast cancer include the recently approved agents paclitaxel, docetaxel, and capecitabine. New hormonal agents such as toremifene, letrozole, and exemestane also have been approved. Finally, an agent from a new class of agents--biologic response modifiers (BRMs)--now. Is available. Trastuzumab, a monoclonal antibody (one class of BRMs), is a new and promising approach available to a subpopulation of women with metastatic breast cancer. CONCLUSION: Although standard treatment options for the management of metastatic breast cancer may prolong survival for some, they have not resulted in a cure for the majority of women. Recent advances in the understanding of cancer cellular biology have led to newer approaches such as monoclonal antibodies and other BRMs that may offer hope of extended survival and improved quality of life for certain women. This field is growing quickly, and new targets for breast cancer therapy are being studied. IMPLICATIONS FOR NURSING PRACTICE: Nurses who become familiar with newer treatment options available for the management of metastatic breast cancer, including new chemotherapeutic and hormonal approaches and monoclonal antibody therapy, are better able to provide information and support for their patients. Clinicians must understand the criteria for patient selection for newer agents, particularly trastuzumab. In addition, recognizing adverse effects and knowing the management strategies for treatment-related toxicities help to ensure positive patient outcomes.     

Landmark trials in the medical oncology management of metastatic breast cancer

Significant advances in the management of metastatic breast cancer (MBC) have guided more personalized treatment according to disease biology and led to improved survival outcomes and quality of life for patients. In this review, we discuss landmark clinical trials in medical oncology that have shaped the current standard of care for MBC. Combinations of endocrine therapy with cyclin-dependent kinase 4/6 inhibitors have led to substantial improvements in overall survival, thus becoming standard first-line treatment for patients with HR-positive MBC. Inhibition of the PI3K and mTOR pathway is another promising strategy to overcome resistance to endocrine therapy. HER2-targeted therapies have also evolved with the addition of pertuzumab to trastuzumab plus a taxane demonstrating remarkable overall survival advantage in patient with HER2-positive MBC. In second or later line therapies, novel anti-HER2 antibody-drug conjugates and TKIs have durable antitumor activity, survival benefit, and encouraging efficacy in the subgroup of patients with brain metastases. Triple negative breast cancer remains the most challenging subtype due to lack of druggable targets. Immunotherapy for patients with PDL-1 expression on tumor infiltrating immune cells and poly (ADP-ribose) polymerase inhibitors for those with germline BRCA1/2 mutations are the latest approved targeted strategies in this population. Numerous obstacles still exist in treating MBC, especially for patients whose disease develops resistance to available agents. Future research is eagerly awaited to address the optimal sequence or combination of therapies and to identify better biomarkers to guide precision medicine.     

Triple-negative breast cancer: current management and future options

Triple-negative breast cancer is a particularly difficult to treat and biologically aggressive disease with limited treatment options. However, a subset of patients with triple-negative tumours may respond to chemotherapy. Therefore, optimisation of chemotherapy regimens may be key in treating triple-negative breast cancer. Emerging treatment approaches include novel chemotherapeutic agents such as the epothilones. The epothilones are a group of novel microtubule-stabilising agents with demonstrated activity in anthracycline-/taxane-resistant triple-negative breast cancer, and ongoing trials are evaluating the combination of epothilones with targeted agents or inclusion of epothilones in novel combination regimens. Other interesting new treatment options include the PARP inhibitors, which are currently in clinical trials for triple-negative breast cancer.     

Therapeutic vaccination against fibronectin ED-A attenuates progression of metastatic breast cancer

Therapeutic vaccination targeting self-molecules is an attractive alternative to monoclonal antibody-based therapies for cancer and various inflammatory diseases. However, development of cancer vaccines targeting self-molecules has proven difficult. One complicating factor is that tumor cells have developed strategies to escape recognition by the immune system. Antigens specifically expressed by the tumor vasculature can therefore provide alternative targets. The alternatively spliced extra domain-A and B (ED-A and ED-B) of fibronectin are expressed during vasculogenesis in the embryo, but essentially undetectable under normal conditions in the adult. However, these domains are re-expressed during tumor angiogenesis and matrix remodeling, which renders them highly interesting for targeted cancer therapies.Using the MMTV-PyMT transgenic model of metastatic mammary carcinoma, we show that tumor burden can be significantly decreased by immunization against ED-A in a therapeutic setting. Furthermore, we found that in mice carrying anti-ED-A antibodies the number of metastases was reduced. ED-A immunization increased infiltration of macrophages and compromised tumor blood vessel function. These findings implicate an attack of the tumor vasculature by the immune system, through a polyclonal antibody response. We conclude that tumor vascular antigens are promising candidates for development of therapeutic vaccines targeting growth of primary tumors as well as disseminated disease.     

Use and abuse of taxanes in the management of metastatic breast cancer

Taxanes are currently introduced early in the treatment of patients with metastatic breast cancer (MBC), both as single agents and in combination with anthracyclines. Two different patient populations exist: those with no or minimal prior anthracycline exposure and those who have failed previous anthracyclines. The data generated through phase III trials in first-line MBC therapy will be reviewed and their interpretation for routine clinical practice (use versus abuse) will be discussed. Ways of improving taxane-based treatment tailoring both in the pre- and postgenomic eras will be addressed.     

Gemcitabine in the management of metastatic breast cancer: a systematic review

Background

A systematic review of the evidence for gemcitabine chemotherapy, alone or in combination, in women with metastatic/advanced breast cancer was undertaken in order to determine gemcitabine’s role in the first-line and/or second-line or greater setting.

Methods

MEDLINE, EMBASE, the American Society of Clinical Oncologists, San Antonio Breast Cancer Symposium proceedings, and the Cochrane Library were searched through September 2006 for randomized controlled trials and non-randomized phase two trials.

Results

Eighty-three trials were identified, including four randomized phase III trials. All of the phase III trials included first-line patients. Two of the phase III trails demonstrated clinical benefit with gemcitabine-based chemotherapy in terms of superior efficacy or less toxicity while two phase III trials found no clinical benefit based on less efficacy or increased toxicity. Although 78 phase II trials of gemcitabine alone or in combination with other chemotherapy agents were identified, few combinations showed results compelling enough to warrant randomized trials.

Conclusion

Available data do not support the acceptance of gemcitabine as a standard therapeutic option in women with metastatic breast cancer in the third-line or greater setting, nor should it be considered as first-line therapy in anthracycline naïve women. Gemcitabine appears to be most effective when administered with a taxane (docetaxel/paclitaxel) in the first- or second-line setting, with gemcitabine/taxane combinations representing a viable alternative to currently accepted taxane combinations such as capecitabine/docetaxel. There is no evidence at this time to support the use of gemcitabine triplets, given the equal efficacy to anthracycline triplets and the added toxicity.

     

Diagnosis and surgical management of breast cancer metastatic to the spine

Breast cancer is the most common malignancy and the second leading cause of death in Western women. Breast cancer most commonly metastasizes to the bone and has a particular affinity with the spine, accounting for 2/3 of osseous metastases discovered. With significant improvements in cancer therapies, the number of patients at risk for symptomatic spinal metastases is likely to increase. Patients may suffer from intractable pain and neurological dysfunction, negatively influencing their quality of life. Timely diagnosis of patients is crucial and has been aided by several breakthrough advances in imaging techniques which aid in detection, staging, and follow-up of bone metastases. Breast metastases are usually responsive to hormonal therapy and pharmacologic interventions, but skeletal metastases often require surgical intervention. The treatments are palliative but goals include the preserving or restoring neurologic function, ensuring spinal stability, and relieving pain. Advances in surgical techniques and instrumentation have allowed more effective decompression and stabilization of the spine, and with the support of recent evidence the trend has shifted towards using more advanced surgical options in appropriately selected patients. In this review, the clinical presentation, diagnosis, patient selection, and surgical management of breast cancer metastatic to the spine are discussed.