Optimizing the treatment of metastatic breast cancer

Characterizing unique supportive care needs among women living with metastatic breast cancer: A qualitative study

Background

Women with metastatic breast cancer face unique challenges as they cope with life-limiting prognoses and arduous treatments. However, the vast majority of research has focused on optimizing quality of life in women with early-stage, non-metastatic breast cancer and little is known about supportive care needs among women living with metastatic cancer. As part of a larger project that sought to inform the development of a psychosocial intervention, the aim of this study was to characterize supportive care needs among women with metastatic breast cancer and elucidate challenges unique to living with a life-limiting prognosis.

Methods

Four, two-hour focus groups with 22 women were audio-recorded, transcribed verbatim, and analyzed in Dedoose using a general inductive approach to code categories and extract themes.

Results

A total of 16 codes emerged from 201 participant comments regarding supportive care needs. Codes were collapsed into four supportive care need domains: 1. psychosocial, 2. physical and functional, 3. health system and information, and 4. sexuality and fertility needs. The most prevalent needs were breast cancer-related symptom burden (17.4%), lack of social support (14.9%), uncertainty (10.0%), stress management (9.0%), patient-centered care (7.5%), and sexual functioning (7.5%). More than half of needs (56.2%) were in the psychosocial domain and more than two-thirds of needs (76.8%) were in the psychosocial and physical and functional domains. Supportive care needs unique to living with metastatic breast cancer included the cumulative effects of continuously undergoing cancer treatment on symptom burden, worry from scan-to-scan regarding response to cancer treatments, diagnosis-related stigma and social isolation, end-of-life concerns, and misconceptions regarding metastatic breast cancer.

Conclusions

Findings suggest that women with metastatic breast cancer have unique supportive care needs compared to women with early-stage breast cancer that are specific to living with a life-limiting prognosis and are not typically captured in existing self-report measures of supportive care needs. Results also highlight the importance of addressing psychosocial concerns and breast cancer-related symptoms. Women with metastatic breast cancer may benefit from early access to evidence-based interventions and resources that specifically address their supportive care needs and optimize quality of life and wellbeing.

In vitro study to assess the efficacy of CDK4/6 inhibitor Palbociclib (PD-0332991) for treating canine mammary tumours

Therapy of canine mammary tumours (CMTs) with classical antitumour drugs is problematic, so better therapeutic options are needed. Palbociclib (PD-0332991) is an innovative and effective anticancer drug for the treatment of breast cancer in women. Palbociclib is an inhibitor of cyclin-dependent kinase 4 (CDK4) and CDK6, which are key regulators of the cell cycle machinery and thus cell proliferation. In the present in vitro study, we investigated whether Palbociclib also represents a candidate drug to combat CMT. For this purpose, the effect of Palbociclib was analysed in P114 and CF41 cells, two CMT cell lines with an endogenous CDK4/6 co-expression. Incubation of P114 and CF41 cells with Palbociclib resulted in a dose- and time-dependent loss of phosphorylated retinoblastoma protein (pRb), a classical CDK4/6 substrate within the cell cycle machinery. Moreover, treatment of CMT cells with Palbociclib-induced cell cycle arrest affected cell viability, prevented colony formation and impaired cell migration activity. Palbociclib also inhibited the growth of P114 and CF41 cell spheroids. Immunohistochemical analysis of canine patient samples revealed a consistent expression of CDK6 in different canine mammary carcinoma types, but an individual and tumour-specific expression pattern of phosphorylated pRb independent of the tumour grade. Together, our findings let us suggest that Palbociclib has antitumour effects on CMT cells and that canine patients may represent potential candidates for treatment with this CDK4/6 inhibitor.

LAPTM4B gene copy number gain is associated with inferior response to anthracycline-based chemotherapy in hormone receptor negative breast carcinomas

PURPOSE

To determine the associations between lysosomal-associated transmembrane protein 4b (LAPTM4B) gene copy number and response to different chemotherapy regimens in hormone receptor negative (HR-) primary breast carcinomas.

PATIENTS AND METHODS

Two cohorts were analyzed: (1) 69 core biopsies from HR-breast carcinomas treated with neoadjuvant chemotherapy (anthracycline based in 72.5% of patients and non-anthracycline based in 27.5% of patients). (2) Tissue microarray (TMA) of 74 HR-breast carcinomas treated with adjuvant therapy (77.0% of the patients received anthracycline, 17.6% of the patients non-anthracycline-based therapy, and in 5.4% of the cases, no treatment data are available). Interphase FISH technique was applied on pretreatment core biopsies (cohort I) and on TMAs (cohort II) using custom-made dual-labelled FISH probes (LAPTM4B/CEN8q FISH probe Abnova Corp.).

RESULTS

In the neoadjuvant cohort in the anthracycline-treated group, we observed a significant difference (p = 0.029) of average LAPTM4B copy number between the non-responder and pathological complete responder groups (4.1 ± 1.1 vs. 2.6 ± 0.1). In the adjuvant setting, the anthracycline-treated group of metastatic breast carcinomas was characterized by higher LAPTM4B copy number comparing to the non-metastatic ones (p = 0.046). In contrast, in the non-anthracycline-treated group of patients, we did not find any LAPTM4B gene copy number differences between responder vs. non-responder groups or between metastatic vs. non-metastatic groups.

CONCLUSION

Our results confirm the possible role of the LAPTM4B gene in anthracycline resistance in HR- breast cancer. Analyzing LAPTM4B copy number pattern may support future treatment decision.

Epirubicin-Vinorelbine Intravenous Combination Followed by Oral Vinorelbine as First-Line Treatment in Metastatic Breast Cancer

Epirubicin and vinorelbine are considered active drugs in metastatic breast cancer. The optimal duration of a chemotherapy regimen for metastatic breast cancer patients is still unknown. Nevertheless, epirubicin has a dose-limiting cardiotoxicity. Vinorelbine is also available as oral formulation. In a multicenter phase II study, we analyzed the feasibility and the efficacy of a maximum of six cycles of i.v. epirubicin plus vinorelbine, followed by oral vinorelbine. We enrolled 30 patients with metastatic breast cancer. Each patient received epirubicin (75 mg/m2 on day 1) and vinorelbine (25 mg/m2 on days 1–8), every 3 weeks, for three cycles or six cycles in case of objective response or stable disease. When a clinical benefit was obtained, patients received oral vinorelbine (60 mg/m2 on days 1–8 every 3 weeks for three cycles). The regimen demonstrated to be active and well tolerated in metastatic breast cancer, and 6–8 months represented the optimal treatment duration. Maintenance therapy with oral vinorelbine was feasible, effective, safe and well accepted by the patients.

A combinational therapy of EGFR-CAR NK cells and oncolytic herpes simplex virus 1 for breast cancer brain metastases

Breast cancer brain metastases (BCBMs) are common in patients with metastatic breast cancer and indicate a poor prognosis. These tumors are especially resistant to currently available treatments due to multiple factors. However, the combination of chimeric antigen receptor (CAR)-modified immune cells and oncolytic herpes simplex virus (oHSV) has not yet been explored in this context. In this study, NK-92 cells and primary NK cells were engineered to express the second generation of EGFR-CAR. The efficacies of anti-BCBMs of EGFR-CAR NK cells, oHSV-1, and their combination were tested in vitro and in a breast cancer intracranial mouse model. In vitro, compared with mock-transduced NK-92 cells or primary NK cells, EGFR-CAR-engineered NK-92 cells and primary NK cells displayed enhanced cytotoxicity and IFN-γ production when co-cultured with breast cancer cell lines MDA-MB-231, MDA-MB-468, and MCF-7. oHSV-1 alone was also capable of lysing and destroying these cells. However, a higher cytolytic effect of EGFR-CAR NK-92 cells was observed when combined with oHSV-1 compared to the monotherapies. In the mice intracranially pre-inoculated with EGFR-expressing MDA-MB-231 cells, intratumoral administration of either EGFR-CAR-transduced NK-92 cells or oHSV-1 mitigated tumor growth. Notably, the combination of EGFR-CAR NK-92 cells with oHSV-1 resulted in more efficient killing of MDA-MB-231 tumor cells and significantly longer survival of tumor-bearing mice when compared to monotherapies. These results demonstrate that regional administration of EGFR-CAR NK-92 cells combined with oHSV-1 therapy is a potentially promising strategy to treat BCBMs.

Targeted multidrug delivery system to overcome chemoresistance in breast cancer

Chemotherapy has been widely used in breast cancer patients to reduce tumor size. However, most anticancer agents cannot differentiate between cancerous and normal cells, resulting in severe systemic toxicity. In addition, acquired drug resistance during the chemotherapy treatment further decreases treatment efficacy. With the proper treatment strategy, nanodrug carriers, such as liposomes/immunoliposomes, may be able to reduce undesired side effects of chemotherapy, to overcome the acquired multidrug resistance, and to further improve the treatment efficacy. In this study, a novel combinational targeted drug delivery system was developed by encapsulating antiangiogenesis drug bevacizumab into liposomes and encapsulating chemotherapy drug doxorubicin (DOX) into immunoliposomes where the human epidermal growth factor receptor 2 (HER2) antibody was used as a targeting ligand. This novel combinational system was tested in vitro using a HER2 positive and multidrug resistant breast cancer cell line (BT-474/MDR), and in vivo using a xenograft mouse tumor model. In vitro cell culture experiments show that immunoliposome delivery led to a high cell nucleus accumulation of DOX, whereas free DOX was observed mostly near the cell membrane and in cytoplasm due to the action of P-gp. Combining liposomal bevacizumab with immunoliposomal DOX achieved the best tumor growth inhibition and the lowest toxicity. Tumor size decreased steadily within a 60-day observation period indicating a potential synergistic effect between DOX and bevacizumab through the targeted delivery. Our findings clearly indicate that tumor growth was significantly delayed in the combinational liposomal drug delivery group. This novel combinational therapy has great potential for the treatment of patients with HER2/MDR double positive breast cancer.

Huaier aqueous extract suppresses human breast cancer cell proliferation through inhibition of estrogen receptor α signaling

Estrogen receptor α (ERα) has been reported to play a critical role in promoting the growth of breast tumor cells. In the present study, we explored the effect of Huaier extract on estrogen receptor α signaling in breast cancer cell lines. Our data demonstrated that Huaier extract effectively inhibited the proliferation of the MCF-7, T47D and ZR-75-1 human breast cancer cell lines. For the mechanism analysis, we demonstrated that Huaier extract significantly reduced the mRNA and protein levels of ERα in all three ERα-positive cell lines. The downregulation of ERα protein levels was correlated with activation of the proteasomes. We demonstrated that Huaier extract markedly decreased the expression of both ERα and its downstream genes, inhibited the estrogen-stimulated proliferation and reversed the estrogen-induced activation of the nuclear factor κB (NFκB) pathway. Our study provides evidence that Huaier extract is a novel estrogen receptor modulator and is a promising drug for the prevention and treatment of ERα-positive human breast cancers.

A three-arm randomized phase II study of oral vinorelbine plus capecitabine versus oral vinorelbine and capecitabine in sequence versus docetaxel plus capecitabine in patients with metastatic breast cancer previously treated with anthracyclines

Owing to the increased number of patients treated with anthracycline-based adjuvant chemotherapy, there is a need for new effective and tolerable nonanthracycline regimens in metastatic breast cancer. Patients with HER2-negative metastatic breast cancer previously treated with anthracyclines in (neo)adjuvant setting were randomized to fully oral 3 weekly cycles of the combination of oral vinorelbine with capecitabine (V + C), to the same drugs alternating every three cycles (V↔C), or to the combination of docetaxel and capecitabine (D + C). V was given at 80 mg/m(2) (after the first cycle at 60 mg/m(2)) on days 1 and 8 in the V + C arm and weekly in the V↔C arm, C at 1,000 mg/m(2) bid from days 1 to 14, and D on day 1 at 75 mg/m(2). The primary end point was disease control rate (CR + PR + NC ≥ 3 months). A total of 139 patients were randomly assigned to V + C (44 patients), V↔C (47 patients), and D + C (48 patients). After an independent review, the disease control rate in the intent-to-treat population in the V + C, V↔C, and D + C arms [95% CI] was 70.5% [54.8-83.2], 37.0% [23.2-52.5], and 70.8% [55.9-83.1], and the median overall survival 22.2, 19.4, and 24.2 months, respectively. When taken into account the disease control rate, the alternating V↔C regimen seems to be less effective compared with V + C or D + C combinations. Combinations of V + C or D + C showed similar efficacy and a different toxicity profile; V + C induced less neutropenia, infection, hand-foot syndrome, fatigue/asthenia, and alopecia, whereas D + C - less gastrointestinal toxicity. V + C combination constitutes a valuable fully oral alternative option to D + C in patients with metastatic breast cancer previously treated with anthracyclines in (neo)adjuvant setting, while offering the advantages of an all-oral treatment.

Phase II study of irinotecan plus capecitabine in anthracycline- and taxane- pretreated patients with metastatic breast cancer

To evaluate the efficacy and tolerability of combined treatment with irinotecan (I) and capecitabine (X), we conducted a phase II study of the IX combination in anthracycline- and taxane-pretreated patients with metastatic breast cancer (MBC). Patients received 80 mg/m(2) I on days 1 and 8 and 1,000 mg/m(2) X twice daily on days 1-14 of 21-day cycles until disease progression. The primary endpoint was the objective response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Thirty-six patients were enrolled between September 2006 and April 2008. The median follow-up was 47.6 months. The ORR was 58.3 % (95 % CI, 42.2-72.9), with 3 complete responses and 18 partial responses. The median PFS was 7.6 months (95 % CI, 5.0-10.2), and the median OS was 20.0 months (95 % CI, 11.6-28.4). Neutropenia was the most common adverse event (grade 3, 30.6 %; grade 4, 27.8 %) with febrile neutropenia in 2 patients (5.6 %). Three patients (8.3 %) had grade 3 diarrhea, 3 patients (8.3 %) had grade 3 asthenia, and 1 patient (2.8 %) had grade 3 hand-foot syndrome. The IX combination was effective and tolerable for anthracycline- and taxane-pretreated patients with MBC. A phase III trial of this combination is ongoing.

The Role of Interferon Regulatory Factor-1 (IRF1) in Overcoming Antiestrogen Resistance in the Treatment of Breast Cancer

Resistance to endocrine therapy is common among breast cancer patients with estrogen receptor alpha-positive (ER+) tumors and limits the success of this therapeutic strategy. While the mechanisms that regulate endocrine responsiveness and cell fate are not fully understood, interferon regulatory factor-1 (IRF1) is strongly implicated as a key regulatory node in the underlying signaling network. IRF1 is a tumor suppressor that mediates cell fate by facilitating apoptosis and can do so with or without functional p53. Expression of IRF1 is downregulated in endocrine-resistant breast cancer cells, protecting these cells from IRF1-induced inhibition of proliferation and/or induction of cell death. Nonetheless, when IRF1 expression is induced following IFNγ treatment, antiestrogen sensitivity is restored by a process that includes the inhibition of prosurvival BCL2 family members and caspase activation. These data suggest that a combination of endocrine therapy and compounds that effectively induce IRF1 expression may be useful for the treatment of many ER+ breast cancers. By understanding IRF1 signaling in the context of endocrine responsiveness, we may be able to develop novel therapeutic strategies and better predict how patients will respond to endocrine therapy.

The economic burden of metastatic breast cancer: a systematic review of literature from developed countries

OBJECTIVE

Breast cancer, the most common malignant cancer among women in Western countries, has poor prognosis following metastasis. New therapies potentially extend survival, but their value is questioned when benefits are incremental and expensive. The objective of our study was to understand the economic impact of metastatic breast cancer (MBC) and its treatment, and to evaluate the designs of these studies.

METHODS

We systematically reviewed the MEDLINE-indexed, English-language literature, identifying 31 articles on the economic evaluation of MBC in 10 developed countries, including studies of per-patient costs, gross national costs, and cost-effectiveness models. We also included health technology assessments (HTAs) from government and regulatory agencies.

RESULTS

Total per-patient costs of MBC are only available for Sweden ($17,301-$48,169 annually, depending on patient age (2005 USD)). Most economic analyses of per-patient direct costs originate from the US; across all countries, data indicate that this burden is substantial. Gross national costs of MBC are available only for the UK (cost of incident MBC cases is estimated to be $22 million annually (2002 GBP)). Many cost-effectiveness analyses suggest that a number of new and established treatments are cost-effective compared to standard care in various countries, but many offer small increments in survival. The cost-effectiveness of trastuzumab, capecitabine, and nab-paclitaxel has been evaluated in many recent studies.

CONCLUSION

Most economic evaluations of MBC have utilized secondary rather than primary data, and have used scenarios and assumptions which may be inaccurate or outdated. The quality of evidence disseminated to decision-makers could be improved by adherence to best practices in cost-effectiveness analyses.

Ixabepilone, a new treatment option for metastatic breast cancer

Patients with metastatic breast cancer (MBC) who develop resistance to anthracyclines and taxanes have limited therapeutic options. There is an unmet need for agents that can overcome tumor resistance and are effective in treating drug-resistant disease. The novel epothilone B analog, ixabepilone, binds to β-tubulin and stabilizes microtubules, leading to growth inhibition and apoptosis. Ixabepilone is able to overcome common mechanisms of resistance that limit the efficacy of many chemotherapeutic agents such as anthracyclines, taxanes, and capecitabine. Single-agent ixabepilone has clinical activity and a manageable safety profile against several different solid tumors including MBC, nonsmall cell lung cancer (NSCLC), and prostate cancer. Several phase II and III trials have demonstrated that ixabepilone-as monotherapy and in combination with capecitabine-is active in patients with pretreated or resistant MBC. Ixabepilone is the first epothilone approved for use as monotherapy or in combination with capecitabine in the treatment of metastatic or locally advanced breast cancer that is resistant or refractory to anthracyclines, taxanes, and/or capecitabine. Further clinical studies are evaluating the combination of ixabepilone with targeted agents such as trastuzumab or bevacizumab to further define the role of this novel agent in the treatment of MBC.

Chemotherapy resistance in metastatic breast cancer: the evolving role of ixabepilone

Resistance to chemotherapy is a major obstacle to the effective treatment of many tumor types. Although many anticancer therapies can alter tumor growth, in most cases the effect is not long lasting. Consequently, there is a significant need for new agents with low susceptibility to common drug resistance mechanisms in order to improve response rates and potentially extend survival. Approximately 30% of the women diagnosed with early-stage disease in turn progress to metastatic breast cancer, for which therapeutic options are limited. Current recommendations for first-line chemotherapy include anthracycline-based regimens and taxanes (paclitaxel and docetaxel). They typically give response rates of 30 to 70% but the responses are often not durable, with a time to progression of 6 to 10 months. Patients with progression or resistance may be administered capecitabine, gemcitabine, vinorelbine, albumin-bound paclitaxel, or ixabepilone, while other drugs are being evaluated. Response rates in this setting tend to be low (20 to 30%); the median duration of responses is <6 months and the results do not always translate into improved long-term outcomes. The present article reviews treatment options in taxane-resistant metastatic breast cancer and the role of ixabepilone in this setting.

Management of metastatic breast cancer: monotherapy options for patients resistant to anthracyclines and taxanes

Resistance to chemotherapeutic agents is a significant obstacle to the effective treatment of metastatic breast cancer (MBC). Anthracycline- and taxane-based regimens are active as first-line treatment for MBC; however, MBC often progresses because of primary or acquired resistance to anthracyclines and taxanes. There are few options for the treatment of patients with anthracycline- and taxane-resistant or taxane-refractory MBC. This article reviews several single agents that have demonstrated activity as treatment for patients with MBC who progress during, or rapidly following, treatment with anthracyclines and taxanes. Results from clinical trials evaluating agents such as ixabepilone, albumin-bound paclitaxel, capecitabine, vinorelbine, pemetrexed, and irinotecan are presented. Single-agent capecitabine is approved for the treatment of patients after failure of anthracyclines and taxanes. Ixabepilone has demonstrated efficacy in patients with MBC resistant to multiple chemotherapeutic agents and is the only agent approved by the Food and Drug Administration as monotherapy for anthracycline-, taxane-, and capecitabine-resistant MBC. Improved treatment strategies and further evaluation of newer agents may reduce the current burden of treatment-resistant or treatment-refractory MBC.

Implications of anthracycline-resistant and taxane-resistant metastatic breast cancer and new therapeutic options

Patients with advanced or metastatic breast cancer commonly develop disease resistant to chemotherapy (typically anthracyclines and taxanes), which presents a major obstacle to therapy and leaves few effective treatment options. Drug resistance can occur due to various mechanisms including modification of drug efflux membrane transporters such as P-glycoprotein, as well as alterations in beta-tubulin. The novel epothilone B analog, ixabepilone, which has low susceptibility to various drug-resistance mechanisms, has demonstrated preclinical activity in drug-resistant breast cancer. The clinical activity of ixabepilone was evaluated in metastatic breast cancer patients with highly pretreated and/or resistant/refractory disease. Results were reviewed from three phase II trials in which ixabepilone was administered as monotherapy and one phase III trial that evaluated ixabepilone in combination with capecitabine. As a single agent, ixabepilone demonstrated activity in women who were heavily pretreated and resistant to an anthracycline, a taxane, and/or capecitabine. The combination of ixabepilone and capecitabine was significantly more active than capecitabine alone in patients with prior treatment or resistance to anthracyclines and taxanes. Treatment-related adverse events were generally low grade except for grade 3/4 toxicities, including neutropenia (53-54%) and reversible peripheral sensory neuropathy (14-16%). Ixabepilone has significant activity in patients with heavily pretreated metastatic breast cancer who are disease resistant or refractory to anthracyclines and taxanes. Further clinical evaluation of this agent in patients with drug-resistant breast cancer and in specific patient subsets is warranted.

Survival data of patients with anthracycline- or taxane-pretreated or resistant metastatic breast cancer

Metastatic breast cancer is considered incurable. Despite effective response rates achieved with anthracycline or taxane anticancer drugs, cancers in approximately one third of patients fail to respond to first-line treatment with these agents. Patients who do respond show disease progression after a median of approximately 7-8 months. As a consequence, the development of new salvage treatments and strategies for metastatic breast cancer continues to be a high priority. However, few randomized controlled trials have been conducted in patients in whom previous treatment with anthracyclines and taxanes fails. Among those trials that have, few demonstrated an improvement in overall survival. Overall survival is considered the gold standard for evaluating the benefits of experimental cancer therapies. In addition, many investigators use progression-free survival or time to progression. Survival outcomes from large trials of newer combinations, such as ixabepilone plus capecitabine and gemcitabine plus vinorelbine, are encouraging. They have shown significant benefits in terms of progression-free survival, and they have revealed demonstrable benefits for several hard-to-treat subgroups of patients with metastatic breast cancer. Addition of the targeted agents trastuzumab, bevacizumab, and lapatinib to chemotherapy has produced significant benefits in time to progression and progression-free survival. Ongoing research should help in determining which patients are likely to benefit from such agents when first- or second-line therapy fails and in ascertaining whether this therapy can be optimized to maximize therapeutic potential and minimize unnecessary toxicity.

PET and PET-CT Imaging in Treatment Monitoring of Breast Cancer

Breast cancer is one of the more responsive solid tumors with a wide range of systemic therapy options. The treatment of newly diagnosed breast cancer is primarily determined by the extent of disease and generally includes surgery, radiation, and chemotherapy. This article discusses the PET and PET-CT modalities for evaluating treatment response in breast cancer.

Management of advanced breast cancer with the epothilone B analog, ixabepilone

Despite the activity of standard chemotherapies in advanced breast cancer, disease progression remains inevitable. Most patients exposed to anthracyclines and taxanes develop resistance and a significant subset shows primary resistance. The increasing use of these agents as adjuvant therapy may result in more anthracycline- and taxane-resistant patients in the metastatic setting; few treatment options are available for patients with metastatic breast cancer (MBC) resistant to multiple chemotherapies. The heterogeneity of breast cancer represents another therapeutic challenge. Breast cancers may be classified as luminal, human epidermal growth factor 2 (HER2)-positive, or estrogen receptor-, progesterone receptor-, and human epidermal growth factor 2-negative (ER/PR/HER2-negative, triple negative). HER2-positive and ER/PR/HER2-negative tumors are associated with poor prognosis owing to aggressive disease and poor long-term response to therapy. The epothilone B analog ixabepilone has low susceptibility to multiple mechanisms of resistance and has demonstrated activity in patients with MBC resistant to anthracyclines, taxanes, and/or capecitabine. Ixabepilone is the first epothilone to be approved, as monotherapy or in combination with capecitabine, for treatment of resistant/refractory MBC or locally advanced breast cancer. Treatment with ixabepilone is an option for patients with ER/PR/HER2-negative or HER2-positive disease and/or primary resistance to taxanes.

Activity of ixabepilone in patients with metastatic breast cancer with primary resistance to taxanes

Primary drug resistance, defined as disease progression as best response to treatment, presents an important problem in everyday clinical practice. Primary taxane resistance, reported in up to 55% of patients with breast cancer, plays a critical role in minimizing the efficacy of taxane-based chemotherapy for metastatic breast cancer (MBC). The epothilones are a novel class of antineoplastic agents, developed to overcome tumor-resistance mechanisms. Ixabepilone, the first drug in this class, stabilizes microtubule polymerization, and induces cell-cycle arrest and apoptosis. Ixabepilone demonstrates low susceptibility to different and multiple mechanisms of drug resistance that play a crucial role in primary taxane resistance, such as tumor overexpression of neuronal-specific beta-tubulin isotype III and drug-efflux transporters. In phase II trials, ixabepilone demonstrated proven activity in patients with MBC whose tumors had primary or secondary resistance to taxanes and other agents. Ixabepilone also demonstrated activity in patients with tumor types such as renal-cell cancer and pancreatic cancer that are usually intrinsically insensitive to chemotherapy, including taxanes. To determine the activity of ixabepilone in patients with primary taxane resistance, a retrospective analysis of patient subsets from 2 clinical trials was conducted. Ixabepilone demonstrated clinical activity as monotherapy, and in combination with capecitabine, in patients with MBC who had disease progression as best response to previous taxane therapy. Response rates in patients with primary taxane resistance were comparable to responses observed in total patient populations. The clinical results support the hypothesis that ixabepilone can overcome or circumvent primary mechanisms of resistance to taxanes and other chemotherapeutic agents.

The influence of endocrine treatments for breast cancer on health-related quality of life

Many hormonal modalities are available for breast cancer treatment, such as selective oestrogen receptor modulators (SERMs), aromatase inhibitors, progestins and luteinising hormone-releasing hormone (LHRH) agonists. The long-term impact of these endocrine manipulations is an issue, because the duration of adjuvant treatment is still increasing, as is the number of breast cancer survivors. Premature menopause is induced at a young age, and may often be permanent after chemotherapy. The purpose of this review is to provide a literature-based overview of the side effects of endocrine treatment in pre- and postmenopausal breast cancer patients and the influence on HRQoL, especially on sexual functioning. The collection of health-related quality of life (HRQoL) data can result in better treatment recommendations during endocrine therapy.

METHODS

This review was limited to prospective randomised studies in English literature from between 1977 and 2007 and provides an overview of the effects on HRQoL and sexuality of various hormonal treatment in pre- and postmenopausal breast cancer patients, both in the adjuvant and palliative setting. Relevant clinical studies were identified by using the Medline database.

RESULTS

HRQoL mostly is severely influenced by chemotherapy and part of these symptoms may be lasting, especially when associated with the induction of premature menopause. Similar symptoms may be encountered during ovarian suppression therapy by LHRH analogs, but they will usually prove to be reversible. The varying side effect profiles of tamoxifen and aromatase inhibitors did not lead to significant difference in overall HRQoL. HRQoL during progestins and the SERM fulvestrant has been compared to this during aromatase inhibitors, and a large number of studies on HRQoL during endocrine therapy will be discussed.

Quality of life in metastatic breast cancer patients under chemotherapy or supportive care: a single-institution comparative study

The aim of the present study was to evaluate quality of life (QoL) parameters in patients with metastatic breast cancer (MBC) and assess the potential differences between patients receiving chemotherapy and those undergoing supportive care interventions. In total, 210 women with MBC were enrolled in this prospective, randomized, single-institution study. The primary outcome of the trial was QoL assessment, using the self-administered European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30, version 3) and Quality of Life Questionnaire Breast 23 (QLQ-BR23) questionnaires. Quality of life was found to be statistically better (P = 0.008) in MBC patients receiving chemotherapy than those under only supportive care. Statistically significant differences in favour of chemotherapy were also found in functioning subscales, symptom single-item questions and sexual functioning. Our findings suggest that chemotherapy in MBC patients with good performance status is the more rational therapeutic approach in terms of QoL improvement.

Oral vinorelbine: role in the management of metastatic breast cancer

The treatment of advanced breast cancer is continually evolving, with the aim of improving the quality and duration of remission and, in some instances, survival. In this setting, the importance of quality of life cannot be underestimated, and growing attention is being paid to treatment convenience and compliance. New anticancer agents have improved efficacy, but for many of them, toxicity often remains a problem. Vinorelbine seems to represent both an active and a well tolerated treatment for metastatic breast cancer. In particular, the oral formulation has similar efficacy to that of the injectable formulation and has demonstrated generally favourable tolerability, with a high degree of acceptance by both patients and physicians. The availability of this and other novel, well tolerated and effective treatments provides greater potential to tailor treatment to meet individual patient needs and, therefore, also provide the potential to improve patient outcomes. Preliminary data suggest that oral vinorelbine may permit continued, effective chemotherapy when further parenteral therapy with more intensive and more toxic agents is considered inappropriate. Early findings also suggest that oral vinorelbine, when administered together with another new oral agent, capecitabine, may be a valid choice in metastatic breast cancer treatment. Furthermore, vinorelbine plus the monoclonal antibody trastuzumab, with or without oral capecitabine, appears to be another regimen that may be worthy of additional study in patients with human epidermal growth factor-2 positive advanced breast cancer.

Comparative analysis of xanafide cytotoxicity in breast cancer cell lines

Xanafide, a DNA-intercalating agent and topoisomerase II inhibitor, has previously demonstrated comparable cytotoxicity to the parent drug amonafide (NSC 308847). The current study was conducted to investigate further the anti-proliferative effects of xanafide in human breast cancer cell lines, in vitro and in vivo. The in vitro activity of xanafide against MCF-7, MDA-MB-231, SKBR-3 and T47D cell lines was compared to that of paclitaxel, docetaxel, gemcitabine, vinorelbine and doxorubicin. In MCF-7, xanafide demonstrated comparable total growth inhibition (TGI) concentrations to the taxanes and lower TGI values than gemcitabine, vinorelbine and doxorubicin. MCF-7 (oestrogen receptor (ER)+/p53 wild-type) was the most sensitive cell line to xanafide. MDA-MB-231 and SKBR-3 exhibited similar sensitivity to xanafide. T47 D (ER+/p53 mutated), showed no response to this agent. The in vivo activity of xanafide was further compared to that of docetaxel in MCF-7 and MDA-MB-231 cell lines using the hollow fibre assay. Xanafide was slightly more potent than docetaxel, at its highest dose in MCF-7 cell line, whereas docetaxel was more effective than xanafide in MDA-MB-231 cell line. Our results show that there is no relationship between sensitivity of these cell lines to xanafide and cellular levels of both isoforms of topoisomerase II and suggest that ER and p53 status and their crosstalk may predict the responsiveness or resistance of breast cancer patients to xanafide.

The circadian rhythm of biochemical markers of bone resorption is normally synchronized in breast cancer patients with bone lytic metastases independently of tumor load

BACKGROUND

Bone metastases are devastating events resulting in disruption of local bone remodeling processes. Physiological bone turnover has a circadian rhythm. No data are available on the circadian pattern of bone turnover markers in patients with bone metastases.

METHODS

Twenty post-menopausal women with breast cancer (BC) at first disease relapse and at least one bone metastasis were consecutively recruited. Twenty healthy women served as controls. Patients were free from concomitant chemotherapy/endocrine therapy. Throughout a 24-h period, urine samples were collected at 4-h intervals, and blood samples were collected at 4-h intervals between 08:00 and 24:00, and at 2-h intervals between 24:00 and 08:00. Serum osteocalcin (OC), total and bone-alkaline phosphatase (tALP and bALP, respectively) and C-terminal telopeptide of type I collagen (CTX), and urinary NTX and free deoxypyridinoline (fDPD) were measured together with serum parathyroid hormone (PTH) and serum and urinary calcium and phosphorus. Temporal variations of measured analytes were assessed by ANOVA and the COSINOR model.

RESULTS

At 08:00, patients had higher levels of bone resorption indices (NTX, CTX and fDPD) than controls (p<0.0001). tALP and bALP, but not OC, were higher in patients than controls (p<0.001). PTH, serum and urinary calcium and urinary phosphorus did not differ between groups; serum phosphorus was higher in controls (p<0.0001). A circadian rhythm was evident for CTX and fDPD values in both patients and controls. A circadian rhythm in NTX, OC, phosphorus and PTH was apparent in controls only. However, it was detected also in patients when percent changes from MESOR were considered. Serum phosphorus showed a circadian rhythm, while no rhythm was detected for tALP, bALP, serum and urinary calcium. The rhythmicities in cancer patients were normally synchronized, and rhythmic parameters were independent of tumor load in the skeleton, age and menopausal status.

CONCLUSIONS

This is the first study to yield information on the maintenance of the temporal program of bone turnover in bone metastatic cancer patients. Whether administration of bisphosphonates in the nighttime leads to a different outcome with respect to the current administration in the morning is a matter of future research.

Sulindac Sulfide and Exisulind Inhibit Expression of the Estrogen and Progesterone Receptors in Human Breast Cancer Cells

In previous studies, we found that sulindac sulfide and exisulind (sulindac sulfone, Aptosyn) cause growth inhibition, arrest cells in the G1 phase of the cell cycle, and induce apoptosis in human breast cancer cell lines. These effects were associated with decreased expression of cyclin D1. The present study focuses on the effects of sulindac sulfide and exisulind on hormone signaling components in breast cancer cells. We found that estrogen receptor (ER)-positive and progesterone receptor (PR)-positive T47D breast cancer cells were somewhat more sensitive to growth inhibition by sulindac sulfide or exisulind than ER-negative PR-negative MB-MDA-468 breast cancer cells. Further studies indicated that sulindac sulfide and exisulind caused marked down-regulation of expression of the ER and PR-A and PR-B in T47D cells. However, neither compound caused a major change in expression of the retinoic acid receptor alpha (RARalpha), RARbeta, or RARalpha in T47D cells. Sulindac sulfide and exisulind also caused a decrease in expression of the ER in estrogen-responsive MCF-7 breast cancer cells. Both compounds also markedly inhibited estrogen-stimulated activation of an estrogen-responsive promoter in transient transfection reporter assays. Treatment of T47D cells with specific protein kinase G (PKG) activators did not cause a decrease in ER or PR expression. Therefore, although sulindac sulfide and exisulind can cause activation of PKG, the inhibitory effects of these two compounds on ER and PR expression does not seem to be mediated by PKG. Our findings suggest that the growth inhibition by sulindac sulfide and exisulind in ER-positive and PR-positive human breast cancer cells may be mediated, in part, by inhibition of ER and PR signaling. Thus, these and related compounds may provide a novel approach to the prevention and treatment of human breast cancers, especially those that are ER positive.

Role of trastuzumab in adjuvant therapy for locally invasive breast cancer

PURPOSE

The role of trastuzumab in adjuvant therapy for locally invasive breast cancer is discussed.

SUMMARY

Trastuzumab is a humanized monoclonal antibody that binds to the extracellular domain of human epidermal growth factor receptor-2 (HER2). Currently, trastuzumab is indicated for use in HER2-positive patients with metastatic breast cancer. Because trastuzumab specifically targets a receptor that is overexpressed in tumor cells, it is less likely to cause the cytotoxic adverse effects of traditional chemotherapy. Cardiotoxicity has been a major concern, however. Several trials were started to evaluate trastuzumab in the adjuvant setting in patients diagnosed with early-stage breast cancer. The interim results of these trials have shown a promising effect of adjuvant therapy with trastuzumab in improving overall survival, disease-free survival, relapse-free survival, and distant-disease-free survival.

CONCLUSION

The use of trastuzumab as adjuvant therapy in patients with HER2-positive breast cancer can lead to increased survival. The appropriateness of trastuzumab therapy should be considered based on HER2 status, cost, and risk of toxicity.

Effect of resveratrol on angiogenesis and platelet/fibrin-accelerated tumor growth in the chick chorioallantoic membrane model

We carried out this investigation to examine the effects on angiogenesis-mediated processes and to define anti-angiogenesis mechanisms for flavonoids. We examined the effects and mechanisms of the flavonoid resveratrol on angiogenesis and tumor growth using the chick chorioallantoic membrane (CAM) model of angiogenesis, the CAM tumor growth model, and the effect on p53 in fibroblast growth factor-2 (FGF2) stimulated human endothelial cells using immunoassay. Resveratrol demonstrated potent inhibition (effective dose50=0.7+/-0.1 microM) of FGF2-induced angiogenesis and tumor growth. Furthermore, resveratrol significantly (P<0.01) inhibited platelet/fibrin clot-promoted human colon and fibrosarcoma tumor growth in the CAM tumor model. Resveratrol in a concentration-dependent (1-3 microM) manner significantly promoted apoptosis in FGF2-stimulated endothelial cells by increasing p53 protein production. These data indicated potent anti-angiogenesis efficacy, inhibition of tumor growth, and clot-mediated enhanced tumor growth. These data suggest potential anticancer benefits as a chemopreventive and chemotherapeutic for the flavonoid resveratrol.

Extending survival with chemotherapy in metastatic breast cancer

Metastatic breast cancer (MBC) remains essentially incurable, and goals of therapy include the palliation of symptoms, delay of disease progression, and prolongation of overall survival time without negatively impacting quality of life. Anthracycline and taxane-based therapies have traditionally shown the highest degree of activity in MBC. Though numerous randomized clinical trials have shown improvements in overall response rates, few have found clear survival benefits. In recent years, however, there has been a small but growing series of clinical trials demonstrating modest, but meaningful survival advantages in metastatic disease. A common feature in many of these trials has been the use of a taxane, and more recently, a taxane combined with an antimetabolite. In addition, the development of targeted biologic agents active against MBC, such as trastuzumab and bevacizumab, has demonstrated great potential for enhancing the effects of chemotherapy and producing meaningful survival improvements. The role of the taxanes, antimetabolites, and biologics in extending survival in MBC is discussed.

Gemcitabine in combination with paclitaxel for the treatment of metastatic breast cancer

Gemcitabine and paclitaxel are active drugs in the treatment of patients with metastatic breast cancer which seem to have synergistic anticancer activity. Seven Phase II trials of gemcitabine/paclitaxel and one Phase III trial have been published. Two dosing or admistration schedules have been preferred in the clinical development of the combinations: gemcitabine on days 1 and 8 plus paclitaxel on day 1 or 8, every 3 weeks or gemcitabine plus paclitaxel on day 1, every 2 weeks. In first-line Phase II trials, up to 71% of patients responded to gemcitabine/paclitaxel therapy. Response rates were lower among patients who had received previous chemotherapy for metastatic disease (46%). Responses were observed in patients refractory to docetaxel monotherapy. Toxicity of gemcitabine/paclitaxel regimens has been low, with infrequent neutropenia or nonhematologic toxicity. In the randomized Phase III registration trial, the gemcitabine/paclitaxel combination demonstrated a clear advantage over paclitaxel alone in terms of the primary end point of survival and other efficacy end points, with manageable toxicity. Gemcitabine/paclitaxel showed a survival advantage of approximately 22% over paclitaxel alone (hazard ratio of 0.775). Gemcitabine plus paclitaxel represents an active and well-tolerated treatment alternative for first-line treatment of anthracycline-treated metastatic breast cancer. Triplet combinations, in which an anthracycline or trastuzumab are added to gemcitabine/paclitaxel, are being explored in the metastatic and neoadjuvant settings with excellent results. In addition, gemcitabine/paclitaxel is being evaluated in two large adjuvant multicenter studies.