Adjuvant endocrine therapy for women with hormone receptor-positive breast cancer: american society of clinical oncology clinical practice guideline focused update

Phenotype anchoring in zebrafish reveals a potential role for matrix metalloproteinases (MMPs) in tamoxifen's effects on skin epithelium

The zebrafish is a powerful alternative model used to link phenotypes with molecular effects to discover drug mode of action. Using a zebrafish embryo-larval toxicity bioassay, we evaluated the effects of tamoxifen--a widely used anti-estrogen chemotherapeutic. Zebrafish exposed to ≥ 10 μM tamoxifen exhibited a unique necrotic caudal fin phenotype that was rapidly induced regardless of developmental life-stage when treatment was applied. To define tamoxifen's bioactivity resulting in this phenotype, targeted gene expression was used to evaluate 100 transcripts involved in tissue remodeling, calcium signaling, cell cycle and cell death, growth factors, angiogenesis and hypoxia. The most robustly misregulated transcripts in the tail were matrix metalloproteinases mmp9 and mmp13a, induced 127 and 1145 fold, respectively. Expression of c-fos, c-jun, and ap1s1 were also moderately elevated (3-7 fold), consistent with AP-1 activity--a transcription factor that regulates MMP expression. Immunohistochemistry confirmed high levels of induction for MMP13a in affected caudal fin skin epithelial tissue. The necrotic caudal fin phenotype was significantly attenuated or prevented by three functionally unique MMP inhibitors: EDTA (metal chelator), GM 6001 (broad MMP inhibitor), and SR 11302 (AP-1 transcription factor inhibitor), suggesting MMP-dependence. SR 11302 also inhibited induction of mmp9, mmp13a, and a putative MMP target, igfbp1a. Overall, our studies suggest that tamoxifen's effect is the result of perturbation of the MMP system in the skin leading to ectopic expression, cytotoxicity, and the necrotic caudal fin phenotype. These studies help advance our understanding of tamoxifen's non-classical mode of action and implicate a possible role for MMPs in tissues such as skin.

Adjuvant Endocrine Therapy for Women With Hormone Receptor-Positive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update on Ovarian Suppression

PURPOSE

To update the ASCO adjuvant endocrine therapy guideline based on emerging data concerning the benefits and risks of ovarian suppression in addition to standard adjuvant therapy in premenopausal women with estrogen receptor-positive breast cancer.

METHODS

ASCO convened an Update Panel and conducted a systematic review of randomized clinical trials investigating ovarian suppression.

RESULTS

Two trials investigating the addition of ovarian suppression to tamoxifen did not show an overall clinical benefit for ovarian suppression. Nonetheless, the addition of ovarian suppression to standard adjuvant therapy with tamoxifen or with an aromatase inhibitor improved disease-free survival and improved freedom from breast cancer and distant recurrence compared with tamoxifen alone among the subset of patients who were at sufficient risk for recurrence such that adjuvant chemotherapy was warranted. Compared with tamoxifen alone, ovarian suppression was associated with a substantial increase in menopausal symptoms, sexual dysfunction, and diminished quality of life.

RECOMMENDATIONS

The Panel recommends that higher-risk patients should receive ovarian suppression in addition to adjuvant endocrine therapy, whereas lower-risk patients should not. Women with stage II or III breast cancers who would ordinarily be advised to receive adjuvant chemotherapy should receive ovarian suppression with endocrine therapy. The panel recommends that some women with stage I or II breast cancers at higher risk of recurrence who might consider chemotherapy may also be offered ovarian suppression with endocrine therapy. Women with stage I breast cancers not warranting chemotherapy should not receive ovarian suppression, nor should women with node-negative cancers 1 cm or less. Ovarian suppression may be administered with either tamoxifen or an aromatase inhibitor. Additional information is available at www.asco.org/guidelines/endocrinebreast and www.asco.org/guidelineswiki.

Identification of a highly immunogenic mouse breast cancer sub cell line, 4T1-S

Cancer vaccines serve as a promising clinical immunotherapeutic strategy that help to trigger an effective and specific antitumor immune response compared to conventional therapies. However, poor immunogenicity of tumor cells remains a major obstacle for clinical application, and developing new methods to modify the immunogenicity of tumor cells may help to improve the clinical outcome of cancer vaccines. 4T1 mouse breast cancer cell line has been known as poorly immunogenic and highly metastatic cell line. Using this model, we identified a sub cell line of 4T1-designated as 4T1-Sapporo (4T1-S)-which shows immunogenic properties when used as a vaccine against the same line. In 4T1-S-vaccinated mice, subcutaneous injection of 4T1-S resulted in an antitumor inflammatory response represented by significant enlargement of draining lymph nodes, accompanied with increased frequencies of activated CD8 T cells and a subpopulation of myeloid cells. Additionally, 4T1-S vaccine was ineffective to induce tumor rejection in nude mice, which importantly indicate that 4T1-S vaccine rely on T cell response to induce tumor rejection. Further analysis to identify mechanisms that control tumor immunogenicity in this model may help to develop new methods for improving the efficacies of clinical cancer vaccines.

Second-line single-agent chemotherapy in human epidermal growth factor receptor 2-negative metastatic breast cancer: A systematic review

BACKGROUND

No 'gold standard' exists for single-agent chemotherapy of human epidermal growth factor receptor 2-negative (HER2-negative) metastatic breast cancer (MBC) in the second-line. The objective of this systematic review is to identify and appraise overall survival (OS), progression-free survival (PFS), time to progression (TTP) and Grade ≥3 adverse event evidence for single-agent chemotherapy in this setting.

METHODS

MEDLINE, Embase and the Cochrane Library were searched to October 2013, and PubMed October 2013 to November 2014. Electronic database searches were supplemented with hand searching of reference lists and conferences. Eligible randomised controlled trials (RCTs) employed at least one single-agent chemotherapy treatment, enrolled HER2-negative or unselected MBC patients who had progressed following first-line chemotherapy within the metastatic setting, and reported outcomes of interest for the second-line setting.

RESULTS

Fifty-three RCTs were included in total, with most containing mixed populations by HER2 status and treatment line. Fourteen studies reported data specifically for second- and later-line treatment within the metastatic setting. Median overall survival (OS) in most trials was 8-13 months. Only one trial reported a significant difference between studied interventions in the second-line metastatic setting: nab-paclitaxel (n=131) conferred a statistically significant OS advantage vs. three-weekly paclitaxel (n=136) (median OS 13.0 vs. 10.7 months, respectively; hazard ratio 0.73, p=0.024) and improved overall safety.

CONCLUSION

One RCT demonstrated significant benefit in this setting in confirmed HER2-negative MBC alongside favourable safety. Treatment line terminology was imprecise. To reliably inform patient treatment decisions, quality-of-life data are needed and precise OS estimation according to underlying patient characteristics.

Indications for prognostic gene expression profiling in early breast cancer

OPINION STATEMENT

Breast cancer is a heterogeneous disease. While breast cancer mortality has dropped substantially over the past three decades due to early detection and adjuvant systemic therapy (AST), the risk of recurrence is highly dependent upon numerous factors including tumor size, involvement of regional lymph nodes, histologic grade, expression of hormone receptors (estrogen and progesterone), and human epidermal growth factor receptor 2 (HER2) amplification. We use these factors to determine which early breast cancer (EBC) patients should be treated with AST, including endocrine therapy (ET), chemotherapy, and HER2-directed treatments. While these factors aid in this determination, it remains challenging to identify those patients unlikely to benefit from adjuvant chemotherapy, resulting in over-treatment of patients. Given this dilemma, there has been great interest in the development of prognostic and predictive gene expression profiles. The most extensively studied profile, the 21-gene recurrence score (Oncotype Dx®), estimates 10-year risk of breast cancer recurrence in patients with estrogen receptor (ER)-positive, HER2-negative, node-negative EBC and is likely predictive of chemotherapy benefit. This assay has established analytic validity, clinical validity, and clinical utility for this patient group and, therefore, is indicated in this patient population to help inform decisions regarding administration of adjuvant chemotherapy. Several other assays may have utility in this clinical context or perhaps to identify patients who do not require extended adjuvant ET. These assays include the following: PAM 50 Risk of Recurrence (ROR) Score (Prosigna™), Breast Cancer Index, and EndoPredict®.

A Retrospective Study on the Efficacy of Trastuzumab in HER2-Positive and Tamoxifen-Refractory Breast Cancer with Brain Metastasis

BACKGROUND AND OBJECTIVE

The role of trastuzumab in breast cancer with brain metastasis is still in discussion. This study was conducted to investigate the efficacy of trastuzumab in the management of human epidermal growth factor receptor 2 (HER2)-positive, tamoxifen-refractory breast cancer with brain metastasis.

METHODS

This retrospective study was conducted between January 2008 and December 2012. A total of 33 patients receiving trastuzumab treatment for HER2-positive, tamoxifen-refractory breast cancer with brain metastasis were assigned to the experimental group, while a matched group of 35 patients who received systemic therapy without trastuzumab were assigned to the control group. Data on the patient characteristics and clinical outcomes were collected and evaluated.

RESULTS

Patients in the trastuzumab group showed a significantly better response to treatment than those in the control group (p = 0.025). Univariate and multivariate Cox proportional regression analyses indicated that progression-free survival was significantly longer in patients receiving trastuzumab therapy than in the control group (hazard ratio [HR] 2.213 [p = 0.003] and HR 3.056 [p < 0.001], respectively) and significantly shorter in patients with two or more extracranial metastases (HR 0.417 [p = 0.002] and HR 0.317 [p < 0.001], respectively). Furthermore, patients on trastuzumab treatment experienced longer overall survival than patients in the control group (HR 2.844 [p < 0.001] and HR 4.017 [p < 0.001], respectively), while shorter overall survival was seen in patients with two or more extracranial metastases (HR 0.524 [p = 0.021] and HR 0.430 [p = 0.005], respectively) and in those receiving capecitabine-based therapy as compared with anthracycline-based therapy (HR 0.558 [p = 0.030] and HR 0.449 [p = 0.011], respectively).

CONCLUSION

Trastuzumab was found to benefit patients with HER2-positive, tamoxifen-refractory breast cancer with brain metastasis by improving progression-free and overall survival.

Targeted therapies with companion diagnostics in the management of breast cancer: current perspectives

Breast cancer is a multifaceted disease exhibiting both intertumoral and intratumoral heterogeneity as well as variable disease course. Over 2 decades of research has advanced the understanding of the molecular substructure of breast cancer, directing the development of new therapeutic strategies against these actionable targets. In vitro diagnostics, and specifically companion diagnostics, have been integral in the successful development and implementation of these targeted therapies, such as those directed against the human epidermal growth factor receptor 2. Lately, there has been a surge in the development, commercialization, and marketing of diagnostic assays to assist in breast cancer patient care. More recently, multigene signature assays, such as Oncotype DX, MammaPrint, and Prosigna, have been integrated in the clinical setting in order to tailor decisions on adjuvant endocrine and chemotherapy treatment. This review provides an overview of the current state of breast cancer management and the use of companion diagnostics to direct personalized approaches in the treatment of breast cancer.

Impact of Adjuvant Endocrine Therapy on Quality of Life and Symptoms: Observational Data Over 12 Months From the Mind-Body Study

PURPOSE

To examine patterns of health and symptoms associated with the initiation of adjuvant endocrine therapy (ET) for primary breast cancer treatment.

PATIENTS AND METHODS

The mind-body study (MBS) observational cohort participants provided self-reported data on physical and mental health, ET-related symptoms, as well as depression, fatigue, and sleep obtained at enrollment (after primary treatment, prior to initiation of ET) and 6 and 12 months later. Longitudinal trajectories of outcome variables among three patient groups (no ET, aromatase inhibitor [AI], or tamoxifen) were compared by using linear mixed models.

RESULTS

Two-thirds of the 186 women initiated ET, which was evenly split between AI and tamoxifen, and no significant differences were observed in self-reported measures among the groups at baseline or in covariate-adjusted analyses. Physical health scores were below normative levels initially and improved over time, but the AI group had a significantly lower score at 12 months (P = .05); mental health scores were within the normal range, were similar in each group, and did not change over time. The no-ET group showed either stable or declining symptom severity, whereas the ET groups often showed increased severity over time, and the AI group reported more severe musculoskeletal (P = .02), hot flash (P = .02), and cognitive problems (P = .006) at one or both of the follow-up time points compared with the no-ET group. The tamoxifen group had higher levels of hot flashes (P = .002), cognitive problems (P = .016), and bladder problems (P = .02) than the no-ET group.

CONCLUSION

Attention should be given to the increased symptom burden associated with ET, and better efforts should be made to address patient-reported outcomes.

PET Imaging of Breast Cancer: Role in Patient Management

Breast cancer is the most common malignancy in females. Imaging plays a critical role in diagnosis, staging and surveillance, and management of disease. Fluorodeoxyglucose (FDG) PET the imaging is indicated in specific clinical setting. Sensitivity of detection depends on tumor histology and size. Whole body FDG PET can change staging and management. In recurrent disease, distant metastasis can be detected. FDG PET imaging has prognostic and predictive value. PET/MR is evolving rapidly and may play a role management, assessment of metastatic lesions, and treatment monitoring. This review discusses current PET modalities, focusing on of FDG PET imaging and novel tracers.

Assessing cost-utility of predictive biomarkers in oncology: a streamlined approach

Evaluation of cost-utility is critical in assessing the medical utility of predictive or prognostic biomarkers. Current methods involve complex state-transition models, requiring comprehensive data inputs. We propose a simplified decision-analytic tool to explore the relative effect of factors contributing to the cost-utility of a biomarker. We derived a cost-utility metric, the "test incremental cost-effectiveness ratio" (TICER) for biomarker-guided treatment compared to no biomarker use. This method uses data inputs readily accessible through clinical literature. We compared our results with traditional cost-effectiveness analysis of predictive biomarkers for established (HER2-guided trastuzumab, ALK-guided crizotinib, OncotypeDX-guided adjuvant chemotherapy) and emerging (ROS1-guided crizotinib) targeted treatments. We conducted sensitivity analysis to determine which factors had the greatest impact on TICER estimates. Base case TICER for HER2 was $149,600/quality-adjusted life year (QALY), for ALK was $22,200/QALY, and for OncotypeDX was $11,600/QALY, consistent with literature-reported estimates ($180,000/QALY, $202,800/QALY, $8900/QALY, respectively). Base case TICER for ROS1-guided crizotinib was $205,900/QALY. Generally, when treatment cost is considerably greater than biomarker testing costs, TICER is driven by clinical outcomes and health-related quality of life, while biomarker prevalence and treatment cost have a lesser effect. Our simplified decision-analytic approach produces values consistent with existing cost-effectiveness analyses. Our results suggest that biomarker value is mostly driven by the clinical efficacy of the targeted agent. A user-friendly web tool for complete TICER analysis has been made available for open use at http://medicine.yale.edu/lab/pusztai/ticer/ .

Histone deacetylase inhibitors for the treatment of cancer stem cells

HDAC inhibitors are a promising group of epigenetic drugs that show the ability to induce apoptosis in cancer stem cells.

The best of both worlds - managing the cancer, saving the bone

In the context of breast cancer, the importance of the skeleton in the regulation of primary tumour development and as a site for subsequent metastasis is well characterized. Our understanding of the contributions made by the host bone and bone marrow cells increasingly demonstrates the extent of the interaction between tumour cells and normal host cells. As a result, the need to develop and utilize therapies that can impede the growth and/or function of tumour cells while sparing normal host bone and bone marrow cells is immense and expanding. The need for these new treatments is, however, superimposed on the orthopaedic management of patients' quality of life, where pain control and continued locomotion are paramount. Indeed, the majority of the anticancer therapies used to date often result in direct or indirect damage to bone. Thus, although the bone microenvironment regulates tumour cell growth in bone, cells within the bone marrow niche also mediate many of the orthopaedic consequences of tumour progression as well as resistance to the antitumour effects of existing therapies. In this Review, we highlight the effects of existing cancer treatments on bone and the bone marrow microenvironment as well as the mechanisms mediating these effects and the current utility of modern orthopaedic interventions.

Endocrine therapy in premenopausal women with breast cancer: a critical appraisal of current evidence

Nearly 60% of all breast cancer premenopausal women are diagnosed with a hormone receptor positive tumor and, therefore, are candidates for adjuvant hormonal therapy. Treatment with tamoxifen for at least 5 years has been for a long time the standard of care, as it is associated with overall positive clinical outcomes. However, in the last decade, a number of studies on adjuvant endocrine therapy in premenopausal women with hormone receptor positive breast cancer have been published, adding a bulk of evidence to existing knowledge in this field. A critical appraisal of their results appears necessary in order to put the recently collected data into the current framework of treatment, and to discuss the several issues that remain open. Here, we review the most recent evidence on the following: the optimal duration of tamoxifen treatment, results of the studies comparing tamoxifen alone to tamoxifen plus ovarian function suppression (OFS), results of the studies comparing tamoxifen plus OFS to aromatase inhibitors plus OFS.

Soy Isoflavones and Breast Cancer Cell Lines: Molecular Mechanisms and Future Perspectives

The potential benefit of soy isoflavones in breast cancer chemoprevention, as suggested by epidemiological studies, has aroused the interest of numerous scientists for over twenty years. Although intensive work has been done in this field, the preclinical results continue to be controversial and the molecular mechanisms are far from being fully understood. The antiproliferative effect of soy isoflavones has been commonly linked to the estrogen receptor interaction, but there is growing evidence that other pathways are influenced as well. Among these, the regulation of apoptosis, cell proliferation and survival, inhibition of angiogenesis and metastasis or antioxidant properties have been recently explored using various isoflavone doses and various breast cancer cells. In this review, we offer a comprehensive perspective on the molecular mechanisms of isoflavones observed in in vitro studies, emphasizing each time the dose-effect relationship and estrogen receptor status of the cells. Furthermore, we present future research directions in this field which could provide a better understanding of the inner molecular mechanisms of soy isoflavones in breast cancer.

The impact of treatment compliance on fracture risk in women with breast cancer treated with aromatase inhibitors in the United Kingdom

No study has yet analyzed the impact of compliance with aromatase inhibitor(AI) treatments on fracture risk in a real-world setting in women with breast cancer. In this study, 8732 women with BC treated with AI, 8732 treated with tamoxifen (TAM), and 8732 age-matched women without BC selected from the Disease Analyzer database (IMS Health) were included. The main outcome measure was the impact of compliance with AI treatment on fracture risk. Demographic data included age, body mass index (BMI), and smoking status. Alcohol dependency, dementia, bone density, visual disturbances, diabetes, and use of corticosteroids were also assessed. Kaplan-Meier curves were used to analyze the proportion of patients with fracture over time, and multivariate Cox regression models were performed to assess the adjusted fracture risk. Mean age was 67.3 years. 17.6, 8.7, and 8.8 % of AI, TAM, and non-cancer patients, respectively, were diagnosed with fracture within 5 years after the index date (p < 0.001). The proportion of women receiving AI with fracture increased with treatment compliance, rising from 8.6 % when treatment persisted for less than a year to 18.0 % when it persisted for between 4 and 5 years (p < 0.001). By contrast, the proportion of fractures in women with BC receiving TAM for the same time periods decreased from 13.0 to 7.9 % (p < 0.001). The risk of fracture was higher in women with BC using AI than in the non-cancer group (HR = 3.00; p < 0.0001). Finally, current smoking status, BMI, dementia, and prescription of corticosteroids had significant impacts on fracture risk. Compliance with AI treatment in women with BC is associated with a clear increase in the risk of fracture, which is much higher than previously reported.

Adjuvant bisphosphonates in early breast cancer: consensus guidance for clinical practice from a European Panel

Bisphosphonates have been studied in randomised trials in early breast cancer to investigate their ability to prevent cancer treatment-induced bone loss (CTIBL) and reduce the risk of disease recurrence and metastasis. Treatment benefits have been reported but bisphosphonates do not currently have regulatory approval for either of these potential indications. This consensus paper provides a review of the evidence and offers guidance to breast cancer clinicians on the use of bisphosphonates in early breast cancer. Using the nominal group methodology for consensus, a systematic review of the literature was augmented by a workshop held in October 2014 for breast cancer and bone specialists to present and debate the available pre-clinical and clinical evidence for the use of adjuvant bisphosphonates. This was followed by a questionnaire to all members of the writing committee to identify areas of consensus. The panel recommended that bisphosphonates should be considered as part of routine clinical practice for the prevention of CTIBL in all patients with a T score of <-2.0 or ≥2 clinical risk factors for fracture. Compelling evidence from a meta-analysis of trial data of >18,000 patients supports clinically significant benefits of bisphosphonates on the development of bone metastases and breast cancer mortality in post-menopausal women or those receiving ovarian suppression therapy. Therefore, the panel recommends that bisphosphonates (either intravenous zoledronic acid or oral clodronate) are considered as part of the adjuvant breast cancer treatment in this population and the potential benefits and risks discussed with relevant patients.

Endocrine resistance in breast cancer--An overview and update

Tumors that express detectable levels of the product of the ESR1 gene (estrogen receptor-α; ERα) represent the single largest molecular subtype of breast cancer. More women eventually die from ERα+ breast cancer than from either HER2+ disease (almost half of which also express ERα) and/or from triple negative breast cancer (ERα-negative, progesterone receptor-negative, and HER2-negative). Antiestrogens and aromatase inhibitors are largely indistinguishable from each other in their abilities to improve overall survival and almost 50% of ERα+ breast cancers will eventually fail one or more of these endocrine interventions. The precise reasons why these therapies fail in ERα+ breast cancer remain largely unknown. Pharmacogenetic explanations for Tamoxifen resistance are controversial. The role of ERα mutations in endocrine resistance remains unclear. Targeting the growth factors and oncogenes most strongly correlated with endocrine resistance has proven mostly disappointing in their abilities to improve overall survival substantially, particularly in the metastatic setting. Nonetheless, there are new concepts in endocrine resistance that integrate molecular signaling, cellular metabolism, and stress responses including endoplasmic reticulum stress and the unfolded protein response (UPR) that provide novel insights and suggest innovative therapeutic targets. Encouraging evidence that drug combinations with CDK4/CDK6 inhibitors can extend recurrence free survival may yet translate to improvements in overall survival. Whether the improvements seen with immunotherapy in other cancers can be achieved in breast cancer remains to be determined, particularly for ERα+ breast cancers. This review explores the basic mechanisms of resistance to endocrine therapies, concluding with some new insights from systems biology approaches further implicating autophagy and the UPR in detail, and a brief discussion of exciting new avenues and future prospects.

The molecular, cellular and clinical consequences of targeting the estrogen receptor following estrogen deprivation therapy

During the past 20 years our understanding of the control of breast tumor development, growth and survival has changed dramatically. The once long forgotten application of high dose synthetic estrogen therapy as the first chemical therapy to treat any cancer has been resurrected, refined and reinvented as the new biology of estrogen-induced apoptosis. High dose estrogen therapy was cast aside once tamoxifen, from its origins as a failed "morning after pill", was reinvented as the first targeted therapy to treat any cancer. The current understanding of the mechanism of estrogen-induced apoptosis is described as a consequence of acquired resistance to long term antihormone therapy in estrogen receptor (ER) positive breast cancer. The ER signal transduction pathway remains a target for therapy in breast cancer despite "antiestrogen" resistance, but becomes a regulator of resistance. Multiple mechanisms of resistance come into play: Selective ER modulator (SERM) stimulated growth, growth factor/ER crosstalk, estrogen-induced apoptosis and mutations of ER. But it is with the science of estrogen-induced apoptosis that the next innovation in women's health will be developed. Recent evidence suggests that the glucocorticoid properties of medroxyprogesterone acetate blunt estrogen-induced apoptosis in estrogen deprived breast cancer cell populations. As a result breast cancer develops during long-term hormone replacement therapy (HRT). A new synthetic progestin with estrogen-like properties, such as the 19 nortestosterone derivatives used in oral contraceptives, will continue to protect the uterus from unopposed estrogen stimulation but at the same time, reinforce apoptosis in vulnerable populations of nascent breast cancer cells.

Contribution of ABCB1 and CYP2D6 Genotypes to the Outcome of Tamoxifen Adjuvant Treatment in Premenopausal Women With Breast Cancer

Recent pre-clinical evidence suggests that the active metabolite of tamoxifen, endoxifen, is a substrate for efflux pump P-glycoprotein. The aim of our study was to evaluate, if the polymoprhisms within ABCB1 gene alter tamoxifen adjuvant treatment efficacy in premenopausal women. Totally 71 premenopausal women with estrogen receptor positive breast cancer indicated for tamoxifen adjuvant treatment were followed retrospectively for median period of 56 months. The gentic polymorphisms of CYP2D6 and ABCB1 were analyzed and potential covariates as tumor grading, staging, age at the diagnosis, comedication, quantitative positivity of ER or PR were also evaluated. Cox proportional-hazards regression model indicated that patients carrying at least one variant allele in ABCB1 rs1045642 had significantly longer time to event survival compared to wild type subjects. Non-significant trend was noted for better treatment outcome of patients carrying at least one variant allele in the SNP rs2032582, while for the CYP2D6 polymorphism poor metabolizer phenotype resulted in worse outcome in comparison to extensive metabolizers subjects with HR of 4.04 (95 % CI 0.31-52.19). Similarly, patients using CYP2D6 inhibitors had non-significantly shorter time-to-event as compared to never users resulting in hazard ratio of 2.06 (95 % CI 0.40-10.63). ABCB1 polymorphisms may affect outcome of tamoxifen adjuvant treatment in premenopausal breast cancer patiens. This factor should be taken into account in addition to the CYP2D6 polymorphism or phenotypic inhibition of CYP2D6 activity.

Support not corresponding to transition to a new treatment: Women's perceptions of support provided by their male partners during hormonal therapy

Women with breast cancer receive support from their partners to deal with the side effects of therapies over the cancer trajectory. Hormonal therapy (HT) is usually given after completing other treatments, and women receiving HT reclaim their normal life. This may lead to changes in support from their partners. Therefore, we explored women's perceptions of the support provided by their male partners in managing the side effects of adjuvant HT. We conducted semi-structured interviews with 10 women who received HT and recognized their partners as a main source of support. An interview guide was used to explore their experiences of treatment side effects, the contents of support received from their partners, their need for support, and their overall relationship with their partners. Interviews were analysed by content analysis. A theme on how participants perceived support from their partners was formulated as “Support not corresponding to transition to a new treatment” with the following categories: “Shrinking support,” “Primacy of partner,” and “Solitary new treatment.” Participants felt lack of support from their partners because their partners did not understand their experience of the side effects induced by HT. Unlike the side effects of past treatments such as surgery and chemotherapy, side effects of HT cannot be observed and are highly subjective. Their partners often failed to notice these symptoms and provided little support. Nevertheless, participants aimed to accept the existing support without asking for more. They were left alone in the continuing trajectory of breast cancer. After starting HT, women entered a new treatment phase in which less understanding and support was provided by partners. Educational support for couples may enable sharing of subjective symptoms that are not obvious to partners and improve outcomes by facilitating partner engagement and support.

Statistical controversies in clinical research: long-term follow-up of clinical trials in cancer

Long-term follow-up is an important unmet need for the full analysis of new treatments for cancer. Earlier detection of cancer and more effective treatment have led to many more patients surviving for more than 5 and even 10 years, so that evaluating late recurrences and side-effects is an increasingly important issue. This is particularly relevant for oestrogen receptor-positive breast cancer, where the existence of late recurrences is well documented. However, survival for other cancers, notably prostate, colorectal and cervix cancer, has dramatically increased in recent years due to screening and better treatment of early lesions. Trials of preventive therapies have an even greater need for long follow-up. Here, we review these issues and suggest ways in which provision for long-term follow-up can be improved.

Proposing Essential Medicines to Treat Cancer: Methodologies, Processes, and Outcomes

PURPOSE

A great proportion of the world's cancer burden resides in low- and middle-income countries where cancer care infrastructure is often weak or absent. Although treatment of cancer is multidisciplinary, involving surgery, radiation, systemic therapies, pathology, radiology, and other specialties, selection of medicines that have impact and are affordable has been particularly challenging in resource-constrained settings. In 2014, at the invitation of the WHO, the Union for International Cancer Control convened experts to develop an approach to propose essential cancer medicines to be included in the WHO Model Essential Medicines Lists (EML) for Adults and for Children, as well as a resulting new list of cancer medicines.

METHODS

Experts identified 29 cancer types with potential for maximal treatment impact, on the basis of incidence and benefit of systemic therapies. More than 90 oncology experts from all continents drafted and reviewed disease-based documents outlining epidemiology, diagnostic needs, treatment options, and benefits and toxicities.

RESULTS

Briefing documents were created for each disease, along with associated standard treatment regimens, resulting in a list of 52 cancer medicines. A comprehensive application was submitted as a revision to the existing cancer medicines on the WHO Model Lists. In May 2015, the WHO announced the addition of 16 medicines to the Adult EML and nine medicines to the Children's EML.

CONCLUSION

The list of medications proposed, and the ability to link each recommended medicine to specific diseases, should allow public officials to apply resources most effectively in developing and supporting nascent or growing cancer treatment programs.

Prospective assessment of the decision-making impact of the Breast Cancer Index in recommending extended adjuvant endocrine therapy for patients with early-stage ER-positive breast cancer

Extended adjuvant endocrine therapy (10 vs. 5 years) trials have demonstrated improved outcomes in early-stage estrogen receptor (ER)-positive breast cancer; however, the absolute benefit is modest, and toxicity and tolerability challenges remain. Predictive and prognostic information from genomic analysis may help inform this clinical decision. The purpose of this study was to assess the impact of the Breast Cancer Index (BCI) on physician recommendations for extended endocrine therapy and on patient anxiety and decision conflict. Patients with stage I–III, ER-positive breast cancer who completed at least 3.5 years of adjuvant endocrine therapy were offered participation. Genomic classification with BCI was performed on archived tumor tissues and the results were reported to the treating physician who discussed results with the patient. Patients and physicians completed pre- and post-test questionnaires regarding preferences for extended endocrine therapy. Patients also completed the validated traditional Decisional Conflict Scale (DCS) and State Trait Anxiety Inventory forms (STAI-Y1) pre- and post-test. 96 patients were enrolled at the Yale Cancer Center [median age 60.5 years (range 45–87), 79 % postmenopausal, 60 % stage I). BCI predicted a low risk of late recurrence in 59 % of patients versus intermediate/high in 24 and 17 %, respectively. Physician recommendations for extended endocrine therapy changed for 26 % of patients after considering BCI results, with a net decrease in recommendations for extended endocrine therapy from 74 to 54 %. After testing, fewer patients wanted to continue extended therapy and decision conflict and anxiety also decreased. Mean STAI and DCS scores were 31.3 versus 29.1 (p = 0.031) and 20.9 versus 10.8 (p < 0.001) pre- and post-test, respectively. Incorporation of BCI into risk/benefit discussions regarding extended endocrine therapy resulted in changes in treatment recommendations and improved patient satisfaction.

Fulvestrant 500 mg Versus Anastrozole 1 mg for the First-Line Treatment of Advanced Breast Cancer: Overall Survival Analysis From the Phase II FIRST Study

PURPOSE

To compare overall survival (OS) for fulvestrant 500 mg versus anastrozole as first-line endocrine therapy for advanced breast cancer.

PATIENTS AND METHODS

The Fulvestrant First-Line Study Comparing Endocrine Treatments (FIRST) was a phase II, randomized, open-label, multicenter trial. Postmenopausal women with estrogen receptor-positive, locally advanced/metastatic breast cancer who had no previous therapy for advanced disease received either fulvestrant 500 mg (days 0, 14, 28, and every 28 days thereafter) or anastrozole 1 mg (daily). The primary end point (clinical benefit rate [72.5% and 67.0%]) and a follow-up analysis (median time to progression [23.4 months and 13.1 months]) have been reported previously for fulvestrant 500 mg and anastrozole, respectively. Subsequently, the protocol was amended to assess OS by unadjusted log-rank test after approximately 65% of patients had died. Treatment effect on OS across several subgroups was examined. Tolerability was evaluated by adverse event monitoring.

RESULTS

In total, 205 patients were randomly assigned (fulvestrant 500 mg, n = 102; anastrozole, n = 103). At data cutoff, 61.8% (fulvestrant 500 mg, n = 63) and 71.8% (anastrozole, n = 74) had died. The hazard ratio (95% CI) for OS with fulvestrant 500 mg versus anastrozole was 0.70 (0.50 to 0.98; P = .04; median OS, 54.1 months v 48.4 months). Treatment effects seemed generally consistent across the subgroups analyzed. No new safety issues were observed.

CONCLUSION

There are several limitations of this OS analysis, including that it was not planned in the original protocol but instead was added after time-to-progression results were analyzed, and that not all patients participated in additional OS follow-up. However, the present results suggest fulvestrant 500 mg extends OS versus anastrozole. This finding now awaits prospective confirmation in the larger phase III FALCON (Fulvestrant and Anastrozole Compared in Hormonal Therapy Naïve Advanced Breast Cancer) trial (ClinicalTrials.gov identifier: NCT01602380).

Analysis of factors affecting endocrine therapy resistance in breast cancer

The present study aimed to identify the factors involved in the resistance to endocrine therapy in breast cancer (BC) patients with a positive estrogen receptor status via the collection of clinical, pathological and immunohistochemical indices. A retrospective survey was performed in patients who experienced the relapse and metastasis of BC between November 2007 and March 2013. A total of 45 patients were enrolled, and the observational duration was 7-84 months. The Kaplan-Meier method was used to create a survival curve, while the log-rank test was used to analyze the survival curve and the Cox regression analysis was used to investigate the associated factors contributing to the resistance to endocrine therapy. Univariate analysis showed that the age of onset, the use of radiotherapy, the endocrine treatment program, and the expression levels of progesterone receptor (PR) and CerbB2 affected the impact of endocrine treatment. The Cox regression analysis indicated that the age of onset, the use of radiotherapy, and the expression levels of PR and CerbB2 affected the disease-free survival time after endocrine therapy. A young age of onset, not receiving radiotherapy, a low expression level of PR and a high expression level of CerbB2 were the risk factors involved in the resistance to endocrine therapy in patients with BC.

Associations between genetic variants and the effect of letrozole and exemestane on bone mass and bone turnover

Adjuvant therapy for hormone receptor (HR) positive postmenopausal breast cancer patients includes aromatase inhibitors (AI). While both the non-steroidal AI letrozole and the steroidal AI exemestane decrease serum estrogen concentrations, there is evidence that exemestane may be less detrimental to bone. We hypothesized that single nucleotide polymorphisms (SNP) predict effects of AIs on bone turnover. Early stage HR-positive breast cancer patients were enrolled in a randomized trial of exemestane versus letrozole. Effects of AI on bone mineral density (BMD) and bone turnover markers (BTM), and associations between SNPs in 24 candidate genes and changes in BMD or BTM were determined. Of the 503 enrolled patients, paired BMD data were available for 123 and 101 patients treated with letrozole and exemestane, respectively, and paired BTM data were available for 175 and 173 patients, respectively. The mean change in lumbar spine BMD was significantly greater for letrozole-treated (-3.2 %) compared to exemestane-treated patients (-1.0 %) (p = 0.0016). Urine N-telopeptide was significantly increased in patients treated with exemestane (p = 0.001) but not letrozole. Two SNPs (rs4870061 and rs9322335) in ESR1 and one SNP (rs10140457) in ESR2 were associated with decreased BMD in letrozole-treated patients. In the exemestane-treated patients, SNPs in ESR1 (Rs2813543) and CYP19A1 (Rs6493497) were associated with decreased bone density. Exemestane had a less negative impact on bone density compared to letrozole, and the effects of AI therapy on bone may be impacted by genetic variants in the ER pathway.

Assessment of Breast Cancer Patients' Knowledge and Decisional Conflict Regarding Tamoxifen Use

Breast cancer is the most common type of female cancer. Tamoxifen, a selective estrogen receptor modulator, is widely used to decrease breast cancer recurrence and mortality among patients. However, it also increases the risk of endometrial cancer. This study aimed to assess knowledge and decisional conflict regarding tamoxifen use. Between June and October 2014, breast cancer patients using tamoxifen were consecutively screened and requested to complete a survey including the EQ-5D, Satisfaction with Decision Scale (SWD), Decisional Conflict Scale (DCS), and a self-developed, 15-item questionnaire measuring tamoxifen-related knowledge. The study sample comprised 299 patients. The mean total knowledge score was 63.4 of a possible 100.0 (range, 13.3-93.3). While 73.9% of the participants knew that tamoxifen reduces the risk of breast cancer recurrence, only 57.9% knew that the drug increases endometrial cancer risk. A higher education level (≥ college) was associated with a higher, total knowledge score (β = 4.291; P = 0.017). A higher knowledge score was associated with a decreased DCS score (β = -0.366; P < 0.001). A higher SWD score was also associated with decreased decisional conflict (β = -0.178; P < 0.001). In conclusion, the breast cancer patients with higher levels of tamoxifen-related knowledge showed lower levels of decisional conflict regarding tamoxifen use. Clinicians should provide the exact information about tamoxifen treatment to patients, based on knowledge assessment results, so as to aid patients' decision-making with minimal conflict.

Breast cancer recurrence in relation to antidepressant use

PURPOSE

Women with breast cancer frequently use antidepressants; however, questions about the effect of these medications on breast cancer recurrence remain.

METHODS

We identified 4,216 women ≥18 years with an incident stage I or II breast cancer diagnosed between 1990 and 2008 in a mixed-model healthcare delivery system linked to a cancer registry. Recurrences were ascertained from chart review. Medication exposures were extracted from electronic pharmacy records. We used multivariable Cox proportional hazards models to estimate hazard ratios (HR) and 95 % confidence intervals (CI) to assess the association between antidepressant use and breast cancer recurrence and mortality. We also conducted analyses restricted to tamoxifen users.

RESULTS

Antidepressants overall, tricyclic antidepressants, and selective serotonin reuptake inhibitors were not associated with risk of breast cancer recurrence or mortality. Women taking paroxetine only (adjusted HR: 1.66; 95 % CI 1.02, 2.71) and trazodone only (adjusted HR: 1.76; 95 % CI 1.06, 2.92), but not fluoxetine only (adjusted HR: 0.92; 95 % CI 0.55, 1.53), had higher recurrence risks than antidepressant nonusers. There was some suggestion of an increased recurrence risk with concurrent paroxetine and tamoxifen use compared with users of tamoxifen only (adjusted HR: 1.49; 95 % CI 0.79, 2.83).

CONCLUSIONS

In general, antidepressants did not appear increase risk of breast cancer recurrence, though there were some suggested increases in risk that warrant further investigation in other datasets. Our results combined systematically and quantitatively with results from other studies may be useful for patients and providers making decisions about antidepressant use after breast cancer diagnosis.

Time-Varying Effects of Breast Cancer Adjuvant Systemic Therapy

BACKGROUND

The benefits of breast cancer adjuvant systemic treatments are generally assumed to be proportional (or constant) over time, but limited data suggest that some treatment effects may vary with time. We therefore systematically assessed the proportional hazards assumption across all 19 breast cancer adjuvant systemic therapy trials in the National Surgical Adjuvant Breast and Bowel Project (NSABP) database.

METHODS

The NSABP breast cancer trials were tested for the proportionality of hazard rates between randomized treatment groups for five endpoints: overall survival, disease-free survival and recurrence, local-regional recurrence, or distant recurrence as first events. When the proportional hazards assumption did not hold, a "change point for the relative risk" technique was used to identify the temporal breakdown of the treatment effect.

RESULTS

Time-varying treatment effects were observed in nearly half of the trials (nine of 19). In six (B-05, B-11, B-12, B-14, B-16, and B-20), novel treatment benefits diminished statistically significantly at specific time points following surgery. In B-09 and B-31, novel treatment benefits were delayed and emerged more than one year after surgery (1.57 and 1.32 years correspondingly), but the benefit in B-09 reversed after the third year of follow-up. In one trial (B-23), the initial advantage and subsequent disadvantage of one of the regimens was evident.

CONCLUSIONS

Breast cancer adjuvant systemic therapy can have statistically significant time-varying effects, which should be considered in the design, analysis, reporting, and translation of clinical trials. These time-dependent effects will have greater relevance as the number of long-term breast cancer survivors increases.

Adjuvant Endocrine Therapy and Bone Health in Breast Cancer

Breast cancer is one of the most common malignancies of women. The majority of breast cancers express estrogen and/or progesterone receptors, permitting anticancer targeting strategies to reduce estrogen signaling in the cancer cells and thereby lowering the risk of breast cancer recurrence. The development of the selective estrogen receptor modulator (SERM) tamoxifen marked a significant milestone in breast cancer care that transcended older estrogen ablative strategies such as oophorectomy and ovarian irradiation. An unintended benefit of tamoxifen in postmenopausal women was bone density preservation. The third generation of aromatase inhibitors (AIs) have demonstrated superior efficacy to tamoxifen in improving disease-free survival in postmenopausal women. However, the AIs significantly increase bone resorption, reduce bone mineral density, and increase the risk of fracture above that of tamoxifen. As a consequence of this, clinical oncologists have assumed a larger role in the screening and treatment of the skeletal complications of breast cancer therapies. The key features of managing bone health in women with early stage breast cancer receiving adjuvant endocrine therapy are reviewed here.

Adjuvant endocrine therapy in premenopausal women with breast cancer

Breast cancer remains the leading cause of cancer-related mortality in premenopausal women. Multiple advances in local and systemic therapies have dramatically improved outcomes in women with hormone receptor-positive early-stage breast cancer. Despite these advances, early and late relapses occur. Therefore, multiple adjuvant endocrine therapy trials have been conducted with the goal of decreasing breast cancer recurrence and mortality. Recently, large international trials evaluating extended endocrine therapy and ovarian suppression with and without tamoxifen or exemestane have been reported. These studies add to the large body of existing data on adjuvant endocrine therapy in premenopausal women with breast cancer and provide additional therapeutic options in those at high risk of disease recurrence. This review will synthesize the most recent data and promote an evidence-based approach, highlighting quality-of-life concerns, to considering adjuvant endocrine therapies in premenopausal women.

Phase 3, open-label, randomized study comparing 3-monthly with monthly goserelin in pre-menopausal women with estrogen receptor-positive advanced breast cancer

BACKGROUND

Monthly goserelin 3.6 mg dosing suppresses estradiol (E2) production and has proven efficacy in pre-menopausal women with estrogen receptor (ER)-positive breast cancer. This non-inferiority study evaluated the efficacy and safety of 3-monthly goserelin 10.8 mg compared with monthly goserelin 3.6 mg.

METHODS

This was a Phase 3, open-label, multicenter trial. Pre-menopausal women with ER-positive advanced breast cancer were randomized to 3-monthly goserelin 10.8 mg or monthly goserelin 3.6 mg; all patients received concomitant tamoxifen (20 mg daily). The primary endpoint was progression-free survival (PFS) rate at 24 weeks; non-inferiority was to be confirmed if the entire 95 % confidence interval (CI) for the treatment difference was above -17.5 %. Secondary endpoints included objective response rate (ORR), serum E2 levels, safety, and tolerability.

RESULTS

In total, 222 patients were randomized (goserelin 10.8 mg, n = 109; goserelin 3.6 mg, n = 113). PFS rate at week 24 was 61.5 % (goserelin 10.8 mg) and 60.2 % (goserelin 3.6 mg); treatment difference (95 % CI) was 1.3 % (-11.4, 13.9), confirming non-inferiority of goserelin 10.8 mg compared with goserelin 3.6 mg. ORR was 23.9 % (goserelin 10.8 mg) and 26.9 % (goserelin 3.6 mg); treatment difference (95 % CI) was -3.0 % (-15.5, 9.7). At week 24, mean serum E2 concentrations were similar in the goserelin 10.8 mg and goserelin 3.6 mg groups (20.3 pg/mL and 24.8 pg/mL, respectively).

CONCLUSION

A regimen of 3-monthly goserelin 10.8 mg demonstrated non-inferiority compared with monthly goserelin 3.6 mg for PFS rate at 24 weeks, with similar pharmacodynamic and safety profiles, in pre-menopausal women with ER-positive breast cancer.

Phosphoproteomic Analysis Identifies Focal Adhesion Kinase 2 (FAK2) as a Potential Therapeutic Target for Tamoxifen Resistance in Breast Cancer

Tamoxifen, an estrogen receptor-α (ER) antagonist, is an important agent for the treatment of breast cancer. However, this therapy is complicated by the fact that a substantial number of patients exhibit either de novo or acquired resistance. To characterize the signaling mechanisms underlying this resistance, we treated the MCF7 breast cancer cell line with tamoxifen for over six months and showed that this cell line acquired resistance to tamoxifen in vitro and in vivo. We performed SILAC-based quantitative phosphoproteomic profiling on the tamoxifen resistant and vehicle-treated sensitive cell lines to quantify the phosphorylation alterations associated with tamoxifen resistance. From >5600 unique phosphopeptides identified, 1529 peptides exhibited hyperphosphorylation and 409 peptides showed hypophosphorylation in the tamoxifen resistant cells. Gene set enrichment analysis revealed that focal adhesion pathway was one of the most enriched signaling pathways activated in tamoxifen resistant cells. Significantly, we showed that the focal adhesion kinase FAK2 was not only hyperphosphorylated but also transcriptionally up-regulated in tamoxifen resistant cells. FAK2 suppression by specific siRNA knockdown or a small molecule inhibitor repressed cellular proliferation in vitro and tumor formation in vivo. More importantly, our survival analysis revealed that high expression of FAK2 is significantly associated with shorter metastasis-free survival in estrogen receptor-positive breast cancer patients treated with tamoxifen. Our studies suggest that FAK2 is a potential therapeutic target for the management of hormone-refractory breast cancers.

Current medical treatment of estrogen receptor-positive breast cancer

Approximately 80% of breast cancers (BC) are estrogen receptor (ER)-positive and thus endocrine therapy (ET) should be considered complementary to surgery in the majority of patients. The advantages of oophorectomy, adrenalectomy and hypophysectomy in women with advanced BC have been demonstrated many years ago, and currently ET consist of (1) ovarian function suppression (OFS), usually obtained using gonadotropin-releasing hormone agonists (GnRHa); (2) selective estrogen receptor modulators or down-regulators (SERMs or SERDs); and (3) aromatase inhibitors (AIs), or a combination of two or more drugs. For patients aged less than 50 years and ER+ BC, there is no conclusive evidence that the combination of OFS and SERMs (i.e., tamoxifen) or chemotherapy is superior to OFS alone. Tamoxifen users exhibit a reduced risk of BC, both invasive and in situ, especially during the first 5 years of therapy, and extending the treatment to 10 years further reduced the risk of recurrences. SERDs (i.e., fulvestrant) are especially useful in the neoadjuvant treatment of advanced BC, alone or in combination with either cytotoxic agents or AIs. There are two types of AIs: type I are permanent steroidal inhibitors of aromatase, while type II are reversible nonsteroidal inhibitors. Several studies demonstrated the superiority of the third-generation AIs (i.e., anastrozole and letrozole) compared with tamoxifen, and adjuvant therapy with AIs reduces the recurrence risk especially in patients with advanced BC. Unfortunately, some cancers are or became ET-resistant, and thus other drugs have been suggested in combination with SERMs or AIs, including cyclin-dependent kinase 4/6 inhibitors (palbociclib) and mammalian target of rapamycin (mTOR) inhibitors, such as everolimus. Further studies are required to confirm their real usefulness.

Crosstalk events in the estrogen signaling pathway may affect tamoxifen efficacy in breast cancer molecular subtypes

Steroid hormones are involved on cell growth, development and differentiation. Such effects are often mediated by steroid receptors. One paradigmatic example of this coupling is the estrogen signaling pathway. Its dysregulation is involved in most tumors of the mammary gland. It is thus an important pharmacological target in breast cancer. This pathway, however, crosstalks with several other molecular pathways, a fact that may have consequences for the effectiveness of hormone modulating drug therapies, such as tamoxifen. For this work, we performed a systematic analysis of the major routes involved in crosstalk phenomena with the estrogen pathway - based on gene expression experiments (819 samples) and pathway analysis (493 samples) - for biopsy-captured tissue and contrasted in two independent datasets with in vivo and in vitro pharmacological stimulation. Our results confirm the presence of a number of crosstalk events across the estrogen signaling pathway with others that are dysregulated in different molecular subtypes of breast cancer. These may be involved in proliferation, invasiveness and apoptosis-evasion in patients. The results presented may open the way to new designs of adjuvant and neoadjuvant therapies for breast cancer treatment.

Selective estrogen receptor modulators and the combination therapy conjugated estrogens/bazedoxifene: A review of effects on the breast

Traditional menopausal hormone therapy containing estrogens/progestin has been associated with an increased risk of breast cancer, and estrogen exposure is known to promote growth and proliferation of a majority of breast cancers. Therefore, it is important for clinicians to consider the breast safety profile of any hormone-based therapy used in postmenopausal women. This review provides an overview of the breast safety and tolerability profiles of currently marketed selective estrogen receptor modulators, antiestrogens, and the first tissue selective estrogen complex combining conjugated estrogens with the selective estrogen receptor modulator bazedoxifene in postmenopausal women. Selective estrogen receptor modulators and antiestrogens act as estrogen receptor antagonists in the breast. Tamoxifen, toremifene, and the selective estrogen receptor degrader fulvestrant are used to treat breast cancer, and tamoxifen and raloxifene protect against breast cancer in high-risk women. Postmenopausal women using selective estrogen receptor modulators for prevention or treatment of osteoporosis (raloxifene, bazedoxifene) can be reassured that these hormonal treatments do not adversely affect their risk of breast cancer and may, in the case of raloxifene, even be protective. There are limited data on breast cancer in women who use ospemifene for dyspareunia. Conjugated estrogens/bazedoxifene use for up to two years did not increase mammographic breast density or breast pain/tenderness, and there was no evidence of an increased risk of breast cancer, suggesting that conjugated estrogens/bazedoxifene has an improved breast safety profile compared with traditional menopausal hormone therapies. Future research will continue to focus on development of selective estrogen receptor modulators and selective estrogen receptor modulator combinations capable of achieving the ideal balance of estrogen receptor agonist and antagonist effects.

Tamoxifen-induced ovarian hyperstimulation during premenopausal hormonal therapy for breast cancer in Japanese women

Purpose

Tamoxifen is an anti-estrogenic drug that is widely used for endocrine-dependent breast cancer as adjuvant hormonal therapy, and its use has been reported to be frequently associated with high levels of serum estradiol. Since the population of premenopausal women receiving tamoxifen therapy is growing in Japan, we retrospectively analyzed the incidence of ovarian hyperstimulation by tamoxifen therapy in Japanese women.

Methods

Eleven patients who received surgical therapy for endocrine-dependent breast cancer and showed high values of serum estradiol during post-operative tamoxifen therapy were recruited in this study and evaluated by examining the serum concentration of follicular stimulating hormone (FSH) and follicular development.

Results

The mean age, serum concentrations of estradiol and FSH, and follicular diameter were 41.3 years old, 1015.8 pg/mL, 11.8 mIU/mL, and 3.47 cm, respectively. In 6 cases, multiple follicular development was observed, while the other cases showed single follicular development with a mean serum estradiol level of 848.6 pg/mL and follicular diameter of 4.46 cm. There was no significant difference in age or FSH concentration between the two groups. The mean periods from the start of the single administration of tamoxifen to the initial detection of a high estradiol concentration was 716.5 days.

Conclusions

These findings indicate that tamoxifen could stimulate the ovarian function even after 2-year treatment. Since single and multiple follicular developments with large sizes were observed, dual mechanisms through the inhibition of both negative and positive feedback to the hypothalamic-pituitary-axis can be proposed to explain the adverse effects of tamoxifen on ovarian function.

Hypomethylation of DNA-binding inhibitor 4 serves as a potential biomarker in distinguishing acquired tamoxifen-refractory breast cancer

OBJECTIVE

To explore the methylation status of DNA-binding inhibitor 4 (ID4) in tamoxifen-refractory (TR) breast cancer.

METHODS

From January 2012 to December 2014, breast cancer patients managed by radical mastectomy previously and receiving tamoxifen treatment for at least 12 months were enrolled. According to the response to tamoxifen, patients were divided into TR group and tamoxifen-sensitive (TS) group. Genomic DNA was isolated from fasting venous blood, and methylight technique was applied to determine the methylation status of ID4.

RESULTS

43 patients with TS breast cancer and 31 patients with TR breast cancer were enrolled. No significant difference between groups was observed in term of patients' characteristics, such as age (P=0.693), progesterone receptor (P=0.970), menopausal status (P=0.784) and histological type (P=0.537), while the stage of cancer in TR group was significantly higher than TS group (P<0.001). Compared to TS group, PMR of ID4 was significantly higher in TR group (P=0.002). ROC curve analysis indicated that ID4 yielded an AUC of 0.716 with 77.4% sensitivity and 62.79% specificity in distinguishing TR breast cancer at the cut point of 3.8%. The PMR cut point of ID4 was set at 6.8% in survival analysis, log-rank test indicated the risk of disease progression was comparable between patients with ID4 hypermethylation or hypomethylation (P=0.287).

CONCLUSION

ID4 hypomethylation is present in TR breast cancer, and it may serve as a potential biomarker in distinguishing TR breast cancer. However, the results need further validation in larger studies.

Clinical utility of genetic signatures in selecting adjuvant treatment: Risk stratification for early vs. late recurrences

Adjuvant endocrine therapy (ET) reduces the odds of distant recurrence and mortality by nearly one-half in women with hormone receptor (HR) positive early stage breast cancer. While the risk of recurrence is lower for HR positive than negative patients during the first 5-7 years, HR positive patients suffer ongoing recurrences between 0.5 and 2% year over subsequent years. Extended adjuvant ET further reduces recurrence during this late phase of follow-up. ET is associated with post-menopausal side effects (hot flashes, sexual dysfunction, mood changes, and weight gain), and occasional major toxicities (thrombosis and endometrial cancer with tamoxifen; bone mineral loss and possibly heart disease with AIs) persist throughout therapy. Accurate and reliable estimates of the risk of recurrence after five years of ET for women with prior HR positive breast cancer would permit appropriate extended ET decisions. The risk of long-term relapse is related to lymph node status and size of tumor, but these are relatively crude. Several groups have investigated whether multi-parameter tumor biomarker tests might identify those patients whose risk of recurrence is so low that extended ET is not justified. These assays include IHC4, the 21-gene "OncotypeDX", the 12-gene "Endopredict," the PAM50, and the 2-gene "Breast Cancer Index (BCI)" assays. The clinical validity of all these tests for this use context have been established, with at least one paper for each that shows a statistically significant difference in risk of distant recurrence during the 5-10 years after the initial five years of adjuvant endocrine therapy. However, the stakes are high, and although each of these represents a "prospective retrospective" study, they require further validation in subsequent datasets before they should be considered to have "clinical utility" and are used to withhold potentially life-saving treatment. Perhaps more importantly, the clinical breast cancer community, and especially the patient, need to determine how low the risk of late recurrence needs to be to forego the toxicities and side effects of extended adjuvant ET.