Novel therapeutics in breast cancer—Looking to the future

Breast cancer treatment has evolved dramatically in the last few years. Despite the benefit of anthracyclines, taxanes and trastuzumab for patients with metastatic and early breast cancer, the challenges of de novo and acquired resistance are still present. With advances in the molecular characterization of breast cancer, patient selection and individualization of treatment has taken on singular importance. Three main types of breast cancer have been reported to date: (a) HER-2 positive; (b) basal-like; and (c) luminal breast cancer. A large number of new agents now target different receptors and signalling pathways that sustain cancer survival and proliferation. In this review we highlight the novel molecules currently being tested in clinical trials that have or will have the potential to change our daily clinical practice; in particular, we focus on molecules used in the treatment of HER-2 positive and basal-like breast cancer patients.     

HDAC抑制剂调控乳腺癌细胞HER-2表达的研究进展北大核心

乳腺癌是女性最常见的恶性肿瘤,约15%~20%的患者呈HER-2过表达,该亚型患者易复发转移,预后较差。HER-2过表达不仅与基因扩增有关,还受表观调控的影响。组蛋白去乙酰化酶抑制剂被认为是靶向癌细胞表观基因组的代表性药物,在HER-2阳性乳腺癌中,组蛋白去乙酰化酶抑制剂可通过下调HER-2表达,与靶向HER-2的大分子单抗表现出协同作用。本文我们将重点概述组蛋白去乙酰化酶抑制剂下调HER-2表达的机制以及在乳腺癌治疗中的研究现状。     

Her-2/neu as a Predictive Marker of Response to Breast Cancer Therapy

Amplification of the HER-2/neu (c-erbB-2) gene resulting in overexpression of the p185HER-2 growth factor receptor occurs in ~25% of early stage breast cancers. HER- 2/neu has been established as an important independent prognostic factor in early stage breast cancer in large cohorts of patients and in cohorts with very long (30 year) follow-up duration. New data are emerging to suggest that HER-2/neu may be useful not only as a prognostic factor but also as a predictive marker for projecting response to chemotherapeutics, antiestrogens, and therapeutic anti-HER- 2/neu monoclonal antibodies. In this review we highlight recent data on HER-2/neu as a predictive marker of response to breast cancer therapy and discuss the clinical implications of this information. The difficulty in comparing results from different data sets due to the wide variety of reagents and technologies used to detect HER-2/neu amplification/overexpression in clinical specimens is also discussed. Finally, we report results from experimental models of HER-2/neu overexpression which have been used in an effort to understand the relationship between HER- 2/neu and response to chemotherapeutics and antiestrogens in breast cancer.     

Breast cancer: achievements in adjuvant systemic therapies in the pre-genomic era

In recent decades, the use of adjuvant systemic therapies for early breast cancer has increased extensively and has most likely contributed to the decline in breast cancer mortality observed in the U.S. and in some European countries. The last few years have witnessed accelerated progress in the treatment of early breast cancer, with the introduction of taxanes and aromatase inhibitors and, most impressively, trastuzumab to the adjuvant portfolio. When compared with anthracycline-based regimens, the addition of taxanes to treatments for patients with node-positive breast cancer has shown benefits in disease-free survival and, in some trials, in overall survival; however, these drugs are not yet universally accepted as standard treatment. Significant improvements in endocrine therapy in both pre- and postmenopausal patients with endocrine-responsive disease have been made. In the postmenopausal setting, aromatase inhibitors have shown superiority over tamoxifen in a direct comparison upfront or when given in sequence after 2-5 years of tamoxifen, but the optimal modality of administration remains unclear. For premenopausal women, ovarian function suppression with luteinizing hormone-releasing hormone analogues combined with tamoxifen has generated similar results to cyclophosphamide, methotrexate, 5-fluorouracil (CMF)-based regimens. Recently, trastuzumab has had a dramatic impact on the evolution of human epidermal growth factor receptor 2 (HER-2)-positive early breast cancer treated with standard adjuvant modalities; specifically, relapses, including distant relapses, have been halved. In this review, we summarize these main achievements, discuss the currently available adjuvant treatment options for breast cancer patients, and emphasize the need for more efficient translational research to improve individual treatment tailoring.     

乳腺癌HER-2检测的概况与进展

人类表皮生长因子受体-2（HER-2/neu）是乳腺癌重要的预后和HER-2靶向药物治疗的预测指标，准确检测乳腺癌患者的HER-2状态对临床诊疗具有重要意义。目前美国临床肿瘤学会（ASCO）和美国病理医师学会（CAP）推荐免疫组织化学（IHC）、荧光原位杂交（FISH）和亮视野原位杂交（BISH）3种HER-2检测方法。虽存在各自的优势和不足，但在少数情况下仍无法检测部分患者HER-2的状态。银增强原位杂交（SISH）、多重连接探针扩增技术（MLPA）、定量逆转录聚合酶链反应（Q-RT-PCR）和RNA原位杂交（RNA-ISH）等新的检测方法也不断应用到HER-2检测中，因其自身的独特优势，满足了部分患者的HER-2检测需求，因而有很好的临床应用前景。本文将对这些技术的特点及其优势和存在的不足进行综述。      

雄激素受体（AR)在HER-2过表达型乳腺癌中的作用及机制研究进展

人表皮生长因子受体-2（human epidermal growth factor receptor-2,HER-2）过表达型乳腺癌是乳腺癌中具有侵袭性的亚型之一,与其他类型乳腺癌相比,此类型疾病进展迅速,易复发转移,且预后差。近年来,研究表明雄激素受体（androgen receptor,AR）在HER-2过表达型乳腺癌中高表达。因此,本文将对AR在HER-2过表达型乳腺癌中的作用机制,对预后的影响及最新研究进展进行综述,以期为未来研究提供新的思路。     

HER-2阳性乳腺癌的新辅助治疗现状及展望

人表皮生长因子受体（HER-2）高表达被视为乳腺癌预后不良的重要预测因素,但随着抗HER 2治疗药物研发的进步、新辅助治疗理念的建立及临床经验的积累,其预后已得到改善。新辅助治疗是局部晚期乳腺癌的标准治疗,并被广泛用于可手术的早期患者,以提高保乳率。新辅助治疗与术后辅助治疗同样可以改善患者的无病生存期（DFS）和总生存期（OS）。近年来曲妥珠单抗等抗HER 2靶向药物及治疗方法发展迅速,新辅助治疗为药物的研究和开发提供很好的研究平台,HER-2阳性乳腺癌新辅助治疗相关问题已成为肿瘤学关注的热点问题,本文将对此作一简要综述。     

HER-2/neu as a Predictive Marker in a Population of Advanced Breast Cancer Patients Randomly Treated Either with Single-agent Doxorubicin or Single-agent Docetaxel

PURPOSE: To evaluate the predictive value of HER-2 in a population of advanced breast cancer patients randomly treated either with single-agent doxorubicin (A) or with single-agent docetaxel (T). EXPERIMENTAL DESIGN: Patients from this study participated in a phase III clinical trial in which doxorubicin or docetaxel was administered for advanced disease. HER-2 was evaluated by IHC. In all positive cases, FISH was used to confirm the HER-2 positive status. The different cohorts of patients identified by HER-2 were examined to assess a possible relationship between HER-2 status and treatment effect. RESULTS: Tumor samples were available for 176 of the 326 patients entered in the clinical trial (54%). HER-2 positivity was observed in 20% of the study population. A statistically significant interaction was found between response rates to the study drugs and HER-2 status, with HER-2 positive patients deriving the highest benefit from the use of T (odds ratio for HER-2 positive patients treated with T = 3.12 (95% CI 1.11-8.80), p = 0.03). The interaction between HER-2 and response rates to A and T was also confirmed by a multivariate analysis. No statistically significant interaction was found between HER-2 and drugs efficacy evaluated in terms of time to progression and overall survival, although in the HER-2 negative cohort A was at least as effective as T in term of overall survival. CONCLUSIONS: These results suggest that in HER-2 positive breast cancer patients docetaxel might be more active than doxorubicin, while in HER-2 negative patients doxorubicin might be at least as effective as docetaxel. Although the present results cannot have an impact on current practice, they allow us to formulate the hypothesis that HER-2 positive breast cancer is a heterogeneous disease with regard to sensitivity to anthracyclines and taxanes, and that this might be dependent upon other molecular markers including the p-53 and topoisomerase II alpha genes. This hypothesis is currently being tested prospectively in two different 'bench to bed-side' clinical trials.     

贵州省720例乳腺癌HER-2的表达情况及抗HER-2治疗的回顾性分析

背景与目的：乳腺癌是严重威胁女性生命的恶性肿瘤之一,在我国汉族与其他少数民族乳腺癌的发病率及其HER-2基因表达差异成为学者关注的问题。该研究旨在分析贵州省乳腺癌HER-2基因表达的民族差异性,评价应用曲妥珠单抗行分子靶向治疗的临床疗效,探讨多种临床因素对贵州省乳腺癌患者生存预后的影响。方法：回顾性分析2007年1月—2013年12月在贵州医科大学附属肿瘤医院接受治疗的720例女性乳腺癌患者的随访情况,采用SPSS 17.0中的Kaplan-Meier法对患者进行生存分析,统计患者无病生存期(disease free survival,DFS)及总生存期(overall survival,OS),采用Log-rank检验进行因素间比较。采用Cox回归模式进行多因素检验,分析乳腺癌的独立预后因素。结果：入组的720例患者中,HER-2阴性表达520例(72.2%),HER-2阳性表达200例(27.8%)。200例HER-2阳性乳腺癌患者中,汉族177例(177/645,27.4%),少数民族23例(23/75,30.7%)。200例HER-2阳性乳腺癌患者中,行抗HER-2治疗37例(18.5%),未行抗HER-2治疗163例(81.5%),可分为治疗组及对照组。统计分析显示,治疗组与对照组的DFS和OS差异均有统计学意义(P=0.041和0.022)。Cox回归分析提示,雌激素受体(estrogen receptor,ER)和Ki-67是入组乳腺癌患者的独立预后因素(P=0.03和0.016),孕激素受体(progesterone receptor,PR和HER-2不是独立预后因素(P均>0.05);其中汉族乳腺癌患者的ER和Ki-67是独立预后因素(P=0.018和0.031),PR和HER-2不是独立预后因素(P均>0.05);少数民族乳腺癌患者的ER、PR、HER-2和Ki-67均不是独立的预后因素(P均>0.05)。结论：HER-2基因阳性表达不具有民族差异性。HER-2阳性患者应用曲妥珠单抗行抗HER-2治疗可明显改善预后,延长DFS及OS,但目前贵州省行抗HER-2治疗人群不足20%。本研究初步提示ER、Ki-67作为乳腺癌独立的预后因素具有民族差异性的趋势。     

HER-2 阳性晚期乳腺癌治疗策略

HER-2 阳性晚期乳腺癌患者预后差,以抗HER-2 靶向治疗为基础的综合治疗显著延长了患者的生存期、改善了预后。目前多种抗HER-2 靶向药物已应用于临床,抑制HER-2 通路是HER-2 阳性晚期乳腺癌患者一线治疗及一线治疗进展后的基础治疗。本文简要介绍HER-2 阳性晚期乳腺癌治疗相关的关键临床研究、指南推荐及今后的研究方向,以指导临床实践。      

Management of male breast cancer

The management of male breast cancer is still under discussion due to lack of information from prospective, randomized clinical trials and low incidence of this disease. Current management is based largely on extrapolation from data related to treatment of female breast cancer. Over the last two decades, several review articles have discussed mainly retrospective and anecdotal data related to hormonal and chemotherapy treatment modalities. In this review, we present the most recent information and future considerations related to the management of male breast cancer. In addition to the conventional treatment options we will discuss the possible role of targeted therapy. Establishing a national or global registry for male breast cancer will provide more precise information about the natural history of the disease and will facilitate the design and execution of prospective, randomized multicenter clinical trials.     

曲妥珠单抗生物仿制药治疗HER-2阳性乳腺癌的临床研究进展

近年来,研究证明曲妥珠单抗可以显著改善人表皮生长因子受体-2（human epidermal growthfactor receptor 2,HER-2）阳性乳腺癌患者的生存预后,但由于其价格高昂,使患者选择受限。曲妥珠单抗生物仿制药的诞生有望节约成本、增加药物可及性,近年来已得到迅速发展。YL-1401O（Ogivri）、CT-P6（Herzuma）、SB3（Ontruzant）、PF-05280014（Trazimera）和ABP980（Kanjinti）,它们现已被美国食品药品监督管理局（Food and Drug Administration,FDA）批准用于HER-2阳性乳腺癌;我国HLX02已被欧洲药品管理局（The European Medicines Agency,EMA）和国家药品监督管理局（National Medical Products Administration,NMPA）批准上市。本文就近几年曲妥珠单抗生物仿制药在HER-2阳性乳腺癌中的研究进展进行综述,以期为HER-2阳性乳腺癌的靶向治疗提供参考。     

Liver metastases from breast cancer: management of patients with significant liver dysfunction

The liver is a common site of metastases in breast cancer. Although the development of liver metastases has long been associated with a poor prognosis in this disease, this dogma has been challenged by more recent data, perhaps reflecting some treatment and other technological advances achieved in the last decade. Nevertheless, the specific population of breast cancer patients presenting with liver disease and associated liver dysfunction remain poorly studied. These women still seem to have a poor prognosis as compared to other patients with liver metastases. This is further complicated by the fact that the most active cytotoxic agents in breast cancer have significant hepatic metabolism and/or biliary excretion. Unfortunately, since these patients have been most of the time excluded from clinical trials, there are currently no clear recommendations for the management of such dramatic presentations. With some exceptions, recommendations for dose adjustments have also been largely empirical. In this paper, we review the optimal doses of cytotoxics used in this clinical situation and provide some tips on the management of these patients, based on the limited data currently available in the literature.     

The Role of Liposomal Anthracyclines in Metastatic Breast Cancer

Anthracyclines (doxorubicin and epirubicin) have traditionally occupied a central place in the treatment of early and advanced breast cancer. In patients with metastatic breast cancer (MBC), anthracycline containing regimens have been shown to be superior in terms of activity and efficacy to non antharcycline containing regimens. However, the incidence of cardiac toxicity related to conventional anthracycline use prevents their administration especially in advanced disease, where higher cumulative doses are needed due to the wide use of these agents in the adjuvant setting. In more recent years, new liposomal formulations of doxorubicin, mainly non pegylated doxorubicin (NPLD) and pegylated doxorubicin (PLD), were developed and are now available for clinical use in MBC. Both agents showed a level of activity and efficacy similar to conventional anthracyclines in head to head comparisons, with an improved cardiac safety profile. This peculiarity also led to the development of very active and safe combinations with trastuzumab in HER-2 positive disease, opening new treatment scenarios in this setting. This review summarizes available evidence on the use of liposomal anthracyclines in advanced breast cancer, including HER-2 positive disease.     

Factors predictive of response to hormone therapy in breast cancer

AIMS AND BACKGROUND: Approximately half of metastatic breast cancers expressing estrogen and/or progesterone receptors responds to endocrine therapy, and postoperative adjuvant endocrine therapy provides about a 50% reduction in the development of recurrent disease. A number of publications have focused on the correlation of biomarkers, in particular estrogen and progesterone receptors and HER-2/neu status as well as different gene profiles, multigene assays and genetic polymorphisms with response to hormone therapy. The purpose of this article is to review the literature to identify biological markers predictive of response to tamoxifen and aromatase inhibitors. METHODS: A computerized literature search through Medline and ASCO abstract databases was performed, applying the words "endocrine therapy" and "predictive markers" and each of the following: early and metastatic breast cancer, estrogen receptors, progesterone receptors, HER2/neu, multigene assays, polymorphisms. The last search was updated in June 2007. In the examined literature, biological markers were retrospectively assayed to establish whether such variables were predictive for endocrine therapy efficacy. RESULTS: The role of estrogen receptor content as a predictor of response to endocrine treatment was confirmed: benefit from endocrine treatment was directly proportional to estrogen receptor levels. Progesterone receptor status was only a strong time-dependent prognostic value, and it has not yet been validated as a predictive factor of tamoxifen efficacy. Retrospective clinical data from upfront and sequential studies of aromatase inhibitors were discordant regarding the degree of benefit of these drugs over tamoxifen according to progesterone receptor status. HER-2 positivity was associated with a significantly greater risk of endocrine therapy failure in metastatic and neoadjuvant settings. The current generation of genomic assays for tamoxifen sensitivity all contain a combination of prognostic information that it is difficult to integrate into clinical practice. CONCLUSIONS: Available clinical data are inconclusive to support preferential use of aromatase inhibitors over tamoxifen in progesterone-receptor-negative and HER-2-positive tumors, but it was also clear that lower estrogen receptors, lower progesterone receptors, and positive HER-2 are associated with lower responsiveness to any type of endocrine therapy. Tumors overexpressing HER-2 are endocrine resistant and they require the blockage of the HER-2 pathway in addition to estrogen deprivation. Recent molecular studies have shown that endocrine responsiveness is to a large extent influenced by estrogen-receptor-related pathways. In the future, the key to the correct tailoring of hormone therapy will probably be the ability to subtype estrogen-receptor-positive breast cancer.     

Breast Magnetic Resonance Imaging Indications in Current Practice

Although mammography is the primary imaging modality for the breast, it has its limitations especially withdense breast parenchyma. Breast magnetic resonance imaging (MRI) has evolved into an important adjunctivetool as it is currently the most sensitive technique for breast cancer detection. Despite this high sensitivity, overlapin the appearances of some benign and malignant breast lesions results in additional unnecessary interventionwith negative results. These false positives, in addition to high cost and limited availability, necessitate establishingproper indications for breast MRI. The literature was here reviewed for recent clinical trials, meta-analyses andreview papers which have studied this important subject. PubMed; the US national library of medicine, wasutilized to review the literature in the last twenty years. Using the obtained information, current uses of breastMRI are discussed in this paper to determine the indications which are relevant to clinical practice.     

Adjuvant trastuzumab: a milestone in the treatment of HER-2-positive early breast cancer

Up to one fourth of women diagnosed with early breast cancer (EBC) have tumors that are human epidermal growth factor receptor 2 (HER-2) positive. This is associated with a high risk of relapse and death from meta-static disease. Trastuzumab, a monoclonal antibody directed against the extracellular domain of HER-2, improves survival and quality of life in women with HER-2-positive metastatic breast cancer receiving chemotherapy. Four major adjuvant trials-Herceptin Adjuvant (HERA), National Surgical Adjuvant Breast and Bowel Project (NSABP) B-31, North Central Cancer Treatment Group (NCCTG) N9831, and Breast Cancer International Research Group (BCIRG) 006-including between them >13,000 women with HER-2-positive EBC, have investigated different adjuvant treatment approaches with trastuzumab. These trials have shown that trastuzumab reduces the 3-year risk of recurrence by about half in this population. The benefit was similar across the trials despite differences in patient populations, chemotherapy regimens, and sequencing of treatment. At a 2-year follow-up, interim results from the combined analysis of the NSABP B-31 and NCCTG N9831 trials showed a one third lower mortality for trastuzumab, and there was a trend toward an overall survival benefit in the HERA and BCIRG trials. A small Finnish trial, FinHer, investigating another regimen of trastuzumab, has also shown similarly positive results. Further follow-up of the major adjuvant trials will clarify the survival benefit for women receiving trastuzumab, as well as the optimal treatment duration (1 or 2 years). Notably, cardiac events in the trastuzumab-containing arms of these trials have remained within acceptable levels, with a slightly higher (0.6%-3.3%) incidence of congestive heart failure that mostly responded to treatment. Further follow-up will provide information on long-term cardiac safety. Overall, results from clinical trials are sufficiently compelling to consider 1 year of adjuvant trastuzumab treatment for women with HER-2-positive EBC based on the risk:benefit ratio demonstrated in these studies.     

Advances in first-line treatment for patients with HER-2+ metastatic breast cancer

Background.

The prognosis for breast cancer patients overexpressing human epidermal growth factor receptor (HER)-2 has changed with anti–HER-2–targeted therapy. Although anti–HER-2 therapy with trastuzumab and chemotherapy is the standard first-line treatment, the best therapeutic regimen has yet to be defined, and new strategies are evolving.

Methods.

A literature review of well-established and recently published trials, reviews, and ongoing clinical trials addressing first-line treatment for HER-2⁺ metastatic breast cancer patients was performed.

Results.

Taxanes are the agents most commonly used in combination with trastuzumab, but other chemotherapy drugs, such as anthracyclines, vinorelbine, and gemcitabine and triple-combination therapies including platinum compounds, capecitabine, and taxanes have been studied. The combination of aromatase inhibitors with anti–HER-2 therapies is a new therapeutic option for some patients who coexpress HER-2 and hormone receptors, although its activity observed in randomized clinical trials seems to be inferior to that of chemotherapy plus anti–HER-2 therapies. In addition, new anti–HER-2 therapies have shown activity in HER-2⁺ tumors, both alone and in combination with trastuzumab.

Conclusions.

Trastuzumab plus chemotherapy is the current standard of care for the upfront treatment of HER-2⁺ breast cancer patients, though other anti–HER-2–targeting agents may appear as new standards in the upcoming years.     

Prognostic Significance of HER-2/neu and Survival of Breast Cancer Patients Attending a Specialized Breast Clinic in Kolkata,Eastern India

Introduction: The worldwide incidence of breast cancer has increased rapidly in recent years. The scenarioof Eastern India is also showing the same trend. It is necessary to study the utility of HER-2/neu as a prognosticfactor in breast cancer survival. However, there have not been detailed studies in this respect with the breastcancer patients of Eastern India. Thus this study was conducted. Materials and Methods: In this hospital-basedstudy 86 breast cancer patients attending a breast clinic of a reputed institute of Eastern India and having invasiveductal carcinomas were observed for a period of 5 years after surgery. Associations between 5 years observedsurvival and status of ER, PR and HER-2/neu of the patients were critically evaluated. Results: There wasstatistically significant association between survival pattern for 5 years and the HER-2/neu status (p=0.00001).Better survival was observed for the patients with HER-2/neu negative tumors 67(100%) compared to HER-2/neupositive tumors 7(36.8%). Conclusion: There is strong interaction between survival and HER-2/neu expressionof breast cancer patients. Thus the patients with HER-2/neu positive tumors need to be treated aggressively.     

Heterogeneity of breast cancer and implications of adjuvant chemotherapy.

Historically, in selecting adjuvant chemotherapy for patients with breast cancer, anatomy, including tumor size and nodal status, has played the primary role. As a result of analyses of genomic and clinical data, breast cancers are now thought to be a family of diseases. Major subtypes of breast cancer include HER-2 positive disease, basal-like or triple negative tumors, and at least two types of hormonally sensitive cancers. Using the nomenclature developed in the gene expression array studies, these two types are often referred to as luminal A and luminal B. Estrogen receptor negative tumors relapse earlier than estrogen receptor positive tumors. In general, estrogen receptor negative cancers are also more responsive to chemotherapy. In contrast, estrogen positive tumors appear to be somewhat less responsive to chemotherapy, but endocrine therapy can be of substantial benefit in decreasing the risk of disease recurrence. Women with HER-2 positive disease derive significant benefit with the use of trastuzumab. The role of chemotherapy in preventing disease recurrence in patients with estrogen receptor positive tumors is being reevaluated. Recent data suggests that chemotherapy has the greatest benefit in those patients with estrogen receptor positive cancers whose tumors are HER-2 positive disease, weakly ER positive, and/or have high nuclear grade. In the future, breast cancer treatment will be more targeted to the tumor and tailored to the individual with the use of genomic and clinical data.