Lapatinib耐药性HER2阳性乳腺癌细胞株的建立及鉴定

目的:为研究HER2阳性乳腺癌细胞获得拉帕替尼耐药性的机制,建立稳定具有拉帕替尼耐药性的细胞株。方法:采用2μmol/L的拉帕替尼处理HER2阳性乳腺癌细胞BT-474,维持12个月,使细胞获得稳定耐药性。然后分别利用MTT、平板克隆和软琼脂克隆形成能力分析等方法,评价所建立耐药细胞的耐药能力。结果:所建立的耐药细胞在细胞增殖能力、平板克隆形成能力和软琼脂克隆形成能力等方面均具有耐药性。结论:建立的拉帕替尼耐药性细胞BT-474具有稳定的耐药性,为后续机制研究奠定基础。     

恩美曲妥珠单抗T-DM1在HER2阳性乳腺癌中的研究进展

T-DM1是由人源化单克隆抗体曲妥珠单抗通过连接子和细胞毒性药物DM1偶联形成的一种抗体-药物偶联物,综合了抗体的靶向性和细胞毒性药物的高效杀伤癌细胞特性,发挥双倍抗肿瘤效应的同时又降低了常规化疗药物的毒副反应。多项临床研究探索了T-DM1应用于晚期HER2阳性转移性乳腺癌的解救治疗以及早期HER2阳性乳腺癌的辅助化疗和新辅助化疗的有效性和耐受性,并展现出良好的临床应用前景。本文就T-DM1应用于HER2阳性乳腺癌的最新临床研究进展简要综述。     

RON confers lapatinib resistance in HER2-positive breast cancer cells

Lapatinib-resistance is a major problem for HER2-positive breast cancer treatment. SK-BR-3-LR, a lapatinib-resistant cell clone, was established from HER2-positive SK-BR-3 breast cancer cells following chronic exposure to lapatinib. The PI3K/AKT signaling pathway was demonstrated to be resistant to HER2 inhibition in SK-BR-3-LR cells. However, both small-molecular Recepteur d’Origine Nantais (RON) inhibitors and RON-targeted small interfering RNA (siRNA) effectively restored lapatinib sensitivity in these cells by inhibiting PI3K/AKT activation. Our results demonstrate for the first time the important role of RON in mediating lapatinib resistance and suggest that RON-targeted therapy may become a novel, promising therapeutic strategy after the failure of lapatinib treatment in patients with HER2-positive breast cancer.     

ADAM10 mediates trastuzumab resistance and is correlated with survival in HER2 positive breast cancer

Trastuzumab prolongs survival in HER2 positive breast cancer patients. However, resistance remains a challenge. We have previously shown that ADAM17 plays a key role in maintaining HER2 phosphorylation during trastuzumab treatment. Beside ADAM17, ADAM10 is the other well characterized ADAM protease responsible for HER ligand shedding. Therefore, we studied the role of ADAM10 in relation to trastuzumab treatment and resistance in HER2 positive breast cancer. ADAM10 expression was assessed in HER2 positive breast cancer cell lines and xenograft mice treated with trastuzumab. Trastuzumab treatment increased ADAM10 levels in HER2 positive breast cancer cells (p≤0.001 in BT474; p≤0.01 in SKBR3) and in vivo (p≤0.0001) compared to control, correlating with a decrease in PKB phosphorylation. ADAM10 inhibition or knockdown enhanced trastuzumab response in naïve and trastuzumab resistant breast cancer cells. Trastuzumab monotherapy upregulated ADAM10 (p≤0.05); and higher pre-treatment ADAM10 levels correlated with decreased clinical response (p≤0.05) at day 21 in HER2 positive breast cancer patients undergoing a trastuzumab treatment window study. Higher ADAM10 levels correlated with poorer relapse-free survival (p≤0.01) in a cohort of HER2 positive breast cancer patients. Our studies implicate a role of ADAM10 in acquired resistance to trastuzumab and establish ADAM10 as a therapeutic target and a potential biomarker for HER2 positive breast cancer patients.     

Duration of adjuvant trastuzumab in HER2 positive breast cancer: Overall and disease free survival results from meta-analyses of randomized controlled trials

BackgroundOne year of trastuzumab, chosen empirically, improves survival of women with early-stage, HER2-positive breast cancer but also adds substantially to cost, toxicity, and inconvenience. Longer treatment does not improve outcomes, but potentiates toxicities.MethodsMedline, Embase, and major conference proceedings were searched systematically in June 2017 to identify Randomized Controlled Trials (RCTs) comparing one year versus shorter durations of trastuzumab in adjuvant treatment of breast cancer. Reported Hazard-Ratios (HR) for Overall Survival (OS) and Disease-Free Survival (DFS), and Odds-Ratio for cardiac events, with respective 95% Confidence Intervals (CI) from each study was weighted using generic inverse-variance, and pooled in a meta-analysis. Inter-study heterogeneity and sub-group difference (based on hormone-receptors and node-positivity) were assessed using I², and chi² statistics, respectively.ResultsFour studies (n = 7614) satisfied inclusion criteria. Individual RCTs had diverse pre-specified upper-limits of 95% CI for declaring non-inferiority (range: <1.15 to <1.53). Pooled results demonstrated significant improvements in OS (HR 1.28, p = 0.04), and DFS (HR 1.24, p = 0.005) with 1 year of trastuzumab compared to shorter durations. Absence of multiplicity argument allowed for declaring superiority of 1 year of trastuzumab based on our results despite non-inferiority designs of individual trials. No influence on overall effect by duration of trastuzumab in experimental arm (9 weeks versus 6 months) was noted. No statistical interaction by hormone-receptor status and node-positivity on overall results was noticed [p(sub-group difference) 0.73, and 0.52, respectively]. Odds-Ratio for cardiac events was 2.65 (p < 0.001) favoring shorter duration.ConclusionOne year of trastuzumab prolongs overall, and disease-free survivals in women with early-stage HER2 positive breast cancer compared to shorter durations and this should remain as the standard of care. Cardiotoxicity increased significantly with the 1-year treatment.     

Expression of truncated HER2 and its prognostic value in HER2-positive breast cancer patients

Purpose

The purpose of this work was to assess the truncated form of human epidermal growth factor receptor 2 (HER2) such as p95-HER2 expression in HER2-positive breast cancer (BC) patients who developed metastatic disease after adjuvant treatment with a trastuzumab-containing regimen.

Short-duration versus 1-year adjuvant trastuzumab in early HER2 positive breast cancer: A meta-analysis of randomized controlled trials

BackgroundOne year of adjuvant trastuzumab treatment is the standard of care for early stage human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients; however, controversy remains regarding the optimal schedule of trastuzumab because the selection of the 1-year schedule was arbitrary. After the remarkable results of the PERSEPHONE trial as well as the updated final results of the PHARE trial, we performed an updated meta-analysis to reassess the efficacy and safety of shorter durations of trastuzumab.MethodsA literature search of databases was conducted to identify randomized controlled trials reporting the efficacy and cardiotoxicity of shorter-duration and standard 1-year trastuzumab treatment. The hazard ratios (HRs) of disease-free survival (DFS) and overall survival (OS), and the odds ratios (ORs) of cardiac events were also estimated and pooled.ResultsSix studies were eligible, including a total of 11,496 patients. Both DFS (HR = 1.13; 95% confidence interval [CI] = 1.03–1.25; p = 0.01) and OS (HR = 1.16; 95% CI = 1.01–1.32; p = 0.03) were significantly improved with conventional 1-year trastuzumab treatment compared with shorter treatments. The more pronounced survival benefits observed in patients with negative estrogen receptor (ER) tumor and nodal involvement should be interpreted cautiously because of the lack of interaction between the survival benefit and ER, as well as the nodal status (interaction test, ER status: p = 0.26; nodal status: p = 0.60). One year of trastuzumab treatment resulted in a substantial DFS benefit compared with shorter schedules when administered concurrently with chemotherapy (HR = 1.22; 95% CI = 1.09–1.38; p = 0.0008; p = 0.02 for the interaction test). Patients in the shorter duration group experienced significantly fewer cardiac events (OR = 0.52; 95% CI = 0.43–0.62; p < 0.00001).ConclusionsThough correlated with an increasing risk of cardiotoxicity, 1 year of adjuvant trastuzumab treatment conferred substantial survival benefits and should remain as the preferred treatment for early stage HER2-positive breast cancer. Shorter durations of trastuzumab may serve as an alternative choice for patients with cardiac disease and those at lower risk of recurrence.     

Therapeutic options for HER-2 positive breast cancer: Perspectives and future directions

During the last 15 years we have witnessed an unprecedented expansion in the drugs developed to target human epidermal growth factor receptor-2 (HER-2) positive breast cancer. Trastuzumab, pertuzumab, ado-trastuzumab emtansine and lapatinib are currently food and drug administration (FDA)-approved for the treatment of breast cancer patients with HER-2 over-expressed. However, given the amount of information gathered from years of uninterrupted clinical research, it is essential to have periodic updates that succinctly recapitulate what we have learnt over these last years and help us to apply that information in our daily practice. This review will pursue that objective. We will summarize the most relevant and updated information related to the state of the art management of HER-2 positive breast cancer in all the clinical scenarios including the adjuvant, neoadjuvant and metastatic settings. But we will also critically appraise that literature in order to highlight some key clinical concepts that should not be overlooked. Lastly, this review will also point out some of the most promising strategies that are currently being tested and may soon become available.     

HER2 discordance between primary and metastatic breast cancer: Assessing the clinical impact

Background

In the setting of breast cancer relapse, treatment decisions are typically made by utilizing HER2, estrogen, and progesterone receptor expression status of the primary breast cancer. Recently, concern regarding receptor discordance has led to recommendations for rebiopsy for all cases of metastatic disease. However, whether this is an appropriate recommendation is uncertain, particularly as the clinical implications for HER2 discordance are unknown.

Methods

We performed a literature review to identify studies assessing HER2 discordance between primary and metastatic breast cancer. These studies were then reviewed for data relating to (1) impact of clinical factors on discordance rates, (2) prognostic impact of discordance, or (3) clinical outcomes from treatment alteration due to receptor discordance. Results were analyzed qualitatively.

Results

From 60 HER2 discordance studies identified, 24 contained information of interest for this review. No clear factor promoting HER2 discordance was identified. Loss of HER2 seemed to result in worse post-relapse survival and overall survival, although these data were often confounded by lack of treatment in the setting of receptor loss. Conversely, HER2 discordance was not associated with shorter DFS. Individual patients with receptor gain appear to have benefited from addition of targeted treatment, although data are limited to case reports.

Conclusion

Evidence of HER2 discordance leading to alterations in patient outcomes is limited, highlighting the need for further research in this area. Furthermore, lack of alteration in patient outcomes suggests that a more pragmatic approach to the decision to rebiopsy may be appropriate.     

Contextualizing pertuzumab approval in the treatment of HER2-positive breast cancer patients

The use of adjuvant pertuzumab in HER2-positive early-stage breast cancer has recently been approved by the EMA on the basis of data from the APHINITY trial. Accordingly, we have produced this opinion article with the aim of putting the study data in perspective against other add-on therapeutic strategies, to clarify methodological or statistical doubts about the study, and to define the population of high-risk patients with hormone receptor-negative breast cancer that we agree, in general, should be treated. With this approval, physicians must be well prepared to place the APHINITY study data in context. It is now up to each country to ratify the EMA-approved indications and to agree on reimbursement, and doctors must optimize their use based on knowledge and discussion with patients.     

176例HER2阳性乳腺癌首发转移部位的分析

目的：分析176例HER2阳性乳腺癌患者首发转移部位与分子类型的关系,帮助判断HER2阳性乳腺癌治疗和随访策略。方法回顾性分析176例HER2阳性复发转移乳腺癌患者的临床资料,HER2阳性定义为免疫组化+++,或FISH扩增,病理为浸润性导管癌,分析术后首次复发转移的分布情况。结果176例患者中,中位年龄50岁（范围31~76岁）;首发肝转移占38.1%,其中单发肝转移占18.8%;肺转移29.0%,其中单发肺转移11.4%;肝和肺转移之间差异有统计学意义（P=0.045）;淋巴结转移42.6%（包括锁骨上下淋巴结、腹腔淋巴结、纵隔淋巴结等）,其中单发淋巴结转移19.9%;骨转移25.1%,其中单发骨转移6.3%;胸壁复发14.3%,包括仅胸壁复发的8.0%;含脑转移的4例（2.3%）;还有一些少见部位转移：卵巢转移1例,子宫转移1例。首发内脏转移占59.7%,首发即多部位转移的占34.7%。结论 HER2阳性乳腺癌转移有其特殊性,内脏和淋巴结转移多见,内脏转移中肝转移更常见。所以在辅助治疗后的随访中,除了要关注淋巴结的状况外,还要关注内脏的检查,尤其是肝和肺。同时也间接地说明不同的分子类型转移的方式是不同的,所以术后辅助化疗也应该考虑器官转移的特殊性,采取相对应的药物。     

曲妥珠单抗耐药机制及HER2阳性乳腺癌耐药后的治疗策略

曲妥珠单抗治疗人表皮生长因子受体2(Human epidermal growth factor receptor 2,HER2)阳性乳腺癌的效果确切,但高耐药率限制了其临床应用。本文对HER2阳性乳腺癌曲妥珠单抗耐药机制进行回顾与总结,并分析耐药后HER2阳性乳腺癌的治疗策略,以期为进一步的研究及临床治疗方案制定提供参考。     

Tyrosine kinase inhibitors and human epidermal growth factor receptor-2 positive breast cancer

The body of evidence investigating human epidermal growth factor receptor-2 (HER2) directed therapy in patients with breast cancer (BC) has been growing within the last decade. Recently, the use of tyrosine kinase inhibitors (TKIs) has been of particular interest in the treatment of human malignancies. This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.     

Long-term Clinical Outcome of Trastuzumab and Lapatinib for HER2-positive Metastatic Colorectal Cancer

BackgroundERBB2 amplification occurs in 5% of RAS wild-type metastatic colorectal cancer (mCRC) and it has been shown to be a target for treatment with 2 HER2-directed combinations of trastuzumab and lapatinib or trastuzumab and pertuzumab. We present long-term clinical results of trastuzumab and lapatinib (HERACLES-A trial) at 6.7 years (82 months) follow-up and focus on central nervous system (CNS) recurrences.Patients and MethodsPatients had histologically confirmed KRAS exon 2 (codons 12 and 13) wild-type and HER2-positive mCRC. HER2 positivity was assessed by immunohistochemistry and in situ hybridization HERACLES diagnostic criteria. Patients were treated with intravenous trastuzumab 4 mg/kg loading dose, then 2 mg/kg once per week, and oral lapatinib 1000 mg per day until disease progression or toxicity. Patients who presented with symptoms or signs of CNS disease received brain computed tomography scan or magnetic resonance imaging.ResultsA total of 35 patients received trastuzumab and lapatinib and 32 were evaluable for response. One patient (3%) achieved complete response (CR), 8 (25%) partial response, and 13 (41%) stable disease. Therefore, response rate was 28%. Median progression-free survival was 4.7 months (95% confidence interval [CI] 3.7–6.1). Median overall survival was 10.0 months (95% CI 7.9–15.8). One patient achieved sustained CR still maintained at 7 years of follow-up. Progression in the central nervous system (CNS) occurred in 6 (19%) of 32 patients.ConclusionsLong-term (6.7 years) follow-up analysis of HERACLES-A supports using of trastuzumab and lapatinib as treatment reference for KRAS wild-type, chemorefractory HER2-positive mCRC. In this subset of patients, prolongation of survival is accompanied by CNS recurrences that will require diagnostic and therapeutic attention in future studies.Clinicaltrials. Gov identifier: NCT 03225937.     

Trastuzumab monotherapy versus combination therapy for treating recurrent breast cancer: time to progression and survival

Background HER2 expression is an important prognostic and predictive factor of treatment efficacy in breast cancer. Trastuzumab, in particular, is a key drug in the treatment of HER2-positive recurrent breast cancer. However, the difference in treatment efficacy between trastuzumab monotherapy and combination therapy with chemotherapy is unclear. In order to elucidate this point, both treatments were compared in terms of efficacy by metastatic site, time to progression (TTP), and survival. Patients and methods The subjects were 1,471 breast cancer patients who had been evaluated for HER2 expression between 1998 and March 2006; 74 of these had recurrent breast cancer that had been treated with trastuzumab. Of these 74 patients, 39 received trastuzumab alone and 45 trastuzumab in combination with chemotherapy. The items of investigation were clinical effect, TTP, survival, biological markers such as ER/PgR, proliferation (Ki67) or p53 overexpression, nuclear grade, performance status (PS), lymph node metastasis, and tumor size. Results The HER2-positive rate was 23.3%, and the degree of malignancy in these HER2-positive patients was high; postoperative disease-free survival (DFS) was low. However, this tendency was clear in patients with hormone-responsive breast cancer. In patients with hormone-non-responsive breast cancer, HER2 negativity had a significantly higher Ki67 value, and there was no difference in DFS between patients with HER2-positive and -negative tumors. Among the 74 patients with recurrent breast cancer, the response rate to trastuzumab was 64.9%; however, among patients who received the combination treatment, the response rate was 86%. In patients with liver metastasis, the effect of trastuzumab alone was low, but that of the combination treatment was significantly high. TTP was 5.7 months and 15.9 months with trastuzumab alone and the combination therapy, respectively. Furthermore, a significant difference was seen in post-treatment survival; however, there was no significant difference in survival after a recurrence. In the multivariate analysis on factors for TTP, PS, clinical effect, and combination treatment were significant. However, good PS and early treatment were the significant factors in post-treatment survival. Conclusions The effect of trastuzumab in patients with recurrent breast cancer who received the combination treatment was significantly high and TTP was long. However, this was not a significant factor in terms of overall survival. In particular, a good PS and early treatment were important in post-treatment survival. This article is based on a presentation delivered at Symposium 3, “Molecular target therapy: basics and clinical application,” held on 30 June 2007 at the 15th Annual Meeting of the Japanese Breast Cancer Society in Yokohama.     

HER2-targeted therapy in breast cancer: A systematic review of neoadjuvant trials

Targeting human epidermal growth factor receptor 2 (HER2) during or in sequence with chemotherapy improves overall survival in metastatic and early HER2-overexpressing breast cancer. In this paper we systematically review neoadjuvant clinical trial data in HER2-positive breast cancer and discuss key unanswered clinical questions.     

PIKHER2: A phase IB study evaluating buparlisib in combination with lapatinib in trastuzumab-resistant HER2-positive advanced breast cancer

BackgroundPhosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin pathway is frequently activated in HER2-positive breast cancer and may play a major role in resistance to trastuzumab. Buparlisib is a pan-class-I PI3K inhibitor with potent and selective activity against wild-type and mutant PI3K p110 isoforms.Patients and methodsPIKHER2 phase IB study aimed primarily to determine a maximum tolerated dose (MTD) and propose a recommended phase II dose (RP2D) for buparlisib in combination with lapatinib in HER2-positive, trastuzumab-resistant, advanced breast cancer. Oral buparlisib (40, 60 or 80 mg) and lapatinib (750, 1000 or 1250 mg) were administered daily. A modified continuous reassessment method using an adaptive Bayesian model guided the dose escalation of both agents. Secondary end-points included antitumour activity and pharmacokinetic (PK) assessments.ResultsA total of 24 patients were treated across five dose levels. Dose-limiting toxicities included transaminases elevation, vomiting, stomatitis, hyperglycemia and diarrhoea. MTD was declared at buparlisib 80 mg/d + lapatinib 1250 mg/d, but toxicities and early treatment discontinuation rate beyond cycle 1 led to select buparlisib 80 mg + lapatinib 1000 mg/d as the RP2D. Main drug-related adverse events included diarrhoea, nausea, skin rash, asthenia, depression, anxiety and transaminases increase. There was no significant evidence for drug–drug PK interaction. Disease control rate was 79% [95% confidence interval [CI] 57–92%], one patient obtained a complete remission, and six additional patients experienced stable disease for ≥ 24 weeks (clinical benefit rate of 29% [95% CI 12–51%]).ConclusionCombining buparlisib and lapatinib in HER2-positive trastuzumab-resistant advanced breast cancer was feasible. Preliminary evidence of antitumour activity was observed in this heavily pre-treated population.Trial registration IDNCT01589861.