Trastuzumab mediated cardiotoxicity in the setting of adjuvant chemotherapy for breast cancer: a retrospective study

Background The incidence and management of trastuzumab-mediated cardiotoxicity outside of clinical trials has not been well described. Objective and methods The aim of the study was to retrospectively evaluate the incidence of cardiac dysfunction, characterize its natural history, and identify the degree of reversibility using cardiac MRI, in a population of HER-2 positive breast cancer patients receiving trastuzumab in the adjuvant setting. Results Out of 152 patients (mean age 52 ± 10 years), 36 (24%) developed trastuzumab mediated cardiomyopathy, the majority asymptomatic. Factors that predicted the development of trastuzumab mediated cardiac dysfunction were a pre-existing history of hypertension, smoking history, and a family history of coronary artery disease. Within 3 months of treatment with trastuzumab, there was a difference in LVEF between the normal cohort and those patients who developed LV systolic dysfunction (61 ± 5% vs. 51 ± 8%, P < 0.01). During the 6-month-followup, 34/36 patients demonstrated subepicardial linear delayed enhancement of the lateral wall of the left ventricle on cardiac MRI, suggesting trastuzumab induced myocarditis. Conclusion Approximately 1 in 4 women may develop LV systolic dysfunction after treatment with adjuvant trastuzumab, necessitating careful patient selection and close serial monitoring using noninvasive cardiac imaging.     

Trastuzumab in the adjuvant treatment of early-stage breast cancer: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND: We performed a systematic review and meta-analysis to compare treatment outcomes for human epidermal growth factor receptor (HER)-2-positive breast cancer patients receiving adjuvant chemotherapy with or without trastuzumab. METHODS: We identified randomized clinical trials comparing adjuvant chemotherapy with or without trastuzumab in patients with resectable breast cancer. Fixed-effects meta-analysis was used to combine data. RESULTS: Five eligible trials were identified, reporting outcomes on 13,493 women. Fixed-effects analysis showed disease-free survival to be superior for trastuzumab-treated patients (risk ratio [RR], 0.62; 95% confidence interval [CI], 0.56-0.68). Superiority was also observed for patients receiving trastuzumab with respect to mortality (RR, 0.66; 95% CI, 0.57-0.77), locoregional recurrence (RR, 0.58; 95% CI, 0.43-0.77), and distant recurrence (RR, 0.60; 95% CI, 0.52-0.68). Patients receiving trastuzumab with chemotherapy had a higher risk for congestive heart failure (RR, 7.60; 95% CI, 4.07-14.18) and left ventricular ejection fraction decline (RR, 2.09; 95% CI, 1.84-2.37). A higher risk for central nervous system metastasis as the first recurrence event (RR, 1.60; 95% CI, 1.06-2.40) was also noted in patients receiving trastuzumab. CONCLUSIONS: The use of trastuzumab should be considered an integral part of the adjuvant therapy of HER-2-positive breast cancer patients.     

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.     

Lapatinib: A Sword With Two Edges

Lapatinib is an oral dual tyrosine kinase inhibitor targeting EGFR1 and EGFR2 (HER2). Phase I trials have shown that lapatinib is well tolerated, with mild diarrhea and skin rush as common adverse effects, and low cardiotoxicity. Phase II and III trials provided evidences on clinical effectiveness in advanced or metastatic breast cancer and potential against brain metastases. Lapatinib is active in combination with trastuzumab and in trastuzumab-resistant patients, moreover it has synergistic action with capecitabine. Several clinical trials are in progress to explore the effectiveness of lapatinib in other combinations and against several tumor types.     

EGFR and ErbB2 are functionally coupled to CD44 and regulate shedding, internalization and motogenic effect of CD44

Activation of the ErbB family of receptor tyrosine kinases is involved in a range of human cancers. Transmembrane signaling mediated by ErbB proteins is stimulated by peptide growth factors and is blocked by monoclonal antibodies such as trastuzumab and pertuzumab. ErbB receptors exert their function in conjunction with non-ErbB proteins, e.g. CD44. Here we show that epidermal growth factor (EGF) and heregulin induce CD44 shedding in JIMT-1, an ErbB2-overexpressing cell line resistant to trastuzumab, accompanied by internalization and intramembrane proteolysis of CD44 and enhanced cellular motility. These effects of EGF and heregulin are blocked by pertuzumab. Trastuzumab inhibits the heregulin- and hyaluronan oligosaccharide-induced shedding and internalization of CD44 and their motogenic effect. Trastuzumab also blocks CD44 shedding from JIMT-1 xenograft tumors in vivo. At the same time the internalization rate of trastuzumab is increased by hyaluronan oligosaccharide treatment in vitro. Our experiments point to an unexpected, but potentially important mechanism of action of ErbB receptor-targeted monoclonal antibodies used in the treatment of cancer.     

Trastuzumab decreases the number of circulating and disseminated tumor cells despite trastuzumab resistance of the primary tumor

We have recently shown that despite of the fact that the ErbB2-positive JIMT-1 human breast cancer cells intrinsically resistant to trastuzumab in vitro, trastuzumab inhibited the outgrowth of early phase JIMT-1 xenografts in SCID mice via antibody-dependent cellular cytotoxicity (ADCC). Here we show that trastuzumab significantly reduces the number of circulating and disseminated tumor cells (CTCs and DTCs) in this xenograft model system at a time when the primary tumor is already unresponsive to trastuzumab. This observation suggests that ErbB2 positive CTCs and DTCs might be sensitive to trastuzumab-mediated ADCC even if when the primary tumor is already non-responsive. Thus, trastuzumab treatment might also be beneficial in the case of patients with breast cancer that is already trastuzumab resistant.     

A phase II study of trastuzumab and capecitabine for patients with HER2-overexpressing metastatic breast cancer: Japan Breast Cancer Research Network (JBCRN) 00 Trial

Purpose To determine the response rate and toxicity profile of trastuzumab and capecitabine in women with HER2-overexpressing advanced breast cancer. Patients and methods A total of 59 patients from 6 participating centers in Japan entered onto the study of trastuzumab and capecitabine. Eighty six percent of women had received prior chemotherapy as part of adjuvant (21.4%) or metastatic treatment (48.2%), or both (16.1%), including substantial portions of patients who had previously received either CMF (7.1%), anthracyclines (28.6%), taxanes (25.0%), or both types (25.0%) of chemotherapy. Results Responses were observed in 28 of 56 patients (overall response rate, 50%). The response rate was 65.0% in patients treated with trastuzumab and capecitabine as first-line therapy for metastatic disease, and 62.5% among HER2 +3 positive patients, while high response rates were also seen in women treated with second- or third-line therapy. Patients receiving trastuzumab and capecitabine as first-line therapy had a longer TTP than did patients receiving this treatment as second- or third-line therapy (median TTP, 280 vs. 130 days, P < 0.05). Further, patients receiving trastuzumab and capecitabine as first-line therapy had longer OS than did patients receiving this treatment as second- or third-line therapy (median OS, 780 days vs. 480 weeks, P < 0.05). The treatment-related adverse events were hand–foot syndrome (30.4%), nausea (25%), diarrhea (10.7%), stomatitis (10.7%), fatigue (7.1%), and vomiting (5.4%). However, the majority were Grade 1–2 adverse events and only six patients experienced Grade 3 adverse events. Further Grade 1 cardiac toxicity was observed in one patient, while there were no cases of alopecia and treatment-related death. Conclusion Trastuzumab in combination with capecitabine is highly active in women with HER2-overexpressing metastatic breast cancer and is well tolerated.     

Compassionate use of humanized anti-HER2/neu protein, trastuzumab for metastatic breast cancer in Japan

The HER-2/neu protein is thought to be a unique and useful target for antibody therapy of cancers overexpressing the HER-2/neu gene. The recombinant humanized anti-HER-2 monoclonal antibody, trastuzumab (Herceptin) was approved for clinical use in the US in 1998. In Japan, it was approved and later became available in June, 2001. We have treated 41 patients with metastatic breast cancer with trastuzumab purchased from the US. In this paper, the details of the patients we experienced are reviewed.     

辅助化疗联合曲妥珠单抗治疗人表皮生长因子受体-2阳性晚期或转移性乳腺癌的系统评价

目的：系统评价辅助化疗联合曲妥珠单抗治疗人表皮生长因子受体-2（HER2）阳性晚期或转移性乳腺癌的临床效果。方法：检索国内外公开发表的关于辅助化疗联合曲妥珠单抗治疗HER2阳性晚期或转移性乳腺癌的中英文文献,对纳入的研究进行比较。结果：共纳入6篇随机对照试验（RCT）研究。辅助化疗联合曲妥珠单抗治疗HER2阳性晚期或转移性乳腺癌的反应率和病理完全缓解率的风险比（RR）分别为1.46（P=0.02）和0.98（P=0.91）。结论：尽管研究存在一定的局限性,但在不考虑治疗成本的情况下,辅助化疗联合曲妥珠单抗治疗要优于标准治疗,临床上具有较强的可替代性。     

曲妥珠单抗治疗141例人表皮生长因子受体2阳性乳腺癌的回顾性分析

目的 总结曲妥珠单抗在人表皮生长因子受体2(Her-2)阳性乳腺癌患者新辅助、辅助和复发转移治疗中的临床应用经验,评价其与化疗联用的疗效.方法 对2004年1月至2008年12月门诊应用曲妥珠单抗治疗的141乳腺癌患者进行回顾性分析.随访时间为3～319个月.分析患者的无病生存时间(DFS),比较患者辅助、复发转移一线及二线使用曲妥珠单抗治疗的总生存时间(OS)、治疗失败时间(TTF)和临床有效率的差异.结果 与曲妥珠单抗治疗联用的新辅助化疗中,紫杉醇联合卡铂方案占66.7%;辅助治疗中,蒽环类和蒽环类序贯紫杉类方案占53.9%.复发转移的患者治疗后中位DFS为17个月.复发转移的患者经一线曲妥珠单抗联合化疗治疗后,临床总有效 率为84.5%,中位TTF为24个月;二线治疗有效率为44.4%,中位TTF为5个月.两者比较,差异有统计学意义(P=0.002).结论 紫杉醇和卡铂化疗联合曲妥珠单抗,值得在新辅助治疗中推广,紫杉类和蒽环类联合或序贯靶向治疗仍是辅助治疗的标准方案.转移性乳腺癌一线应用曲妥珠单抗联合化疗比二线治疗的临床有效率更高,在继续应用曲妥珠单抗的基础上改用化疗方案,可提高治疗有效率,减少治疗失败的概率.