HER-2 positive breast cancer: what else beyond trastuzumab-based therapy?

HER-2 is a tyrosine kinase receptor which is overexpressed in 20-25% of breast cancer patients and is associated with poor prognosis. Trastuzumab, a humanized monoclonal antibody directed against the HER-2 receptor, used alone or in combination with chemotherapy, has shown significant clinical benefit in improving survival in metastatic patients, as well as halving the recurrence rate and improving survival in early breast cancer. Even with these impressive results, the reality is that not all patients will benefit form this therapy, and in those who do, resistance to trastuzumab can often develop within 1 year of treatment initiation. Beyond trastuzumab therapy, a "second wave" of monoclonal antibodies and tyrosine kinase inhibitors has emerged. These drugs have variable properties including: 1) dual inhibition against EGFR and HER-2, such as lapatinib, HKI-272 and pertuzumab; 2) anti-angiogenesis such as bevacizumab and pazopanib; 3) anti-mTOR action such as Temsirolimus; and 4) anti-Hsp90 such as 17-AAG. When used in combination with trastuzumab, or with cytotoxic chemotherapy, or as single agents, these new anti-HER-2 strategies bear the potential of arresting the tumorigenesis process. In this article, we present the current strategies in the treatment of breast cancer patients who overexpress HER-2, with particular focus on new tyrosine kinase inhibitors that can be used in combination with or after trastuzumab therapy.     

Docetaxel/trastuzumab combination therapy for the treatment of breast cancer

Trastuzumab is a humanised monoclonal antibody that targets the extra cellular domain of human epidermal growth factor receptor-2 (HER-2), which is overexpressed in approximately 20% of human breast cancers. Clinical benefit has been shown in breast cancer patients with HER-2 amplification or overexpression when trastuzumab is used alone or in combination with chemotherapy. Docetaxel is one of the most potent chemotherapy agents in the treatment of patients with metastatic and early-stage breast cancer. The rationale for combining these two drugs is based not only on preclinical synergic data, but also on expanding clinical results. This article reviews the results of trials investigating this two-drug combination, as well as the triple combinations including docetaxel and trastuzumab with platinum salts. These combinations appear to be amongst the most active therapies for the treatment of patients with HER-2-positive breast cancer in metastatic and potentially adjuvant settings.     

Docetaxel/trastuzumab combination therapy for the treatment of breast cancer

Trastuzumab is a humanised monoclonal antibody that targets the extra cellular domain of human epidermal growth factor receptor-2 (HER-2), which is overexpressed in ~ 20% of human breast cancers. Clinical benefit has been shown in breast cancer patients with HER-2 amplification or overexpression when trastuzumab is used alone or in combination with chemotherapy. Docetaxel is one of the most potent chemotherapy agents in the treatment of patients with metastatic and early-stage breast cancer. The rationale for combining these two drugs is based not only on preclinical synergic data, but also on expanding clinical results. This article reviews the results of trials investigating this two-drug combination, as well as the triple combinations including docetaxel and trastuzumab with platinum salts. These combinations appear to be amongst the most active therapies for the treatment of patients with HER-2-positive breast cancer in metastatic and potentially adjuvant settings.     

Trastuzumab: new indication. Metastatic breast cancer, in combination with docetaxel: promising, but more evaluation is needed

(1) There is no consensus on the optimal chemotherapy for metastatic breast cancer. Patients who have never previously received chemotherapy are generally given an anthracycline-based combination of cytotoxic agents. Options for patients who have already received an anthracycline include a taxane such as paclitaxel or docetaxel. The median survival time with these treatments is only about 2 to 2.5 years. (2) Trastuzumab is a monoclonal antibody directed against HER-2, a protein overexpressed by certain tumours, including about 25% of breast tumours. In 2000, the approved indications included first-line treatment of metastatic breast cancer in combination with paclitaxel. One clinical trial had shown, albeit with a low level of evidence, a median increase in survival of about 4 to 5 months. Trastuzumab is now approved for first-line treatment of metastatic breast cancer, in combination with docetaxel. (3) Evaluation data include the results of an open-label trial comparing docetaxel + trastuzumab with docetaxel monotherapy in 186 patients. The median survival time was significantly longer with the combination (31.2 versus 22.7 months). There are no relevant comparisons with other widely used cytotoxic drugs. Indirect comparison suggests that survival is similar with docetaxel + trastuzumab and paclitaxel + trastuzumab. (4) Data on the trastuzumab-docetaxel combination confirm the known adverse effects of trastuzumab, which include heart failure and diarrhea. Trastuzumab increases the frequency of docetaxel-induced neutropenia, which carries a risk of infections. (5) In summary, the results of clinical trials show that median survival time is increased by a few months when trastuzumab is added to a cytotoxic drug. However, the best cytotoxic agent is not known, and adverse effects are poorly documented. (6) In practice, trastuzumab has only been shown to benefit a minority of women with breast cancer, namely those whose tumours overexpress HER-2. Trastuzumab therapy is an option for metastatic breast cancer treatment, provided patients are enrolled in studies designed to answer the many outstanding questions.     

Monoclonal antibodies in the treatment of cancer, Part 2.

Monoclonal antibodies used in the treatment of cancer are discussed. Monoclonal antibodies are a new class of agents targeted at specific receptors on cancer cells. In addition to having direct cellular effects, antibodies can carry substances, such as radioactive isotopes, toxins, and antineoplastic agents, to the targeted cells. Five monoclonal antibodies--rituximab, trastuzumab, gemtuzumab ozogamicin, alemtuzumab, and ibritumomab tiuxetan--are available for clinical use. Rituximab is active against indolent lymphomas, providing a valuable alternative for patients with relapsed or refractory disease. Rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) increased survival over CHOP alone in patients with high-grade lymphomas. Trastuzumab has significant activity against HER-2-positive breast cancer, especially in combination with paclitaxel or an anthracycline and cyclophosphamide. Gemtuzumab ozogamicin is an active second-line therapy in older patients with acute myelogenous leukemia, but its role in combination regimens is unclear. Alemtuzumab is a valuable option for salvage therapy of patients with chronic lymphocytic leukemia. Ibritumomab tiuxetan delivers radioactive isotopes to tumor cells and is active against indolent lymphomas in patients who have relapsed after chemotherapy or rituximab therapy. The most common adverse effects of monoclonal antibodies are myelosuppression, infusion-related reactions, and hypersensitivity reactions. Rituximab may cause tumor lysis syndrome, arrhythmias, and pulmonary dysfunction. Alemtuzumab causes immunosuppression, increasing the risk of infection. Gemtuzumab ozogamicin may cause hepatotoxicity, and trastuzumab may cause significant pulmonary or cardiac toxicity. Investigational monoclonal antibodies include edrecolomab and tositumomab. Monoclonal antibodies have a significant role in the management of patients with advanced refractory or relapsed lymphomas and leukemias.     

Monoclonal antibodies in the treatment of cancer, Part 1.

Monoclonal antibodies used in the treatment of cancer are discussed. Monoclonal antibodies are a new class of agents targeted at specific receptors on cancer cells. In addition to having direct cellular effects, antibodies can carry substances, such as radioactive isotopes, toxins, and antineoplastic agents, to the targeted cells. Five monoclonal antibodies--rituximab, trastuzumab, gemtuzumab ozogamicin, alemtuzumab, and ibritumomab tiuxetan--are available for clinical use. Rituximab is active against indolent lymphomas, providing a valuable alternative for patients with relapsed or refractory disease. Rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) increased survival over CHOP alone in patients with high-grade lymphomas. Trastuzumab has significant activity against HER-2-positive breast cancer, especially in combination with paclitaxel or an anthracycline and cyclophosphamide. Gemtuzumab ozogamicin is an active second-line therapy in older patients with acute myelogenous leukemia, but its role in combination regimens is unclear. Alemtuzumab is a valuable option for salvage therapy of patients with chronic lymphocytic leukemia. Ibritumomab tiuxetan delivers radioactive isotopes to tumor cells and is active against indolent lymphomas in patients who have relapsed after chemotherapy or rituximab therapy. The most common adverse effects of monoclonal antibodies are myelosuppression, infusion-related reactions, and hypersensitivity reactions. Rituximab may cause tumor lysis syndrome, arrhythmias, and pulmonary dysfunction. Alemtuzumab causes immunosuppression, increasing the risk of infection. Gemtuzumab ozogamicin may cause hepatotoxicity, and trastuzumab may cause significant pulmonary or cardiac toxicity. Investigational monoclonal antibodies include edrecolomab and tositumomab. Monoclonal antibodies have a significant role in the management of patients with advanced refractory or relapsed lymphomas and leukemias.     

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。     

‘Simply stunning’ – trastuzumab in HER2-positive breast cancer

Human epidermal growth factor receptor-2 (HER-2)-positive metastatic breast cancer is a more aggressive disease than HER-2-negative metastatic breast cancer. The initial Phase III trial with the HER-2 antibody, trastuzumab, in this cancer suggested that, although trastuzumab was beneficial, cardiac adverse events would prevent it from being widely used. Recently trials suggest that, with close monitoring of left ventricular ejection fraction, trastuzumab can be used concurrently or sequentially with the standard adjuvant treatment of HER-2-positive metastatic breast cancer with good benefit. Therefore, with appropriate regimens, trastuzumab will be able to be used routinely in the treatment of HER-2-positive metastatic breast cancer.     

Synergistic interaction between trastuzumab and EGFR/HER-2 tyrosine kinase inhibitors in HER-2 positive breast cancer cells

Overexpression of HER-2 in breast cancer is frequently associated with expression of EGFR, and EGFR expression influences response to HER-2 inhibition. The aim of this study was to examine the effects of combining dual inhibition of EGFR and HER-2, using trastuzumab, gefitinib and lapatinib, in HER-2 overexpressing breast cancer cells. Combination proliferation assays were performed in two HER-2 positive breast cancer cell lines, SKBR-3 and BT-474. Trastuzumab combined with lapatinib was also tested in BT-474 xenografts. In proliferation assays, dual targeting with trastuzumab and gefitinib or lapatinib showed synergy or additivity in both SKBR-3 and BT-474 cells. Trastuzumab (10 nM) or gefitinib (5 μM) alone did not induce significant apoptosis, whereas lapatinib (0.75 μM) induced significant apoptosis in SKBR-3 cells. Trastuzumab combined with lapatinib further enhanced apoptosis induction. Trastuzumab (10 nM) and gefitinib (5 μM) induced apoptosis comparable to lapatinib alone (0.75 μM), suggesting that inhibition of both EGFR and HER-2 may be required to induce apoptosis in these cells. Pre-treatment with trastuzumab and gefitinib or lapatinib enhanced response to chemotherapy in vitro. The combination of trastuzumab and lapatinib also effectively blocked tumour growth in vivo. Dual targeting of EGFR and HER-2, by combining trastuzumab with EGFR/HER-2 tyrosine kinase inhibitors, may improve response in HER-2 overexpressing breast cancer cells that also express EGFR.     

The immunocytokine scFv23/TNF targeting HER-2/neu induces synergistic cytotoxic effects with 5-fluorouracil in TNF-resistant pancreatic cancer cell lines

Human pancreatic tumor cells are highly resistant to both tumor necrosis factor (TNF) and to chemotherapeutic agents. HER-2/neu expression has been proposed as a negative prognostic marker in pancreatic intraepithelial neoplasia. Our approach was to utilize HER-2/neu expression on the surface of tumor cells as a therapeutic target employing scFv23/TNF, immunocytokine composed of a single chain Fv antibody (scFv23) targeting the HER-2/neu and the cytokine TNF as the cytotoxic moiety, to deliver TNF directly to TNF-resistant pancreatic tumor cells. Using a panel of human pancreatic cell lines, which overexpress HER-2/neu, we evaluated the in vitro response of cells to TNF, scFv23/TNF, Herceptin, and a combination of scFv23/TNF with various chemotherapeutic agents. We found that all pancreatic cancer cell lines were highly resistant to the cytotoxic effects of TNF and that scFv23/TNF was highly cytotoxic to TNF-resistant HER-2/neu-expressing pancreatic cancer cell lines at levels rivaling that of conventional chemotherapeutic agents. Combination studies demonstrated a synergistic cytotoxic effect of scFv23/TNF with 5-fluorouracil (5-FU) in TNF-resistant pancreatic cancer cell lines. Mechanistic studies demonstrated that the 5-FU plus scFv23/TNF combination specifically resulted in a down-regulation of HER-2/neu, p-Akt and Bcl-2 and up-regulation of TNF-R1. In addition, the combination 5-FU plus scFv23/TNF induced apoptosis and this synergistic effect was dependent on activation of caspase-8 and caspase-3. Delivery of the cytokine TNF to HER-2/neu expressing pancreatic tumor cells, which are inherently resistant to TNF using scFv23/TNF may be an effective therapy for pancreatic cancer especially when utilized in combination with 5-FU.     

Anti-erbB-2 antibody trastuzumab in the treatment of HER2-amplified breast cancer

Human epidermal growth factor receptor-2 (HER2/erbB-2) is a member of a family of four transmembrane receptor tyrosine kinases that regulate cell growth, survival and differentiation via multiple signal transduction pathways. Amplification of the HER2 gene occurs in 20–25% of human breast cancers. This amplification event is an independent adverse prognostic factor as well as a predictive factor for increased response to doxorubicin-based combination chemotherapy, response to trastuzumab and decreased response to hormonal therapy. Methods for detecting protein overexpression or gene amplification in clinical tumor specimens include immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) techniques, with the latter considered by some to be more accurate. Trastuzumab (Herceptin) is a recombinant humanized monoclonal antibody which targets an epitope in the extracellular domain of the HER2 protein. Preclinical models demonstrated that this antibody has significant anti-tumor activity as a single agent and has synergy with certain chemotherapeutic drugs. Phase II and III clinical trials performed in women with metastatic breast cancer that overexpress HER2 have shown that trastuzumab has clinical activity when used as first-, second- or third-line monotherapy, and improves survival when used as first-line therapy in combination with chemotherapy. Newer combinations with numerous chemotherapeutic drugs have also shown significant clinical activity in phase II studies. In all of these trials, trastuzumab was generally well-tolerated, but cardiac toxicity (particularly when the antibody was combined with anthracyclines) was an unexpected adverse effect. Although trastuzumab is currently usually administered on a weekly intravenous schedule, evidence suggests that a triple dose of the drug given once every three weeks has a pharmacokinetic profile expected to be equally efficacious. Neither the optimal schedule nor the optimal duration of trastuzumab therapy has yet been clearly defined in controlled clinical trials. Current clinical investigations of trastuzumab include its use in both the adjuvant and neoadjuvant settings as well as in combination with other chemotherapy drugs or new biologic targeted agents.     

Opinion on the use of the antitumor drug trastuzumab (Herceptin) in patients with metastatic breast cancer in the county Mecklenburg-Vorpommern.

The recombinant humanized anti-HER-2 monoclonal antibody trastuzumab (Herceptin) is directed against the human epidermal growth factor receptor on the surface of breast cancer cells. Herceptin was approved in Germany in September 2000 after evaluation in clinical trials involving women with metastatic breast cancer who had tumors overexpressing HER-2/neu. A prerequisite for its use is the diagnosis of the HER-2/neu receptor status in individual patients because trastuzumab is only effective in patients with a high (score +3) overexpression of the HER-2/neu receptor. The only approved diagnostic method is the immunohistochemical DAKO-Hercep test. Clinical experience with this novel biological agent has been obtained in 2 Phase III trials involving 469 and 222 patients, where trastuzumab was used as first- or second-line therapy. The addition of trastuzumab to chemotherapy regimens was associated with longer time to progression, a higher rate and duration of response and longer survival. When used as a single agent in metastatic breast cancer that had progressed after chemotherapy, there was an overall response rate of 15%. The median duration of response was 9.1 months and median survival was 13 months. Unwanted effects included potentially severe cardiotoxicity and in 40% of patients infusion-associated fever and/or shivering that usually occurred only during the first infusion. In patients with moderate HER-2/neu expression, unwanted drug effects outweigh a relatively weak therapeutic effect. In cases of high overexpression, the cancer may go into regression and survival may be prolonged with a relatively small impairment in the life quality. The costs of trastuzumab-therapy are high amounting to an additional 48,000 DM per patient per year. Recommendations for diagnosis and therapy in Mecklenburg-Vorpommern have been formulated in discussions between oncologists, practitioners, scientists and regulatory authorities.     

Trastuzumab,a humanized anti-HER2 monoclonal antibody,for the treatment of breast cancer

The HER2/neu gene encodes a 185 kDa transmembrane receptor (HER2) that belongs to the epidermal growth factor receptor family and has intrinsic tyrosine kinase activity. HER2 is overexpressed in 25-30% of breast cancers and is suggested to have a direct role in the pathogenesis and clinical aggressiveness of HER2 overexpressing tumors. A murine monoclonal antibody, 4D5, directed against the extracellular domain of HER2, is a potent inhibitor of growth of human breast cancer cells overexpressing HER2 in vitro and in xenograft models. To facilitate clinical investigation, 4D5 was humanized by inserting the complementary determining regions of 4D5 into the framework of a consensus human IgG1. The resulting recombinant humanized anti-HER2 MAb, trastuzumab, was found to inhibit the growth of human cancer cells and tumor xenografts overexpressing HER2. Data from phase II trials in women with breast cancer whose tumors overexpress HER2 have shown that trastuzumab has a favorable toxicity profile, is active as a single agent and induces long-lasting objective tumor responses. In combination studies, there was no evidence that trastuzumab enhanced the toxicity of cisplatin and the pharmacokinetic parameters of trastuzumab were unaltered by coadministration of cisplatin. Furthermore, clinical response rates were higher than those reported with either agent alone in a similar patient population. Results of a multicenter, phase III clinical trial of chemotherapy (doxorubicin- or paclitaxel-based) plus trastuzumab as compared to chemotherapy alone in patients with advanced breast cancers overexpressing HER2 showed a significant enhancement in the effects of chemotherapy on time to disease progression, response rates and survival with coadministration of trastuzumab, without increases in overall severe adverse events. Myocardial dysfunction syndrome, similar to that observed with anthracyclines, was reported more commonly with chemotherapy plus trastuzumab. Positive results from clinical studies led to the approval of trastuzumab in the U.S in October 1998 for the treatment of metastatic breast cancer in patients with tumors overexpressing HER2. Since then, the MAb has also been marketed in Switzerland and Canada.     

Trastuzumab and chemotherapy after the treatment failure of lapatinib for HER2-positive metastatic breast cancer

We describe a patient with human epidermal growth factor receptor type 2 (HER2/c-erbB-2)-positive metastatic breast cancer who survived for approximately 6 years after the initiation of combination therapy with trastuzumab and varying types of chemotherapeutic agents. The patient was a 48-year-old postmenopausal female who underwent partial mastectomy with axillary node dissection for cancer of the right breast in March 1994. She developed lung metastases 2 years thereafter, but survived free of relapse for 8 years following chemotherapy and pulmonary lobectomy. The patient failed to respond to lapatinib, a HER1 (EGFR)/HER2 tyrosine kinase inhibitor, received during the course of her treatment but then again responded to subsequently administered trastuzumab. Primary treatment with trastuzumab and paclitaxel was initiated in April 2004 when the patient developed hepatic metastases 8 years after undergoing surgery for lung metastases. Long-term combination therapy with continued trastuzumab and a variety of chemotherapeutic agents was administered for 6 years without any significant adverse events. We discuss the treatment strategies for HER2-positive breast cancer and the role of lapatinib, a recently approved anticancer drug.     

Trastuzumab: a review of its use in the treatment of metastatic breast cancer overexpressing HER2.

Trastuzumab is a humanised monoclonal antibody developed to target the HER2 receptor which is overexpressed by some cancer cells, including 25 to 30% of breast cancers. Binding with high affinity to the extracellular domain of HER2, trastuzumab inhibits the proliferation of tumour cells that overexpress HER2. A large well designed multicentre study found that the addition of trastuzumab to either an anthracycline plus cyclophosphamide or to paclitaxel, as first-line therapy for metastatic breast cancer overexpressing the HER2 receptor, significantly increased time to disease progression, rate of objective response, duration of response and survival compared with chemotherapy alone. Single-agent trastuzumab was associated with an objective response in 15% of extensively pretreated patients with metastatic breast cancer overexpressing HER2, and 26% of previously untreated patients. Patients with a HER2 overexpression level of 3+ using immunohistochemical (IHC) assay or a positive HER2 result using fluorescence in situ hybridisation (FISH), benefit more from trastuzumab therapy than those with tumours overexpressing at a level of 2+. Trastuzumab has demonstrated synergistic action with several chemotherapy agents preclinically but the optimal combination clinically is yet to be determined. Trastuzumab is generally well tolerated by most patients; the most significant adverse effects being acute fever and/or chills and the potential to cause cardiac dysfunction. Serious adverse events, including anaphylaxis and death, have occurred in 0.25% of patients. Symptomatic or asymptomatic cardiac dysfunction occurred in 27% of patients receiving an anthracycline and cyclophosphamide combined with trastuzumab. Thus, combination therapy with anthracyclines is not recommended. Symptomatic or asymptomatic cardiac dysfunction occurred in 13% of patients receiving trastuzumab plus paclitaxel and in 4.7% of patients receiving trastuzumab alone. CONCLUSION: Intravenous trastuzumab is effective as a single-agent, and in combination with chemotherapy it significantly improves the median time to disease progression and survival time in patients with metastatic breast cancer overexpressing the HER2 receptor compared with chemotherapy alone. Cardiotoxicity is the main concern with therapy; particularly in patients with pre-existing cardiac dysfunction, the elderly and in combination with, or following, anthracyclines. Trastuzumab is indicated for use with paclitaxel as first-line therapy or as a single agent in second- or third-line treatment regimens for patients with metastatic breast cancer overexpressing HER2. Investigation is ongoing to ascertain the optimal combination regimen containing trastuzumab and antineoplastic agents. In addition, current research is focusing on the optimal timing, sequencing and duration of therapy as well as administration in the neoadjuvant and adjuvant setting.     

Promising molecular targeted therapies in breast cancer

In recent years, there has been a significant improvement in the understanding of molecular events and critical pathways involved in breast cancer. This has led to the identification of novel targets and development of anticancer therapies referred to as targeted therapy. Targeted therapy has high specificity for the molecules involved in key molecular events that are responsible for cancer phenotype such as cell growth, survival, migration, invasion, metastasis, apoptosis, cell-cycle progression, and angiogenesis. Targeted agents that have been approved for breast cancer include trastuzumab and lapatinib, directed against human epidermal growth factor receptor 2 (HER2) and bevacizumab, directed against vascular endothelial growth factor (VEGF). Several other targeted agents currently under evaluation in preclinical and clinical trials include inhibitors of epidermal growth factor receptor (EGFR), dual EGFR and HER2 inhibitors, VEGF/VEGFR inhibitors, and agents that interfere with crucial signaling pathways such as PI3K/AKT/mTOR and RAS/MEK/ERK; agents against other tyrosine kinases such as Src, insulin-like growth factor (IGF)/IGF-receptor (IGFR); agents that promote apoptosis such as Poly ADP ribose polymerase inhibitors; agents that target invasion and metastasis such as matrix metalloproteinases inhibitors and others. In this review, we highlight the most promising targeted agents and their combination with mainstream chemotherapeutic drugs in clinical trials.     

HER-2阳性早期乳腺癌辅助治疗的研究进展

人表皮生长因子受体-2(HER-2)阳性乳腺癌是具有较强侵袭性、预后较差的一类肿瘤,曲妥珠单抗抗Her-2靶向的问世,改变了Her-2阳性乳腺癌的预后.除了曲妥珠单抗这个药物,一系列抗Her-2靶向治疗药物的相继用于临床研究及治疗,包括小分子酪氨酸激酶抑制剂拉帕替尼、来那替尼;抗Her-2分子异源二聚化的药物帕妥珠单抗以及曲妥珠单抗-细胞毒性的共轭药物(T-DM1).本文就是对HER-2阳性早期乳腺癌的辅助治疗进行综述评价.     

Pharmacology and therapeutic use of trastuzumab in breast cancer.

The development, pharmacology, safety, efficacy, and dosage and administration of trastuzumab are reviewed. The discovery of HER2 gene amplification in up to 30% of women with breast cancer led to the development of trastuzumab, a humanized recombinant monoclonal antibody directed against the HER2-receptor protein on breast cancer cells. In large, multicenter trials of trastuzumab as a single agent or in combination with chemotherapy as first-line or second-line therapy for metastatic breast cancer (MBC), response rates have ranged from 12% to 23% for single-agent trastuzumab and from 25% to 62% for trastuzumab plus chemotherapy. Trastuzumab increased time to disease progression and survival time when administered in combination with chemotherapy. The National Comprehensive Cancer Network guidelines for the treatment of breast cancer now include trastuzumab and paclitaxel as an option for patients with MBC or recurrent breast cancer in which the HER2-receptor protein is overexpressed. Trastuzumab is administered weekly, with an initial i.v. dose of 4 mg/kg followed by weekly doses of 2 mg/kg. Most clinical trials continued treatment until disease progression occurred. Adverse effects include infusion-related reactions manifested by fever and chills, exacerbation of chemotherapy-induced gastrointestinal toxicity and myelosuppression, and cardiotoxicity. Trastuzumab, either as a single agent or in combination with chemotherapy, can be an effective therapeutic option for MBC patients who overexpress the HER2-receptor protein and has changed the standard of care.     

Single-agent trastuzumab versus trastuzumab plus cytotoxic chemotherapy in metastatic breast cancer: a single-institution experience

Trastuzumab has shown significant single-agent activity in patients with Her-2/neu overexpressing metastatic breast cancer, and increased response rates, progression-free and overall survival when added to standard chemotherapy. Despite higher response rates, the combination with chemotherapy has higher toxicity and it remains unknown whether single-agent trastuzumab is equally effective as the combined treatment in terms of progression-free and overall survival. We therefore carried out a retrospective multivariate analysis of 117 patients with Her-2/neu overexpressing metastatic breast cancer who were treated with trastuzumab with or without chemotherapy at a single institution between November 1999 and December 2003. Response rates tended to be higher in patients receiving trastuzumab in combination with chemotherapy (34 versus 8%, p=0.060). However, this did not translate into a benefit in progression-free survival: median (95% confidence interval) progression-free survival was 6.2 (4.45-7.95) months in patients receiving trastuzumab plus chemotherapy versus 4.2 (1.77-6.63) months in those receiving single-agent trastuzumab (p=0.560). Likewise, no significant difference in overall survival was observed: 27.0 (19.9-34.0) versus 23.1 (16.2-30.0) months (p=0.809). We conclude that in the absence of extensive visceral involvement necessitating a higher response rate, single-agent trastuzumab may be a safe and less-toxic alternative to its combined use with other chemotherapy agents. This needs to be confirmed in prospective randomized trials.     

Esophagogastric cancer: integration of targeted therapies into systemic chemotherapy

Although combination chemotherapy has been shown to be more effective than single agents in advanced esophagogastric cancer, the better response rates have not fulfilled their promise as overall survival times from best combination still range between 8 to 11 months. So far, the development of targeted therapies stays somewhat behind their integration into treatment concepts compared to other gastrointestinal diseases. Thus, the review summarizes the recent advances in the development of targeted therapies in advanced esophagogastric cancer. The majority of agents tested were angiogenesis inhibitors or agents targeting the epidermal growth factor receptors EGFR1 and HER2. For trastuzumab and bevacizumab, phase III trial results have been presented recently. While addition of trastuzumab to cisplatin/5-fluoropyrimidine-based chemotherapy results in a clinically relevant and statistically significant survival benefit in HER 2+ patients, the benefit of the addition of bevacizumab to chemotherapy was not significant. Thus, all patients with metastatic disease should be tested for HER-2 status in the tumor. Trastuzumab in combination with cisplatin/5-fluoropyrimidine-based chemotherapy is the new standard of care for patients with HER2-positive advanced gastric cancer.