Radiotherapy and chemotherapy following breast cancer surgery has long been the main treatment, but both often affect the body’s normal tissue, causing decreased blood cells, thrombocytopenia, fatigue, nausea, vomiting, hair loss, normal tissue adverse reactions such as acute injury Some can even be life-threatening. However, as the scientists of human genetic code and the clarification of the pathogenesis of breast cancer, they developed a new targeted therapy that has the role of a new class of drugs – monoclonal antibodies.
Monoclonal antibodies in the field of cancer therapy is widely used. Initially, its been widely used in disease diagnosis, detect any recurrence, prognosis evaluation. With the in-depth study, monoclonal antibodies have been used in cancer treatment.
The first monoclonal antibody drugs – Herceptin
The first clinical application of monoclonal antibody drugs are developed by pharmaceutical company Roche Herceptin (Herceptin, trastuzumab), its HER2-positive breast cancer patients is very effective, the U.S. Food and Drug Administration approved in 1998 Herceptin market.
What is HER2?
HER2, also known as the human epidermal growth factor 2, is the original encoded oncogene HER2 receptor, HER2 in regulating normal cell proliferation, growth and differentiation play an important role.
If the breast cancer cells showed that overexpression of HER2, which indicates that breast cancer patients with poor prognosis, disease-free survival and overall survival were significantly shortened and invasive tumor cells increased, chemotherapy is more prone to drug resistance. In this regard, high-dose anthracycline chemotherapy drugs (such as doxorubicin) and paclitaxel for patients with positive HRE2 relatively effective. About half of the HER2-positive breast cancer cells express estrogen and progesterone receptors, however, considerably less than the number of receptors HER2-negative breast cancer cells, so patients with HER2-positive endocrine therapy of tamoxifen and other drugs are not sensitive, it also caused trouble for the treatment of patients. For these reasons, HER2-positive breast cancer patients has greatly increased the likelihood of recurrence.
In breast cancer patients, about 20% of people over-expression of HER2, although the traditional methods for their treatment to be ineffective, but they are very suitable for Herceptin treatment, therefore, in the early diagnosis of breast cancer there is a need for HER2 testing.
The efficacy of Herceptin
Laboratory and clinical studies have shown that Herceptin can be specific and tumor cell surface expression of HER2 receptor, causing a variety of biological effects occurring within cells, including inducing tumor cell apoptosis, reduce cell surface expression of HER2 and reduce the proliferation of tumor cells and reduce tumor growth in other factors leading to the production, enhance the role of chemotherapy. Herceptin also has the role of extracellular, may induce immune cell killing tumor cells. Herceptin has little effect on normal cells, thus very few adverse reactions. Previously that the transfer has taken place Herceptin for advanced breast cancer patients with good therapeutic effect, but recent studies have shown that Herceptin for early breast cancer patients have been encouraging results.
“New England Journal of Medicine” recently published results of clinical studies of Herceptin two shocked the medical profession. One of the international multi-center randomized clinical trials, HER2-positive breast cancer patients after surgery received at least four cycles of adjuvant chemotherapy or neoadjuvant chemotherapy after one year, one-time use Herceptin every three weeks, in the Herceptin group Only 127 people recurrence of breast cancer, whereas the control group, 220 relapse. Compared with the control group, group Herceptin reduces the risk of breast cancer recurrence by 46%. Relapse about two-thirds of patients with distant metastasis of breast cancer, Herceptin group will reduce the risk of distant metastasis of breast cancer by 51%. In another test, HER2-positive breast cancer patients receiving doxorubicin and cyclophosphamide treatment, the joint use of Herceptin and Taxol, or paclitaxel alone one year of therapy, using patients who received Herceptin reduced the relapse rate 52%, and mortality of patients by 33%.
In other words, the use of Herceptin for one year, HER2-positive breast cancer patients reduces the risk of recurrence by half, while the mortality rate by one third. Meanwhile, the breast cancer patients improved quality of life can significantly reduce surgical area to reduce the risk of treatment failure and to maximize the patient’s survival. This data is from the use of tamoxifen has been the best of early breast cancer clinical trial results. United States MD Anderson Cancer Center, Dr. Hortobagye issue of assessment of writing, when excited, said: “This is simply too amazing, and such a result indicates a dramatic history of breast cancer occur in a subversive, and even cure breast cancer, have become impossible. ”
In May of this year at the ASCO meeting, a professor of oncology at Indiana University, Dr. George W. Sledge, said: “To answer whether Herceptin adjuvant therapy to improve disease-free survival rate of this question, the answer is clearly yes.” He will jointly analyze the results as “his entire professional career in the adjuvant therapy trials have seen the most shocking results.” The blood of the University of Kentucky Markey Cancer Center Oncology Dr. Edward H. Romond, associate professor, said: “He Cup Ting treatment advantages to change the current treatment standards, the use of Herceptin has been shown the benefits of the decline in relative risk. “At the same time, from the School of Medicine Mayo Clinic Jacksonville, Florida Edith A. Peterz professor said:” The joint analysis clearly demonstrated the same time, the use of Herceptin and chemotherapy drugs in patients with disease-free survival and overall survival compared with chemotherapy alone treatment group had markedly improved, which is a result of treatment status can be changed. ”
It is precisely because a significant effect of Herceptin on how early diagnosis of breast cancer patients when HER2 testing is particularly important.
Early surgery patients need to check the status of HER2
With the current availability of fresh specimens were HER2 testing, is the current status of the most powerful predictors of clinical guiding significance. Of early breast cancer radical surgery done one can check the status of the HER2 do? In fact, the original surgery to retain the pathological examination of paraffin blocks may also be HER2 test can also explain the patient’s body HER2 levels. If the hospitals are not regulated HER2 testing, it is recommended that the patient’s tumor paraffin-embedded pathological specimens sent to the standardized test has been established hospital.
Herceptin improve chemotherapy
Herceptin is not chemotherapy drugs, did not have cell toxicity, the use of Herceptin will not be seen in conventional chemotherapy side effects, such as: nausea, vomiting, leukopenia and so on.
Herceptin and chemotherapy combined with a very wide selection of pre-clinical data indicate that Herceptin with cisplatin, vinorelbine and paclitaxel has synergistic effects and adriamycin, taxol, methotrexate effects are superimposed. In the Herceptin large multi-center clinical data support the good, the first-line drugs recommended in combination with paclitaxel compared. Previously received doxorubicin and paclitaxel chemotherapy for patients with foreign research found that most physicians are willing to choose and vinorelbine combination therapy. Herceptin combined with docetaxel are also reports about good results. Herceptin combined with Xeloda showed good preliminary clinical efficacy. Abroad, there are programs and cisplatin / carboplatin or gemcitabine combined with clinical trials.
The scope of Herceptin treatment
Herceptin is currently FDA approved indication for: HER2 overexpressing metastatic breast cancer in first-line combination chemotherapy, received one or more single-agent chemotherapy in the treatment of advanced breast cancer. New clinical studies have shown that Herceptin for early breast cancer have a very good therapeutic effect.
