The current treatment for breast cancer is a multidisciplinary and multi-modal combination. It includes surgery, chemotherapy, radiotherapy, endocrine therapy and so on. Each treatment modality has its own characteristics, and each of them works within a certain limit, which is called “therapeutic window”, meaning that it can kill cancer cells with minimal damage to human health and normal cells.
Each type of surgery, chemotherapy and radiation treatment is limited to this window, and exceeding it will cause serious damage to the body. Therefore, the current conventional breast cancer treatment can only find a balance between tumor efficacy and damage to the body, and cannot pursue the maximum efficacy, so the killing of cancer cells can only achieve a certain limit.
Medical experts and scientists are constantly researching to improve breast cancer treatment methods in order to enhance its therapeutic effect. This includes improving surgical methods, improving radiotherapy, and developing new chemotherapeutic drugs. These efforts have achieved some success, but they are far from what we want. Surgery and radiotherapy are physical means to solve biological problems, and chemotherapy is a chemical method to solve biological problems, both have their own limitations.
The occurrence of breast cancer is ultimately a biological problem, and only by having a clear understanding of the mechanism of its occurrence and development process from the biological point of view and searching for treatment methods from this process can we achieve breakthroughs and ideal efficacy. Currently, a new treatment method for breast cancer, targeted therapy, is developed on the basis of biological theory and shows unlimited development possibilities and exciting prospects.
Targeted therapy is a genetic term that refers to the action of a drug on certain specific sites (so-called targets) in the pathway of tumor development, and by striking or blocking these specific targets, the development of the tumor itself is affected and the anti-cancer effect is exerted. These targets play a key role in tumor formation, are very small, and are structured at the molecular level.
Herceptin: I’ve heard a lot about Herceptin lately. What kind of drug is Herceptin and what kind of role does it play?
Certain breast cancer cells overexpress a protein called “Her2/neu” on the surface. The “Her2/neu” protein is a receptor for growth factors, which are substances that circulate in the human bloodstream. When growth factors bind to their receptors, they stimulate cell division. Herceptin competes with growth factors to block the binding of growth factors to their receptor “Her2/neu” so that they cannot act as a stimulus for breast cancer cell division. This interference with the biological processes of the cells will eventually lead to the death of the breast cancer cells.
Herceptin as a drug has been shown to have anticancer activity in metastatic breast cancer with “Her2/neu” overexpression. The effect of Herceptin in combination with chemotherapy was first reported by the American Society of Clinical Oncology in 1998.
In this trial, 469 breast cancer patients were randomized into four groups.
1. Tysol group
2. Adriamycin and cyclophosphamide group
3. Herceptin and Tysol group
4. Herceptin, Adriamycin, and Cyclophosphamide group
The results showed significant efficacy and response in the group receiving Herceptin, but patients in the Herceptin, Adriamycin and Cyclophosphamide group had a higher rate of cardiac side effects, mainly in the form of heart failure. The Herceptin and Tysol group was better tolerated and turned out to be a classical combination.
Combinations of Herceptin with other chemotherapeutic agents, such as norviben and gemcitabine, have also been studied and have shown to promote lump reduction in breast cancer.
Several recent studies have shown that Herceptin in combination with chemotherapy or sequentially after chemotherapy in early-stage breast cancer can reduce the risk of recurrence by 50%. Three trials have tested this conclusion. Two trials started with Herceptin in combination with Tysol followed by one year of chemotherapy, and another followed Herceptin for 1-2 years after the complete completion of chemotherapy. Although many questions remain about the ideal use of Herceptin, most oncologists agree on the use of Herceptin as part of adjuvant therapy for patients with “Her2/neu” strongly positive breast cancer. Most patients now receive one year of adjuvant therapy with Herceptin (every three weeks). Cardiac check-ups are very important during the application of Herceptin therapy and should be done regularly and on time during the drug administration. MUGA (radionuclide scan) is performed regularly abroad to understand the heart function. Further studies are exploring the most appropriate route of administration and the ideal dosing interval.
Application of Herceptin after CAF treatment: I would like to know whether Herceptin is applied after CAF (cyclophosphamide, adriamycin, fluorouracil chemotherapy) treatment to prevent breast cancer recurrence or Herceptin alone?
Herceptin is a new monoclonal antibody anti-cancer drug. Approximately 30% of patients with metastatic breast cancer have variants in the Her2/neu (human endothelial growth factor receptor 2) gene, causing overexpression of the Her2/neu growth factor receptor protein on the surface of cancer cells. This overexpression is associated with a more aggressive and poor prognosis of breast cancer. Overexpression of this protein can be detected by immunohistochemistry. Patients with Her2/neu overexpression breast cancer can be treated with Herceptin under certain conditions, although the indications for this drug are still under clinical investigation.
One use of Herceptin is as a slow titration 30-90 minutes per week.
Herceptin is currently generally used alone or in combination (or sequential) with chemotherapy drugs in patients with Her2/neu overexpressed breast cancer.
Herceptin can cause heart failure. When used alone, the incidence of heart failure is 7%, of which 5% is more severe. When combined with tamsulosin, the incidence of heart failure is 11%, of which 4% is more severe. When combined with AC chemotherapy regimens (adriamycin, cyclophosphamide), the incidence of heart failure was about 28%, of which 19% were more severe.
Herceptin has combined cardiotoxicity with anthracyclines (adriamycin, epi-amycin, etc.), so these two classes of drugs are not used together.
All breast cancer patients proposed for Herceptin should be evaluated for cardiac function.
Herceptin should be used with caution in the following situations, as there are no data to assess whether it is safe to use Herceptin in these situations
1.Patients with breast cancer who have cardiac disease
2.Anthracycline-based anticancer drugs have been used (cardiotoxicity)
3, have received radiation therapy to the chest (cardiotoxicity)
4.Used drugs that may damage the heart
Other toxic side effects of Herceptin include: anemia, low white blood cell count, diarrhea.