Targeted therapy for breast cancer

The so-called molecular targeted therapy means that when drugs enter the body, they will specifically select carcinogenic sites at the molecular level to combine and act, causing tumor cells to die specifically without affecting normal tissue cells around the tumor. Therefore, molecular targeted therapy is also called "biological missiles". It generally only has an inhibitory effect on tumors, but has fewer side effects on normal tissues. It is characterized by high efficiency and low toxicity, and is an ideal tumor treatment method.

Are targeted therapy drugs considered chemotherapy?

Targeted therapy is essentially a biological therapy, not chemotherapy. There is an essential difference between the two. Traditional chemotherapy drugs mainly refer to cytotoxic drugs, which are a kind of lethal chemical substances. In addition to killing tumor cells, they are also toxic to many normal tissue cells that also divide vigorously, such as white blood cells, platelets, gastrointestinal mucosa, hair follicles, etc. Therefore, chemotherapy often causes some related side effects, such as: white blood cell decrease, platelet decrease, nausea

What types of molecular targeted therapy drugs are used clinically?

According to the drug's target and properties, the main molecular targeted therapy drugs can be divided into the following categories: ① small molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, such as gefitinib and erlotinib; ② monoclonal antibodies against epidermal growth factor receptor, such as cetuximab; ③ monoclonal antibodies against the antigen oncogene human epidermal growth factor receptor 2, such as trastuzumab; ④ anti-vascular endothelial growth factor receptor (VEGFR) inhibitors, such as bevacizumab; ⑤ mammalian target of rapamycin protein kinase inhibitors, everolimus; ⑥ anti-CD20 monoclonal antibodies, such as rituximab, etc.

What is HER-2? How is it detected and interpreted?

The Chinese name of HER-2 (C-erbB2) is human epidermal growth factor receptor-2. Currently, the main methods used to detect HER-2 are immunohistochemistry (IHC) and fluorescent immunoblotting (FISH), both of which have their own advantages and disadvantages. IHC uses specific antibodies to detect HER-2 protein, while FISH detects the amplification of the HER-2 gene. IHC testing is simple, popular, and inexpensive, but the results are greatly affected by specimens, reagents, and technology, and sometimes false results are prone to occur. FISH is complicated, expensive, and many hospitals cannot carry out it, but the results are more accurate and objective. In general, all breast cancer specimens are tested for HER-2 by IHC, and the results are divided into several situations, such as -, +, ++, and +++. - and + are usually defined as HER-2 negative, +++ is defined as HER-2 positive (overexpression), and for ++, HER-2 may be negative or positive, and further verification is required by FISH. The results of FISH can be quantified and divided into no amplification and amplification. Patients with no amplification are defined as HER-2 negative, and patients with amplification are defined as HER-2 positive.