Final answer:
The correct option for targeted therapy in HER2-positive breast cancer among the given choices is Trastuzumab (Herceptin), a monoclonal antibody. Lapatinib also treats HER2-positive breast cancer by inhibiting both autophosphorylation and signaling molecule binding, dimerization, and downstream cellular response. The concept of targeted therapy aims to reduce damage to healthy cells compared to traditional cancer treatments.
Step-by-step explanation:
The student asked about HER2-positive breast cancer and its targeted therapy options. The correct option among the provided choices for targeted therapy in HER2-positive breast cancer is Trastuzumab. Trastuzumab, known by its brand name Herceptin, is a monoclonal antibody that specifically targets the HER2 receptor, which is overexpressed in about 20-30% of breast cancers. It binds to the HER2 protein on the surface of cancer cells and inhibits the cell's ability to receive growth signals, leading to slowed or stopped tumor growth. Trastuzumab's efficacy can be further increased when used in combination with chemotherapy, improving the overall survival rate of patients with metastatic breast cancer.
Lapatinib is another drug used to treat HER2-positive breast cancer by inhibiting the autophosphorylation of the HER2 receptor, thus reducing tumor growth. It not only blocks the autophosphorylation but also affects dimerization and the consequent downstream cellular response. Answering the visual connection question, the step inhibited by Lapatinib besides autophosphorylation would be option a. (Signaling molecule binding, dimerization, and the downstream cellular response).
Targeted therapies are an integral part of cancer treatment, focusing on inhibiting specific proteins involved in cancer-associated molecular pathways, thereby reducing the collateral damage to healthy cells seen in traditional cancer therapies like chemotherapy and radiation.