Trastuzumab is a specialized medication used in cancer treatment, specifically categorized as a targeted therapy. This approach involves a type of drug known as a monoclonal antibody. Unlike traditional chemotherapy that affects many cells, trastuzumab precisely identifies and interacts with particular features on cancer cells. This precision helps to selectively combat the disease while minimizing harm to healthy tissues.
How Trastuzumab Works
Cancer cells sometimes have an excessive amount of a protein called Human Epidermal Growth Factor Receptor 2 (HER2) on their surface. This overexpression of HER2 can lead to uncontrolled growth and division of these cells, contributing to tumor formation and progression. Trastuzumab works by specifically attaching to these overexpressed HER2 receptors on cancer cells.
Once bound, trastuzumab interferes with the signals that tell the cancer cells to grow and divide rapidly. This action blocks the unchecked proliferation that is a hallmark of HER2-positive cancers. This binding also signals the body’s immune system, prompting it to recognize and destroy the cancer cells that have the HER2 protein.
Conditions Treated with Trastuzumab
Trastuzumab is approved to treat specific types of cancer that have an overexpression of the HER2 protein. It is primarily used for HER2-positive breast cancer and HER2-positive gastric (stomach) or gastroesophageal junction adenocarcinoma.
Before a patient receives trastuzumab, HER2 testing is important. This test determines if the cancer cells overexpress the HER2 protein, as the medication is only effective for HER2-positive tumors. Trastuzumab can be used in various stages of these cancers, including early-stage disease to reduce recurrence risk, and for metastatic cancer that has spread to other parts of the body.
Receiving Trastuzumab Treatment
Trastuzumab is typically administered as an intravenous (IV) infusion, delivered directly into a vein. For some breast cancer patients, it may also be given as an injection under the skin. The initial infusion usually takes about 90 minutes, allowing for patient monitoring.
Subsequent infusions generally take less time, often around 30 minutes. The frequency of treatment varies, but it is commonly given weekly or every three weeks, depending on the specific cancer type and treatment plan. These treatments are usually carried out in a hospital or an outpatient infusion center.
Potential Side Effects and Management
Patients receiving trastuzumab may experience various side effects, including infusion-related reactions such as fever, chills, headache, and nausea. Other common side effects include fatigue, diarrhea, and muscle aches. These symptoms are often manageable with supportive care or pre-medication before infusions.
A potential side effect of trastuzumab is cardiac dysfunction, which can manifest as heart problems. This occurs because HER2 receptors are also present on normal heart muscle cells. Regular cardiac monitoring, such as echocardiograms or MUGA scans, is performed before and throughout treatment to assess heart function and detect any changes early. If heart function decreases, treatment may be temporarily suspended or discontinued, and appropriate heart failure treatments may be initiated.