What is targeted therapy?
Just like there are many types of cancer, there are many ways to treat cancer. The types of treatment cancer patients will receive depends on which type of cancer they have, and patients often receive a combination of treatments.
Targeted therapy is one type of treatment that doctors may suggest when speaking with their patients. Understanding targeted therapy can help patients feel more in control as they begin treatment.
What is targeted therapy?
According to the National Cancer Institute, targeted therapy targets the changes in cancer cells that help them grow, divide and spread.
Preventing cancer from metastasizing, or spreading to other parts of the body, is a goal of treatment, as doing so dramatically improves survival rates.
Are there different types of targeted therapy?
Targeted therapies often employ one of two types of drugs. Small-molecule drugs are so tiny that they can easily enter cells. These types of drugs are used to treat cancers in which the targets are located inside the cancer cells.
Monoclonal antibodies are another type of drug used in targeted therapies. Unlike small-molecule drugs, monoclo- nal antibodies cannot easily enter cells but can attach to targets on the outer surface of cancer cells.
Am I a candidate for target therapy?
The NCI notes that most of the time tumors will need be tested to see if they contain targets of drugs used during target therapies. Such testing may require a biopsy, which involves the removal of a piece of the tumor so it can be examined for targets. Risks associated with biopsies depend on the size and location of the tumor, and doctors will explain these risks prior to conducting a biopsy.
How does targeted therapy work?
The NCI says most targeted therapies aim to interfere with specific proteins that help tumors grow and spread to other areas of the body. The following are just some of the ways that targeted therapies treat cancer.
• Assist the immune system in destroying cancer cells: Cancer cells are adept at hiding from the immune system, but some targeted therapies mark cancer cells, making it easier for the immune system to find and destroy them. Other targeted therapies may just bolster the immune system as it fights the cancer.
• Prevent cancer cell growth: Some targeted therapies interfere with the proteins that tell cancer cells to divide. This slows the uncontrolled growth of cancer that can increase the likelihood of the cancer metastasizing.
• Stop signals that help form blood vessels: In order to grow beyond a certain size, tumors need to form new blood vessels. Targeted therapies known as angiogenesis inhibitors interfere with these signals, ultimately keeping tumors small by denying the blood supply necessary for them to grow. Angiogenesis inhibitors can even cause blood vessels to die in tumors that already have the blood supply necessary to grow.
• Deliver cell-killing substances to cancer cells: In certain instances, monoclonal antibodies might be combined with toxins, chemotherapy drugs and radiation. In these instances, the antibodies attach to the surface of the cancer cells, which then take up the cancer-killing substances, causing cell death.
Are there drawbacks to targeted therapy?
Cancer cells can become resistant to targeted therapies. In such instances, targeted therapies are most effective when combined with other targeted therapies or treatments such as chemotherapy and radiation.
In addition, the structure and/or function of targets on cancer cells sometimes makes it difficult to design effective drugs necessary for targeted therapies to succeed.
Targeted therapies are a potential treatment option for cancer patients. Learn more at www.cancer.gov.