Targeted therapy for colorectal cancer
Monoclonal antibody therapy is a targeted drug therapy being used for colorectal cancer treatment at CTCA. Monoclonal antibodies are bioengineered proteins that help leverage the body’s natural immune response to recognize, attack and destroy colorectal cancer cells. Monoclonal antibodies can be used alone or in combination with colorectal cancer chemotherapy.
Currently, medical oncologists at CTCA are using the following monoclonal antibodies to help treat metastatic colorectal cancer:
- Bevacizumab (Avastin®) aims to prevent the growth of new blood vessels to tumors. This can help cut off a tumor’s blood supply, starving the tumor of the nutrients it needs to grow.
- Cetuximab (Erbitux®) works by binding to a protein called the epidermal growth factor receptor, which exists on the surface of cells. This targeted cancer therapy helps block growth signals from reaching the inside of colorectal cancer cells, putting a stop to their division and growth.
- Panitumumab (Vectibix®) also targets and binds to the epidermal growth factor receptor, preventing growth signals from reaching the inside of colorectal cancer cells. This stops their division and growth.
Other targeted drugs we use to treat advanced colorectal cancer include ziv-aflibercept (Zaltrap®) and regorafenib (Stivarga®). Zaltrap can stop the supply of blood to tumors. Stivarga aims to block growth signals, stop the formation of new blood vessels to tumors and slow the growth of tissue that connects cancer cells.
As protocols for colorectal cancer targeted therapies continue to be approved, CTCA will make every effort to offer new treatment regimens to patients.
What is targeted therapy?
Targeted therapies are drugs or other substances designed to block the growth and spread of cancer by preventing cancer cells from dividing or by destroying them directly. While standard chemotherapy affects all cells in the body, targeted therapy directs drugs or other specially created substances (e.g., immune system proteins developed in the lab) to attack cancer cells. The goal of targeted therapy is to interfere with genes or proteins involved in tumor growth to block the spread of the disease.
By targeting specific molecules that are responsible for the growth, progression and spread of cancer, targeted therapy differs from standard chemotherapy, which attacks the disease systemically and, therefore, also damages healthy cells. Because targeted therapy specifically seeks out cancer cells, it is designed to reduce the harm to healthy cells, which may lead to fewer side effects than standard chemotherapy.
Targeted therapies serve as the foundation of precision medicine, which uses information about a person’s genes or a tumor’s DNA profile to identify additional treatment options. Tailored treatments target abnormalities that may be found in each tumor’s DNA profile. This innovation marks a shift from traditional treatments designed for the average patient, toward more precise therapies.
Targeted therapy is an evolving science, and not all cancer types may be treated with targeted drugs. Several targeted therapies have been approved by the U.S. Food and Drug Administration for use in cancer treatment, including hormone therapies, immunotherapies, signal transduction inhibitors, apoptosis inducers, gene expression modulators, angiogenesis inhibitors and toxin delivery molecules.
To help identify an appropriate targeted therapy for your cancer, your doctor may order tests to learn more about the genetic disposition, protein composition and other factors the tumor exhibits. Patients may be a candidate for targeted therapy if the cancer did not respond to other therapies, has spread, is inoperable or meets other criteria. Targeted therapy may also be combined with surgery, chemotherapy, radiation therapy or hormone therapy.
Targeted therapy may be prescribed as oral pills, administered intravenously or delivered in other ways. Targeted therapy drugs may be administered in the hospital, or prescribed in pill form and taken at home. The treatment schedule is specific to each person and his or her cancer.