Targeted therapy for bone cancer
Researchers have found that some chordomas have defects in specific genes known as c-kit, PDGFRA and PDGFRB, which are involved in regulating the growth of cells. Imatinib (Gleevec®) is a targeted drug that has been shown to be effective in some patients in treating cancers with mutations in these genes, and may sometimes be used to treat chordomas that have metastasized or returned after previous treatment.
A common treatment for some cancers that spread to the bone, such as metastatic breast cancer to bone, is Zometa®, which is in a class of drugs called bisphosphonates. Generally administered through an infusion, this targeted drug therapy is used to reduce the risk of bone complications, such as fractures.
Additional targeted drugs are being evaluated for use in other bone cancers.
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.