Targeted Cancer Therapy

Since cancer involves the rapid reproduction of cells, most forms of treatment, like chemotherapy, target and kill rapidly dividing cells, regardless of whether or not they’re cancerous. Targeted therapy, also known as a form of precision medicine, is a new type of treatment that is becoming a focus in cancer research because it works on stopping and killing cancer cells without harming other cells, a common issue with chemotherapy.

Precision medicine involves treating a patient’s tumor based on the genetic change in the cancer cells (either in malignant blood cells or in the solid tumors themselves) and interfering with proteins that help cancers grow and spread. These medications work in a variety of ways to target the cancer, including helping the immune system destroy cancer cells, stopping the cancer cells from growing, killing the cancer cells and starving the cancer of stimulants (such as hormones)  it needs to reproduce and grow.

This therapy requires doctors to have a genetic understanding of the cancer and allows for more personalized treatment.  In some cancers like non-small cell lung cancer, forms of chronic leukemia, and types of breast cancer, these molecularly targeted therapies have become a standard of care.  It also is being studied in many clinical trials with extremely positive results. In order to receive these treatments, a patient must undergo a test to see if the genetic change being targeted is present in their tumor. This test is often a blood sample or a biopsy where the doctor removes a sample of the cancer and then the DNA is sequenced to look for genetic changes. If the changes match the targets of the therapy, the patient may be a good candidate to receive the drug. The results have been extremely promising and indicate that this may be an area where many new discoveries are made in the coming years. Several targeted medicines (such as ponatinib and brigatinib) have been approved and are widely used by patients whose cancers have been genetically defined.