Do I need testing before targeted therapy?

Often, yes. According to the National Cancer Institute, for some types of cancer, such as chronic myelogenous leukemia (CML), most people will have a target for a certain drug, so they can be treated with it. But most of the time, your tumor will need to be tested to see if it contains targets for which there is a drug. This is called biomarker testing.

You may need to have a biopsy for biomarker testing. A biopsy is a procedure in which your doctor removes a piece of the tumor for testing. There are some risks to having a biopsy, and these vary depending on the size of the tumor and where it is located. Your doctor will explain the risks for your type of tumor.

Your healthcare team can tell you whether testing is needed in your case and what the results mean for your treatment options.