Tests You May Have for Metastatic Breast Cancer
In the time leading up to and after your diagnosis, you will have a wide variety of medical tests. These first tests help your doctors profile what kind of breast cancer you have, how quickly it is growing and where it has spread. Your providers will collect and use information from all these sources to help you make treatment decisions:
Ask for copies of all your test results, even imaging tests, for your own record-keeping. Having them on hand may make things easier if you want a second opinion or need to change doctors. If possible, get a copy of your pathology report from your first diagnosis (if you had one). Should you repeat tests now, your doctors can compare your first diagnosis pathology report to your current one to see if the cancer has changed. Between 15 and 20 percent of metastatic cancers have different traits than they did at early-stage diagnosis.
Many doctors now do a confirming biopsy, a biopsy of the metastatic site or sites to find out if the cancer cells are hormone receptor-positive or HER2-positive. A biopsy tests a sample of tissue taken from the affected site, or a lump or tumor removed with surgery. Sometimes doctors assume the cancer cells in the metastatic site have the same features as those in the breast. But current research suggests that sometimes the traits of these cells change.
A confirming biopsy may bring you the comfort of knowing more about your diagnosis. It will also help your doctors to better target your treatment. Though it’s very rare, it is possible that a confirming biopsy will find what looks like breast cancer metastasis is something else, such as a benign or non-harmful growth, or another disease.
If your metastatic diagnosis wasn’t confirmed by biopsy, it’s OK to request one or to ask your providers for a reason. In some cases, the site of metastasis may make biopsy difficult. This is true of metastases to the brain and the bone. In those cases, your doctors will rely on scans, symptoms and blood work to confirm your diagnosis.
Throughout treatment, tests help you and your healthcare team assess how your treatment plan is working and, if needed, make changes. Here are some of the tests you may have at diagnosis and during treatment for stage IV breast cancer:
You and your doctor may also consider or use these tests:
Your doctors may order a blood marker or tumor marker test, which looks for certain proteins or tumor cells in your blood. The proteins and tumor cells are small pieces that break off the cancer and enter the bloodstream. This makes it possible to find them with a blood test.
In some cases, doctors use blood marker tests to help with diagnosis. More often, they are used to monitor disease progression. Sometimes a biopsy will confirm a metastatic diagnosis, even when blood markers are not higher than they should be. Some providers prefer not to use tumor marker tests because of concerns they aren’t reliable. Talk with your doctors about their approach.