If your symptoms or test results seem to indicate that the breast cancer has come back or spread, your doctor may suggest a biopsy of the suspected cancerous tissue. You may need a biopsy to:
- rule out other non-cancer causes of the problem
- make a definite diagnosis of recurrent or metastatic breast cancer
- figure out the current "personality" of the cancer (including hormone receptor status and HER2 status) so your doctors will know how best to treat it
When breast cancer comes back, it may not be exactly the same as the first time. For example, a cancer that was hormone-receptor-positive (ER+ or PR+) may come back as hormone-receptor-negative. HER2 testing may not have been done when the cancer was originally diagnosed. But now, it's important to have this test done because the results can affect treatment. Just as you needed to understand all the details of your original diagnosis, so you also need to know what you're dealing with now. This is the first step in knowing what treatments you may require.
A biopsy can be done with a needle or a surgical knife through a little incision. This is the preferred biopsy procedure because it is the least invasive.
If you have suspicious tissue that is hard to reach, then a scan (such as an ultrasound or CAT scan) is usually done along with the needle biopsy. The images from the scan direct the biopsy needle to the correct spot in the hard-to-reach site (such as the belly, chest, bone, or lung). The biopsy needle sucks up a small amount of fluid or tissue, which is sent to a pathologist who checks it under a microscope for cancer cells.
If you have suspicious tissue in your lung near the center of the chest, your doctor may biopsy it with the help of a bronchoscope. This is a hollow tube with a light inside it that is passed through the nose or mouth into the lungs. Fluid around the lung can be removed in a procedure called "thoracentesis" where a hollow needle is inserted between the ribs to draw off fluid.
You probably won't have a biopsy if:
- Your X-ray findings clearly show a metastasis; so do test results of other parts of the body; and it hasn't been long since your last breast cancer treatment.
- The affected part of the body is difficult to reach safely for biopsy (such as the brain, spine, or eye).
- Biopsy would cause side effects, and results would not alter treatment.
- You already know the breast cancer is metastatic, so it is highly likely that a new suspected site is caused by the same cancer.
You and your doctor will decide whether to biopsy or not, which area to biopsy, and which biopsy technique to use.
The pathologist who looks at your biopsy compares it with the cells of the original breast cancer. (Slides of the first breast cancer are stored in the hospital where your surgery was done.) If the new cancer is a metastasis of the first cancer, then the two cancers usually look very similar, if not exactly alike.
But occasionally, the cancer cells in the biopsy tissue do not look like those of the original tumor. This suggests that you may have a new kind of breast cancer, or a new cancer that is different from breast cancer, such as colon, lung, or ovarian cancer. A pathologist will then do more studies to figure out what kind of cancer it is so you can get the right treatment.
If a diagnosis of recurrent breast cancer is made, your doctor will probably want to find out if cancer is elsewhere in your body by doing a "restaging" evaluation. This may include blood tests, a bone scan, X-rays, CAT scans, MRIs, and a PET scan. Unless you are having symptoms such as a headache or vision changes, you will not need a CT scan of your head.
I always tell my patients that, even though it is frightening to think of cancer in other parts of the body, we should 'know the enemy' in order to be prepared to fight it. The way we do this is to do all the tests we need at the time of first recurrence. We don't want to be surprised later on.
Jennifer Griggs, M.D., M.P.H.