A breast cancer diagnosis is overwhelming and often marks a period of time in which you’ll receive many tests. Doctors will attempt to learn as much as possible through these tests — about your breast cancer type, how far it has advanced, what mutations it might contain, what the tumor cells look like, and any other clinical information that will help determine the best course of treatment. Undergoing all these tests can be very stressful, but they allow doctors to begin treating you as soon as possible.
Types of Tests You May Get Related to Breast Cancer Screening and Diagnosis
There are three types of tests related to breast cancer: screening tests, diagnostic tests, and monitoring tests. Monitoring tests happen later, after a woman is diagnosed with breast cancer and has begun treatment. They help doctors know how the treatment is working, what changes to the plan may be necessary, and whether the cancer returns after it is no longer detectable in your body.
In the early stages of possible diagnosis women can expect to undergo screening tests and diagnostic tests.
Screening tests Screenings are used to look for possible signs of breast cancer. The most common type of screening test is a mammogram, which uses low-intensity X-rays to create an image of your breast. A positive screening — one with a suspicious area in your breast — does not mean you have cancer. In fact, the majority of positive screenings are not cancer.
Diagnostic tests Diagnostic tests are used in a woman with suspected or possible cancer to determine whether or not she definitely has breast cancer. Diagnostic tests are also used to learn more information about a cancer. Diagnostic tests can include blood tests, imaging scans, molecular tests, and other testing. (1) Doctors may also use these tests to tell if the cancer has spread and, if so, how far and where. The most common diagnostic test for breast cancer is a biopsy.
What’s Involved in a Biopsy?
A biopsy is the removal of a tiny amount of tissue or fluid from your tumor or the area where cancer is suspected so that the cells can be examined under a microscope. Many women who undergo biopsies do not have cancer. But a biopsy is the main way a woman can learn whether she has cancer or not.
There are several types of biopsy procedures. The type of biopsy will depend on the size and location of the suspicious area, what it looks like how many abnormal areas exist, other health conditions a woman has, and her personal preference. (2) Usually only one biopsy is necessary to diagnose breast cancer. However, doctors may need to do additional biopsies if the first one does not provide enough tissue for testing or if doctors need more tissue to do additional tests. The types of biopsy include:
Fine needle aspiration (FNA) During an FNA, the doctor uses a thin, hollow needle to pull out a small amount of tissue from the area suspected to be cancer. (2)
Core needle biopsy A core needle biopsy uses a wider needle to withdraw tissue from the part of the breast that looks suspicious on a mammogram, ultrasound, or MRI or a part of the breast that physically feels unusual or suspicious to your doctor.
Surgical biopsy A surgical, or open, biopsy is rarer than fine needle and core needle biopsies. It involves removing all or part of a lump to conduct lab tests on it. The two types of surgical biopsies are incisional and excisional. During an incisional biopsy a doctor removes only a portion of the lump or suspicious area. During an excisional biopsy, the doctor removes the entire suspicious area and may also remove some of the normal breast tissue surrounding the area.
A pathologist will examine and analyze body tissue and cells under a microscope. The results of your biopsy will be provided in a pathology report. If doctors identify cancerous cells in the biopsied tissue, they will conduct further tests. They might also need to do a biopsy from the lymph nodes under the arms if there is concern a cancer may have spread. (3)
If the Biopsy Is Positive: More Testing
If the pathology report reveals cancer, the doctors will first want to determine what stage your breast cancer is and what grade the tumor is.
The type of tests a woman will undergo next depends on what the cancerous cells look like. Those tests include blood tests, additional biopsies, a bone scan, a chest X-ray, breast ultrasound, or other specialized imaging or chemical testing. (4)
One common imaging test is computerized tomography, or a CT scan, that takes cross-sectional X-rays of the body. Another common imaging is positron emission tomography, or PET scans, that look at cell activity. A PET scan involves injecting a person with a tiny amount of sugar substance and radioactive material so cameras can observe highlighted areas in the breast on a computer screen. (5)
Testing a Tumor’s Genomic Signature
Doctors use genomic testing to see which genes are especially active in a tumor. The activity of individual genes affects how the cancer behaves. This information will help doctors determine what treatments, if any, to use after surgical removal of your tumor. (6)
Some women will also undergo molecular testing that looks for specific mutations in cancer cells. Whether you receive this test depends on your cancer type and what doctors learn from previous tests. (7)
Other names for this type of testing include molecular profiling, next-generation sequencing, and comprehensive genomic profiling. The test looks at the entire genome — the entire set of genetic code in the cells.
The molecular test you receive might be one the cancer center has developed, or it could be one of several commercial ones: FoundationOne, IntelliGEN Oncology Therapeutic Panel, or Molecular Intelligence. (7)
Learning what mutations the cancer genes may have can help doctors determine whether you receive a targeted therapy or whether there is a clinical trial you can enroll in. A targeted therapy kills only the cancer cells with a specific gene or gene mutation.
Testing for Hormone Receptors and HER2
Some testing will reveal whether the cancer has hormone receptors, a type of protein, for estrogen or progesterone. Two of every three breast cancers involve hormone receptors.
An estrogen-receptor-positive (ER+) or progesterone-receptor-positive (PR+) cancer means that particular hormone may send signals to the cancer cells to cause them to grow. (8) Specific medications exist to treat hormone-positive cancers. You will also likely undergo additional testing if you have a hormone-receptor-positive cancer. (9)
Doctors will also give you a test to find out if a gene called HER2 (human epidermal growth factor receptor 2) is involved in your cancer. This gene makes proteins called HER2 receptors, which are involved in managing healthy cell activity. (10)
But one in four breast cancers are HER2-positive, which means the HER2 gene does not work properly and causes cells to grow out of control. Some medications are only used for HER2+ cancer.
Four tests can be used to determine HER2 status:
- IHC test (ImmunoHistoChemistry)
- FISH test (Fluorescence In Situ Hybridization)
- SPoT-Light HER2 CISH test (Subtraction Probe Technology Chromogenic In Situ Hybridization)
- Inform HER2 Dual ISH test (Inform Dual In Situ Hybridization)(10)
If you test negative for both hormone receptors and for HER2, your breast cancer is considered triple negative. An estimated 1 or 2 women of every 10 with breast cancer has triple negative breast cancer. (11)
Anxiety and Stress While Waiting for Results
Undergoing tests can be overwhelming, and you should ask your doctor to provide information on resources for support at the time of your diagnosis. These support resources can be especially helpful in the days and weeks immediately after diagnosis, while you schedule and undergo tests and wait for results.
It is completely normal to feel anxious, worried, and overwhelmed while waiting for test results. (12) One small study even found that the stress of waiting on results from additional testing is similar to the stress of learning you have cancer. (13)
The longer the wait is for the results, the greater the anxiety often can be. (9) Even after a cancer has been treated until no evidence of it exists in your body, many people will still experience bouts of anxiety at times. (14)
You can use a variety of strategies to manage the stress of waiting for test results, from support groups and therapy to meditation and exercise. (15) Several specific relaxation techniques may help as well. (16,15)