Diagnosing breast cancer involves a variety of tests and exams
If your health care provider thinks you might have breast cancer, you will need certain exams and tests to be sure. Diagnostic procedures for breast cancer may include mammography (imaging of the breast), ultrasound, tumor biopsy, surgery, genetic testing or lab tests (including tests for tumor markers).
Different types of lab tests that can help diagnose breast cancer
Clinical lab testing uses chemical processes to measure levels of chemical components in body fluids and tissues. The most common specimens used in clinical lab tests are blood and urine.
- Blood tests – A variety of blood tests are used to check the levels of substances in the blood that indicate how healthy the body is and whether the infection is present.
- Urinalysis – Urinalysis breaks down the components of urine to check for the presence of drugs, blood, protein, and other substances. Blood in the urine (hematuria) may be the result of a benign (noncancerous) condition, but it can also indicate an infection or other problem.
- Tumor markers – Tumor markers are substances either released by cancer cells into the blood or urine, or substances created by the body in response to cancer cells. Tumor markers are used to evaluate how well a patient has responded to treatment and to check for tumor recurrence. However, not all tumor markers indicate cancer and not every person with cancer has tumor markers.
The following is a brief description of some of the more useful tumor markers for breast cancer:
- CA 125 – Ovarian cancer is the most common cause of elevated CA 125, but cancer of the breast can also raise CA 125 levels. Several noncancerous conditions can also elevate CA 125.
- CA 15-3 – This marker is most useful in evaluating the effect of treatment for women with advanced breast cancer. Elevated levels of CA 15-3 are also associated with noncancerous conditions, such as benign breast or ovarian disease, endometriosis, pelvic inflammatory disease, and hepatitis. Pregnancy and lactation also can raise CA 15-3 levels.
- CA 27-29 – This marker, like CA 15-3, is used to follow the course of treatment in women with advanced breast cancer. Noncancerous conditions associated with this substance are first-trimester pregnancy, endometriosis, ovarian cysts, benign breast disease, kidney disease and liver disease.
Lab test of nipple discharge may reveal cancer cells
Fluid may be collected from nipple discharge and then sent to the lab to look for cancer cells. Most nipple secretions are not cancer. An injury, infection, or benign (non-cancerous) tumor may cause discharge.
When your health care provider has the results of your biopsy and other tests, he or she will contact you with the results. Your provider will talk with you about other tests you may need if breast cancer is found. Make sure you understand the results and what follow-up you need.