The urokinase plasminogen activator and its inhibitor are proteins found on the outside of breast cancer tumor cells that help the cancer grow and spread. Higher levels of these proteins have been linked to worse outcomes.
Testing for these two proteins is done on breast cancer tissue removed during biopsy or surgery.
Test results are reported as a score:
- 0.0-0.4 is normal
- 0.41-2.8 is borderline
- 2.81-5.7 is high
Doctors may test for levels of the urokinase plasminogen activator protein and its inhibitor protein in women diagnosed with hormone-receptor-positive, HER2-negative breast cancers that have not spread to the lymph nodes (node-negative cancer).
In many cases, cancers with these characteristics are considered to have a low risk of recurrence (the cancer coming back). Knowing the levels of these two proteins can help women and their doctors decide whether chemotherapy or other treatments are needed after surgery.