The United States Food and Drug Administration (FDA) has recently approved the TOP2A FISH pharmDx test, a genetic test to help assess risk of breast cancer recurrence and long-term survival for early breast cancer patients. The TOP2A FISH pharmDx test is approved for breast cancer patients who are considered to have a moderate to high risk of developing a recurrence.
Each year breast cancer is diagnosed in more than 178,000 women in the United States alone. Following diagnosis, various tests are performed to further describe characteristics of the cancer as well as the extent of spread of the cancer. These findings are used to help individualize therapy and determine optimal treatment options for every patient.
Clinical research in genetics is revealing more about causes of breast cancer and the roles that genetics plays in its development. In some cases, genetics also may be used to predict a patient’s response to specific therapies.
One gene that appears to play an important role in response to therapies and outcomes for patients with breast cancer is the TOP2A gene, which is involved in cellular replication. Mutations (alterations) in the TOP2A gene strongly predict responses to a group of chemotherapy agents referred to as anthracyclines (Adriamycin® [doxorubicin] and Ellence® [epirubicin]). As well, mutations-specifically overexpression of TOP2A-predict an increase in breast cancer recurrence as well as decreased survival.
The TOP2A FISH pharmDx is the first approved test to detect overexpression of the TOP2A gene in cancer patients. The test is performed on breast cancer cells that have been taken from the breast during surgical removal of the cancer. The TOP2A test was approved based on results from a Danish study that included 767 patients with early breast cancer who were considered at high risk of a cancer recurrence.
Overall, results from the TOP2A FISH pharmDX test accurately estimated the time to breast cancer recurrence and overall survival for women diagnosed with high-risk breast cancer who were undergoing treatment with certain chemotherapy regimens. Further studies are necessary to determine the effectiveness of TOP2A FISH pharmDX in predicting prognosis for patients undergoing specific treatment regimens.
Patients with early breast cancer are encouraged to speak to their physician regarding the TOP2A FISH pharmDX test and other testing options.