Predicting breast cancer recurrence using a genetic test

This study investigated the efficacy of using the ductal carcinoma in situ (DCIS) score to predict the risk of recurrence (return of the cancer) in patients with DCIS.

Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside the milk ducts (vessels) of the breast. In DCIS these abnormal cells are confined to the milk ducts, but this is considered the initial stage of cancer formation. Therefore, these cells must be removed by surgery. After surgical removal of DCIS, recurrence of this abnormal growth in the same breast is a concern. This recurrence is called an ipsilateral breast event (IBE). Additional treatments after surgery, like radiation therapy or hormonal therapy, have been shown to reduce the risk of recurrence in DCIS patients.

The DCIS score (also known as the Oncotype DX test) provides information about the likelihood of IBE. It involves the examination of a sample from the cancer cells to check their genetic makeup. Patients with lower DCIS score results have a lower risk of breast cancer recurrence.

A total of 327 patients were involved in this study and were followed up for ten years. Patients were divided by their DCIS scores into low, intermediate and high risk groups. After 10 years, 10.6% of the patients in the low-risk group developed an IBE, compared to 26.7% in the intermediate-risk group, and 25.9% in the high-risk group. The 10-year rates of invasive IBE (recurrence of a cancer that has spread beyond the milk ducts) were 3.7% in the low-risk group, 12.3% in the intermittent-risk group, and 19.2% in the high-risk group.

In summary, the DCIS Score was an efficient test for predicting the risk of DCIS recurrence.

Consult with your physician about genetic testing and the risk of DCIS recurrence when choosing a treatment plan.