DCIS is the pre-invasive form of Breast Cancer, which has been diagnosed in increasing numbers due to screening mammograms. It is confined to the inside of the ductal lining, and has no access to the lymphatics and blood vessels that drain away from the breast, so it cannot travel outside of the breast. It requires complete removal, and patients are offered radiation therapy after the lumpectomy, and Tamoxifen for 5 years, as a risk reduction strategy. However, absolute numbers of recurrences are small, probably mostly colored by the fact that most DCIS is of low risk. Till now, there was no quantitative way of differentiating risk, and we probably have over-treated most women with DCIS.

This year, the results of study were presented at the San Antonio Breast Conference, which will help assign risk, and mitigating treatment.

The Oncotype Dx DCIS test is a 12 gene assay that is performed on the cancer tissue. It was recently presented as a recurrence risk predictor for DCIS , an early, non invasive form of Breast Cancer. Its is an offshoot of the 21 gene Oncotype Dx recurrence score for invasive breast cancer. It is scored from 0-100, < 39 is low risk, 39-54 is intermediate risk, and > 54 is high risk. 75 % of the patients studied were in the low recurrence score, and this will be helpful in eliminating the need for treatment in the low risk category.