CHICAGO (AP) — New research finds that chances of dying from very early breast cancer are small but the disease is riskier for young women and blacks. Those disparities have been seen previously in more advanced cancer.

Death rates 20 years after diagnosis totaled about 3 percent for women whose breast cancer was confined to a milk duct. The death rates were twice as high for those younger than 35 and in blacks — but still lower than those with more common invasive breast cancer.

The findings will likely add to the debate over how to treat these early kinds of tumors.

Researchers analyzed government data on more than 100,000 women diagnosed with DCIS — ductal carcinoma in situ.

The study was published Thursday in the journal JAMA Oncology.