Study Examines Breast Cancer Mortality After DCIS Diagnosis
Researchers estimate the 20-year breast cancer-specific death rate for women diagnosed with ductal carcinoma in situ to be 3.3 percent, although the death rate is higher for women diagnosed before age 35 and for black women, according to an article published in the journal JAMA Oncology.
Ductal carcinoma in situ breast (DCIS) cancer, which is also referred to as stage 0 breast cancer, accounts for about 20 percent of the breast cancers detected through mammography. Some women with DCIS experience a second breast cancer (DCIS or invasive) and a small proportion of patients with DCIS ultimately die of breast cancer. However, it is not clear what factors might predict mortality after a DCIS diagnosis. Women who develop an invasive breast cancer on the same side of the body have an increased risk of death but some women die without first receiving a diagnosis of local invasive disease.
Steven A. Narod, M.D., F.R.C.P.C., of the Women's College Hospital, Toronto, and coauthors used the Surveillance, Epidemiology and End Results (SEER) 18 registries database to study women diagnosed with DCIS from 1988 to 2011. The study ultimately included 108,196 women whose risk of dying of breast cancer was compared with that of women in the general population. The average age at diagnosis for women was nearly 54 and the average duration of follow-up was 7.5 years.
The authors estimated the 10-year breast cancer-specific death rate after DCIS diagnosis to be 1.1 percent and the rate at 20 years to be 3.3 percent. Compared with women in the general population, the risk of dying of breast cancer for a women who had a DCIS diagnosis was 1.8 times higher, according to the results.