(HealthDay News) — Only 3 percent of women diagnosed with ductal carcinoma in situ (DCIS) will die of breast cancer within 20 years, and more aggressive treatment does not improve that high survival rate, according to a study published online Aug. 20 in JAMA Oncology.
Steven Narod, M.D., director of the Familial Breast Cancer Research Unit at the Women’s College Research Institute in Toronto, and colleagues reviewed data for 108,196 women who had been diagnosed with DCIS between 1988 and 2011. The authors compared these patients’ risk of dying from breast cancer with the risk for women in the general population. On average, the women were 54 years of age when they received their DCIS diagnosis, and the authors followed their outcomes for an average of 7.5 years. The team then estimated overall mortality rates at 10 and 20 years.
In all, 956 women in the study ultimately died of breast cancer. Of those, 517 never had invasive cancer in the breast after successful treatment for DCIS. The study authors also found that women with a history of DCIS had about the same rates of invasive breast cancer in either breast, not just the breast where the DCIS was detected. The researchers also found that addition of radiation therapy did not appear to reduce mortality compared to just surgery alone.
The mortality rates for both younger women and black patients diagnosed were higher, the researchers noted. Narod told HealthDay that for populations with the highest risk, at some point, chemotherapy might become an option to deal with DCIS cells that may be lingering outside the treated breast.