Age at diagnosis and black ethnicity are important risk factors for death from breast cancer following ductal carcinoma in situ (DCIS) diagnosis, according to a recent study published online ahead of print in JAMA Oncology.
In addition, risk of death increases upon diagnosis of an ipsilateral second primary invasive breast cancer, and prevention of recurrence by radiotherapy may not diminish mortality at 10 years in these patients.
In an observational study, researchers led by Steven Narod, MD, FRCPC, of the Women’s College Hospital in Toronto, Canada, looked at 108,196 women diagnosed with DCIS from 1988 to 2011 through the SEER registries database in order to estimate 10- and 20-year mortality and to determine whether it would be influenced by diagnosis, ethnicity, and initial treatment.
Risk for death in patients observed was compared with the general population, with Cox proportional hazard analysis performed to estimate hazard ratio for death from DCIS by age at diagnosis, clinical features, ethnicity, and treatment option.
The researchers found that breast cancer-specific mortality was higher for women who received diagnoses before 35 years compared to older women, as well as blacks compared to non-Hispanic whites. Risk of dying of breast cancer increased in patients who experienced ipsilateral invasive breast cancer.
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In total, 517 patients had died of breast cancer following DCIS diagnoses without experiencing in-breast invasive cancer prior to death. In patients who underwent lumpectomy, radiotherapy was associated with a lower risk of ipsilateral invasive recurrence but not breast cancer-specific mortality at 10 years.
- Narod SA, Iqbal J, Giannakeas V, et al. Breast cancer mortality after a diagnosis of ductal carcinoma in situ. JAMA Oncology. 2015. [epub ahead of print]. doi:10.1001/jamaoncol.2015.2510.