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Dividing to Conquer Breast Cancer
Since 2010, cancer registries have been required to report both HR and HER2 status, allowing researchers to more accurately stratify breast cancer...
According to a study published today in JAMA Oncology, a diagnosis of ductal carcinoma in situ (DCIS)—or stage 0 breast cancer—may not be reason enough for treatment.
Researchers conducted a multivariate analysis of 108,196 women, whose data were pulled from the Surveillance, Epidemiology, and End Results (SEER) 18 registries database. The primary outcome of the study was 10- and 20-year cancer-specific mortality. The results showed that age at diagnosis and ethnicity were significant predictors of breast cancer mortality: Women diagnosed before age 35 had a higher risk of death from breast cancer at 20 years than did older women (7.8% vs 3.2%; hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.85-3.60; P < .001), and black women had a higher risk of death from DCIS than did white, non-Hispanic women (7.0% vs 3.0%; adjusted HR, 2.42, 95% CI, 2.05-2.87; P < .001).
Related: Dividing to Conquer Breast Cancer
In addition, the article notes that the finding of greatest clinical importance was that prevention of ipsilateral invasive recurrence did not prevent death from breast cancer. Women diagnosed with DCIS who developed an ipsilateral invasive in-breast recurrence were 18.1 times more likely to die of breast cancer than were women who did not; however, after adjustment for tumor size, grade, and other factors, the difference in survival for mastectomy vs lumpectomy was not significant (HR, 1.20; 95% CI, 0.96-1.50; P = .11).
Patients with breast cancer often undergo the Oncotype DX breast cancer assay to identify those who are at low risk for death from breast cancer and who might not benefit from chemotherapy. However, the researchers of the current study propose that the test be used instead to identify patients who are at high risk for invasive recurrence.
Related: Advances in Targeted Therapy for Breast Cancer
The 10-year mortality rate assessed in this study continues a downward trend established in previous studies, but “it is unlikely that the decline in mortality [for women who received a diagnosis of ductal carcinoma in situ between 1998 and 2011] is due to more effective treatments,” the authors note, “because we show here that mortality rates did not vary with specific treatment.”
View on the News: Reboot needed on DCIS treatment
Source
Narod SA, Iqbal J, Giannakeas V, Sopik V, Sun P. JAMA Oncol. [Published online ahead of print August 20, 2015.]
doi: 10.1001/jamaoncol.2015.2510.
