70-gene Signature May Inform Treatment Decisions for Breast Cancer
Findings of a lower 5-year survival rate without distant metastasis suggest that ~46% of patients clinically high-risk breast cancer may not require chemotherapy.
For women with early-stage breast cancer who were determined to be at high clinical risk and low genomic risk for recurrence, not receiving chemotherapy led to a lower rate of 5-year survival without distant metastases, in contrast with those who did receive chemotherapy, according to a study published in The New England Journal of Medicine.1 These findings suggest that, in patients with clinically high-risk breast cancer, about 46% may not require chemotherapy.
Researchers conducted a randomized phase 3 study and identified 1550 patients with high clinical risk and low genomic risk, using a modified version of Adjuvant! Online and the 70-gene signature test (MammaPrint), respectively.
The study's aim was to determine if the lower boundary of the 95% confidence interval for 5-year survival rate without distant metastases would be at least 92% among patients who did not receive chemotherapy and had high-risk clinical features and a low-risk gene-expression profile.
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The rate of survival without distant metastases among these patients was 94.7% at 5 years for those who did not receive chemotherapy. There was an absolute difference in survival of 1.5 percentage points when comparing those who did and those who did not receive chemotherapy, with a lower rate in the group that did not receive chemotherapy.
Similar rates of survival without distant metastases were found among patients who had estrogen-receptor-positive, human epidermal growth factor receptor 2-negative disease, and both node-negative or node-positive disease.
Editor's Note: The original version of this article has been edited to reflect that the findings from the study indicate that certain patients with breast cancer may not require chemotherapy. In addition, the author incorrectly referred to the type of risk that the 70-gene signature test (MammaPrint) identifies; this test is a tool to assess for genomic risk.
- Cardoso F, van't Veer LJ, Bogaerts J, et al. 70-Gene signature as an aid to treatment decisions in early-stage breast cancer. NEJM. 2016 Aug 25. doi: 10.1056/NEJMoa1602253 [Epub ahead of print]