21-gene Recurrence Score Predicts Survival in Stage 4 Breast Cancer

The 21-gene Recurrence Score is independently associated with both time to first progression and 2-year overall survival in patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative de novo stage 4 breast cancer, a study published in the Journal of Clinical Oncology has shown.¹

The 21-gene Recurrence Score assay analyzes the activity of 21 genes to determine the risk for breast cancer recurrence, the likelihood of benefit of chemotherapy from early-stage invasive disease, and the likelihood of benefit from radiotherapy for ductal carcinoma in situ.

For this study, researchers sought to determine whether the assay provides clinically meaningful information in patients with de novo stage 4 breast cancer.

Researchers analyzed data from 109 patients from 14 sites enrolled in the Translational Breast Cancer Research Consortium (TBCRC) 013, a multicenter prospective registry that assessed the role of surgery of the primary tumor. Of those, 66% had hormone receptor (HR)-positive, HER2-negative disease and 18% had HR-positive, HER2-positive cancer.

Results showed that at a median follow-up of 29 months, median time to first progression was 20 months (95% CI: 16-26) and median overall survival was 49 months (95% CI: 40-not reached).

Using the Recurrence Score, 22 patients were classified as low risk (<18), 29 as intermediate risk (18 to 30), and 50 as high risk (≥31). Researchers found that the 21-gene Recurrence Score was associated with time to first progression (P=.01) and 2-year overall survival (P=.04).

After adjusting for confounding factors, the study demonstrated that the Recurrence Score was independently prognostic for time to first progression (HR, 1.40; 95% CI: 1.05-1.86; P=.02) and 2-year overall survival (HR, 1.83; 95% CI: 1.14-2.95; P=.013) among the 69 patients with ER-positive, HER2-negative breast cancer.

The authors note that these findings need to be validated in a prospective trial to determine the potential role for this assay in the clinical management of this particular patient population.

Reference

1. King TA, Lyman JP, Gonen M, et al. Prognostic impact of 21-gene Recurrence Score in patients with stage IV breast cancer: TBCRC 013 [published online ahead of print March 21, 2016]. J Clin Oncol. doi: 10.1200/JCO.2015.63.1960.