The Genomic Grade (GG) assay can refine the prediction of risk of distant recurrence and identify a larger proportion of patients who had excellent distant recurrence-free interval (DRFI) at 10 years with just 5 years of endocrine therapy compared with centrally reviewed immunohistochemical testing of Ki67 and HG. This according to a phase 3 adjuvant trial and 883 breast cancer samples. Researchers determined:
• Either increasing GG or Ki67 was significantly associated with lower distant relapse free intervals and added independent prognostic information to standard clinicopathological factors.
• In node-negative, endocrine-only patients, low GG assay results were associated with a 10-year distant relapse-free interval of 99%.
• The GG assay can be used to identify patients with early breast cancer who have excellent prognosis for endocrine therapy only.
Citation: Ignatiadis M, Azim HA, Desmedt C, et al. The genomic grade assay compared with Ki67 to determine risk of distant breast cancer recurrence. [Published online ahead of print December 3, 2015]. JAMA Oncol. doi: 10.1001/jamaoncol.2015.4377.