Authors concluded that PAM50 Gene Signature was better than Oncotype
DX® and IHC4 Assays at Categorizing Patients
into Low and High Risk for Late Distant Recurrence
Despite recent improvements in breast cancer treatment, some women with ER+ early-stage breast cancer remain at risk of disease recurrence after remaining disease-free for the first five years following diagnosis. Identifying newly diagnosed women with ER+ breast cancer who are at highest risk of having their cancer recur between five and 10 years after diagnosis is a priority for oncologists seeking a tool to help breast cancer patients make more informed treatment decisions.
The goal of this study was to compare the ability of three breast cancer assays to predict risk of distant recurrence separately in years 0 to 5 and years 5 to 10 after diagnosis for postmenopausal women with ER+ early-stage breast cancer. The three breast cancer assays included in the study were the PAM50 gene signature, the Oncotype DX Breast Cancer Assay, and the IHC4 score, derived from immunohistochemical assessment of ER, PR, HER2 and Ki67 genes. The study included 940 samples from the landmark
The researchers concluded that the PAM50 gene signature was the only breast cancer assay of the three evaluated that showed promise in predicting late recurrence and in categorizing patients into low and high risk for late distant recurrence. Although PAM50, Oncotype DX, and IHC4 each added overall prognostic information in the late follow-up period, PAM50 was the best discriminator of patients into low-risk and high-risk groups for late distant recurrence. Of the three assays evaluated, PAM50 provided the strongest risk score in the five to 10 year period for all patient subgroups evaluated in this study.