The aims of this preliminary study were to evaluate the association between the Oncotype DX (ODX) recurrence scores and traditional prognostic factors and to develop a nomogram that predict a subgroup of patients with low ODX recurrence scores (≤25), in whom addition of chemotherapy can be avoided.
Clinicopathological and immunohistochemical variables from a series of 396 T1-3N0-1miM0 hormone receptor-positive, human epidermal growth factor-2 (HER2)-negative breast cancer patients with available ODX test results at Asan Medical Center from 2010 to 2015 were retrospectively retrieved and analyzed. One hundred eight (27%) had positive axillary lymph node micrometastases, and 333 (84%) had ODX recurrence scores of ≤25. Logistic regression was performed to build a nomogram for predicting a low-risk subgroup of the ODX assay. The cutoff value of ODX recurrence scores for the low-risk subgroup was set at 25, which is used in the ongoing Oncotype DX phase 3 TAILORx trial.
Multivariate analysis revealed that estrogen receptor (ER) score, progesterone receptor (PR) score, lymphovascular invasion (LVI), nuclear grade, and Ki-67 had statistically significant association with the low-risk subgroup (all p values
Low ODX recurrence score subgroup can be predicted by a nomogram incorporating five traditional prognostic factors: ER, PR, LVI, nuclear grade, and Ki-67. An independent prospective validation for the present nomogram is underway to confirm its accuracy.
Clinical trial identification
This is not the clinical trial.
Legal entity responsible for the study
Asan Medical Center
All authors have declared no conflicts of interest.