Prediction of Oncotype DX Recurrence Score Using Clinicopathological Variables in Estrogen Receptor-Positive/ Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer
- Author:
Min Chong KIM
1
;
Sun Young KWON
;
Jung Eun CHOI
;
Su Hwan KANG
;
Young Kyung BAE
Author Information
- Publication Type:Original Article
- From:Journal of Breast Cancer 2023;26(2):105-116
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:Oncotype DX (ODX) is a well-validated multigene assay that is increasingly used in Korean clinical practice. This study aimed to develop a clinicopathological prediction (CPP) model for the ODX recurrence scores (RSs).
Methods:A total of 297 patients (study group, n = 175; external validation group, n = 122) with estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, T1-3N0-1M0 breast cancer, and available ODX test results were included in the study. Risk categorization as determined by ODX RSs concurred with the TAILORx study (low-risk, RS ≤ 25; high-risk, RS > 25). Univariate and multivariate logistic regression analyses were used to assess the relationships between clinicopathological variables and risk stratified by the ODX RSs. A CPP model was constructed based on regression coefficients (β values) for clinicopathological variables significant by multivariate regression analysis.
Results:Progesterone receptor (PR) negativity, high Ki-67 index, and nuclear grade (NG) 3 independently predicted high-risk RS, and these variables were used to construct the CPP model. The C-index, which represented the discriminatory ability of our CPP model for predicting a high-risk RS, was 0.915 (95% confidence interval [CI], 0.859–0.971). When the CPP model was applied to the external validation group, the C-index was 0.926 (95% CI, 0.873–0.978).
Conclusion:Our CPP model based on PR, Ki-67 index, and NG could aid in the selection of patients with breast cancer requiring an ODX test.
