Nicolas Pennarun1, Yu-Hao Cheng2, Tzu-Ting Huang1, Cheng-Fang Horng1 and Skye Hung-Chun Cheng1,2*
1Department of Medical Research, Koo Foundation Sun Yat-Sen Cancer Center, Taiwan
2Department of Radiation Oncology, Koo Foundation Sun Yat-Sen Cancer Center, Taiwan
Background: There had been several studies using gene-expression profiling in the prediction of distant recurrence in breast cancer. In this study, we developed an 18-gene classifier (18-GC) to predict distant recurrence of breast cancer and compared it in performance with the 21-gene panel (Oncotype DX®, ODx) model.
Method: Included in the study were 224 patients treated for breast cancer with positive hormonal receptor (HR+) and negative human epidermal growth factor receptor 2 (HER2-). We compared the demographic, clinical, and survival information collected from the patients, and further compared the recurrence risk prediction obtained from microarray studies using the 18-GC with that obtained with the 21-gene panel (ODx). To have the best combined sensitivity and specificity, receiver operating characteristics (ROC) curve analysis was performed at the gene level to determine the cutoff values for several breakpoint scores.
Results: For the new 18-GC, a breakpoint score of 21 was adopted to produce a combined highest sensitivity (95 %) and specificity (39%) in detection of distant recurrence. At this breakpoint score, 164 of the 224 patients were classified by the 18-GC in the same risk level as by the 21-gene panel, giving a concordance rate of 73%. Along with patient age and tumor stage, this 18-GC was found to be independent significant prognostic factors of distant metastasis of breast cancer.
Conclusion: We created a new 18-GC for prediction of distant recurrence in HR+ and HER2- breast cancer patients. With a high concordance rate with ODx, the new panel we developed may serve as a good tool for individual breast cancer patients to make an informed decision on whether adjuvant chemotherapy should be performed post-surgery.
Breast cancer; Distant recurrence; Microarray; Gene-expression profiling; Prediction; Chemotherapy
Pennarun N, Cheng Y-H, Huang T-T, Horng C-F, Hung-Chun Cheng S. Gene Expression Profiling in Prediction of Distant Recurrence in HR-Positive and HER2-Negative Breast Cancer Patients. Jpn J Cancer Oncol Res. 2018; 1(1): 1004.