Radiotherapy Benefit in High-Risk Patients Classified by an 18-Gene Panel

Jian Liu, Yu-Hao Cheng, Weiwei Huang, Fan Wu, Jason Lei and Hung-Chun S. Cheng

Department of Medical Oncology, Fujian Cancer Hospital, Fujian Medical University Cancer Hospital, China
Department of Medicine, Cathay General Hospital, Taipei, Taiwan
Department of Research and Development, Amwise Diagnostics Pte Ltd, Singapore
Department of Radiation Oncology, Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan

^*Correspondance to: Hung-Chun S. Cheng 

 PDF  Full Text DOI: 10.25107/2474-1647.2215

Abstract

Purpose: An 18-gene classifier (18-GC) was developed to identify breast cancer patients of low- and high-risk in any recurrence. However, the benefit of adjuvant radiotherapy for high-risk patients identified by the 18-GC is still unclear. This study was therefore performed to explore if these highrisk patient would benefit from adjuvant radiotherapy.Methods: Two hundred and thirteen patients with operable breast cancer were enrolled in the study. Propensity score analysis was conducted with ratio of 2:1 to match patients with (n=142) or without (n=71) adjuvant radiotherapy by age, T stage, N stage, tumor grade and ER status. We use pre-defined 18-gene scoring algorithm to define scores ≥ 21 and ≥ 44 as the high-risk group of Distant Recurrence (DR) and Local/Regional Recurrence (LRR), respectively. The primary outcome is 5-years Relapse Free Survival (RFS) rate.Results: Forty two of the 213 patients had an 18-GC risk score lower than 21 (low DR risk) whereas the remaining 171 had a score greater or equal to 21 (high DR risk). The low- and high-risk group had an RFS at 96.8% and 77.4%, respectively. The radiotherapy treatment and the high DR risk score was found to have a statistically significant interaction (P=0.0122). The 114 and 57 patients treated and untreated with radiotherapy had a 5-yr RFS at 85.7% and 61.3%, respectively (P=0.0008).Conclusion: The 18-GC can predict both the extent of radiotherapy benefit and the risk of recurrence of breast cancer.

Keywords

Breast cancer; Recurrence, Prognosis; Microarray gene-expression profiling; Radiotherapy benefit

Cite the article

Liu J, Cheng Y-H, Huang W, Wu F, Lei J, Cheng H-C S. Radiotherapy Benefit in High-Risk Patients Classified by an 18-Gene Panel. Clin Surg. 2018; 3: 2215.