Gene Expression Profiling and its Utility in Prediction of Local Relapse after Breast-conserving Therapy in Early Breast Cancer

摘要

Background: Local relapse (LR) after breast-conserving therapy (BCT) is not accurately predicted by histological/clinical factors. Gene expression profiling was used here to discover LR-associated transcriptional alterations. Materials and Methods: Gene expression profiling was carried out of 81 early breast carcinomas obtained from 30 patients who developed a LR (LR+) after BCT and 51 who did not (LR-). LR+ and LR- samples were matched for known LR risk features. Results: LR was not associated with a given molecular subtype. Supervised analysis identified a 212-gene signature, which was not validated in independent tumors. No gene set or biological pathway was differentially expressed between LR+ and LR- groups. Twelve published prognostic expression signatures failed to distinguish these groups of carcinomas. The gene expression profiles of 9 cases of LR and the corresponding primary tumors were very similar despite the delivery of radiotherapy. Conclusion: In this series, the onset of LR was not predicted by gene expression alterations.