Daily clinical practice of fresh tumour tissue freezing and gene expression profiling; logistics pilot study preceding the MINDACT trial

PURPOSE: The 70-gene prognosis-signature is a prognostic tool for early breast cancer analysis. In addition to scientific evidence, implementation of the signature in clinical trials and daily practice requires logistical feasibility. The aim of our study was to test logistics for gene expression profiling on fresh frozen tumour tissue in the preparation for the prospective, multinational Microarray In Node-negative Disease may Avoid ChemoTherapy (MINDACT) trial. METHODS: Sixty-four patients were included in six European hospitals. Fresh frozen tumour samples were shipped on dry ice to Agendia B.V., where RNA was isolated and subsequently hybridised on the 70-gene prognosis-signature (MammaPrint). RESULTS: Tumour samples were obtained in 60 of 64 patients. Among the 60 samples, 11 contained insufficient tumour cells (<50%) and three contained insufficient RNA quality. All 46 samples eligible for genomic profiling were successfully hybridised, and the results were reported on average within 4-5d. CONCLUSION: Gene expression profiling on fresh frozen tissue is feasible in daily clinical practice.