One Step Nucleic Acid amplification testing for CK19 : single copy number >5,000 copies/μL vs Total Tumour Load of 15,000 copies/μL

Abstract

Background: The diagnostic criteria for OSNA proposes cut-off values of >5000 copies/μL of CK 19 mRNA as macro-metastases. Practice in our centre is to perform axillary node clearance (ANC) on patients with a copy number of >5000 in any node. A recent study has suggested an alternative method using the total copy number of all sentinel nodes (Total Tumour Load) with a cut-off of 15,000 copies/μL.