Molecular Lymph Node Staging with One-Step Nucleic Acid Amplification in Colon Cancer and its Prognostic Value

One-step nucleic acid amplification (OSNA) was introduced as a method to detect tumor specific mRNA in sentinel lymph nodes (SLN) of patients undergoing surgery for breast cancer [1]. With OSNA, cytokeratin 19 (CK19) mRNA is amplified based on reverse transcription-loopmediated isothermal amplification and a threshold of ≥ 250 mRNA copies /μL is considered as a positive lymph node [2]. In the evaluation of SLN from patients with breast cancer OSNA shows a sensitivity of 87.5-100% and a specificity of 90.5-100% [3,4]. Molecular lymph node work-up with OSNA is nowadays a validated diagnostic and prognostic adjunct in breast cancer surgery [5]. Therefore, its diagnostic and prognostic capabilities seemed to be promising for the staging of colon cancer.