TY - JOUR T1 - OSNA testing for lymph node staging in colorectal cancer JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 638 LP - 639 DO - 10.1136/jclinpath-2016-204299 VL - 70 IS - 7 AU - Richard Colling AU - Trevor Yeung AU - Roel Hompes AU - Rebecca Kraus AU - Ronan Cahill AU - Neil Mortensen AU - Lai Mun Wang Y1 - 2017/07/01 UR - http://jcp.bmj.com/content/70/7/638.abstract N2 - Lymph node staging in colorectal cancer (CRC) is established by histological examination. Molecular techniques, such as one-step nucleic acid amplification (OSNA), have been recommended by NICE1 for intraoperative sentinel node assessment in breast cancer. OSNA is a relatively novel and simple molecular technique that uses a reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) reaction to detect tumour specific (CK19) mRNA in lymph nodes. We aim to provide unbiased data on the diagnostic accuracy of OSNA in detecting CRC nodal metastases and feedback the practicalities of running such a service in an National Health Service (NHS) cellular pathology department.Consent was sought from consecutive patients undergoing elective resection for any stage CRC over a 14-month period (November 2013–December 2014). Stented tumours and perforated cases were excluded.Resected specimens were received fresh, inked according to standard guidelines and lymph nodes were dissected. Each harvested node was bisected—one half was fixed in 10% formalin for routine histology and the other was snap-frozen in liquid nitrogen and stored at −80°C for OSNA processing. The remaining specimen was fixed and subsequently dissected for standard histology. OSNA assaying was performed as per manufacturers' instructions. Lymph nodes weighing >0.05 g were analysed in a single assay and those <0.05 g were combined for processing. Nodes were homogenised in lysis buffer (Lynorhag; Sysmex) and … ER -