TY - JOUR T1 - Recommendations for standardizing biopsy acquisition and histological assessment of immune checkpoint inhibitor-associated colitis JF - Journal for ImmunoTherapy of Cancer JO - J Immunother Cancer DO - 10.1136/jitc-2022-004560 VL - 10 IS - 3 SP - e004560 AU - Christopher Ma AU - Rish K Pai AU - David F Schaeffer AU - Jonathan Krell AU - Leonardo Guizzetti AU - Stefanie C McFarlane AU - John K MacDonald AU - Won-Tak Choi AU - Roger M Feakins AU - Richard Kirsch AU - Gregory Y Lauwers AU - Reetesh K Pai AU - Christophe Rosty AU - Amitabh Srivastava AU - Joanna C. Walsh AU - Brian G Feagan AU - Vipul Jairath Y1 - 2022/03/01 UR - http://jitc.bmj.com/content/10/3/e004560.abstract N2 - Immune checkpoint inhibitor-associated colitis (ICIC) affects approximately 15% of cancer patients treated with immunotherapy. Although histological evaluation is potentially valuable for both the diagnosis of ICIC and evaluation of disease activity, use in clinical practice is heterogeneous. We aimed to develop expert recommendations to standardize histological assessment of disease activity in patients with ICIC. Using the modified Research and Development/University of California Los Angeles (RAND/UCLA) appropriateness methodology, an international panel of 11 pathologists rated the appropriateness of 99 statements on a 9-point Likert scale during two rounds of anonymous voting. Results were discussed between rounds using moderated videoconferences. There are currently no disease-specific instruments for assessing histological features of ICIC. The panel considered that colonoscopy with at least three biopsies per segment from a total of at least five segments, including both endoscopically normal and inflamed areas, was appropriate for tissue acquisition. They agreed that biopsies should be oriented such that the long axis of the colonic crypts is visualized and should be stained with hematoxylin and eosin. Histological items that the panel voted were appropriate to evaluate in ICIC included the degree of structural/architectural change, chronic inflammatory infiltrate, lamina propria and intraepithelial neutrophils, crypt abscesses and destruction, erosions/ulcerations, apoptosis, surface intraepithelial lymphocytosis, and subepithelial collagen thickness. The appropriateness of routine immunohistochemistry was uncertain. These expert recommendations will help standardize assessment of histological activity in patients with ICIC. The panel also identified the development and validation of an ICIC-specific histological index as a research priority. ER -