INTER-OBSERVER VARIATION IN THE HISTOLOGICAL DIAGNOSIS OF POLYPS IN COLORECTAL CANCER SCREENING

Paul G van Putten (1) , Lieke Hol (1) , Herman van Dekken (2) , Han van Krieken (3) , Marjolein van Ballegooijen (4) , Ernst J Kuipers (1, 5) , Monique E van Leerdam (1)

1 Department of Gastroenterology and Hepatology
2 Department of Pathology
3 Department of Pathology
4 Department of Public Health
5 Department of Internal Medicine

Aim: To determine the inter-observer variation in the histological diagnosis of colorectal polyps. Methods and results: 440 polyps were randomly selected from a colorectal cancer (CRC) screening program. Polyps were first evaluated by a general (324 polyps) or expert (116 polyps) pathologist, and subsequently re-evaluated by an expert pathologist. Conditional agreement was reported and inter-observer agreement was determined by using Kappa statistics. In 421/440 polyps (96%) agreement for the non-adenomatous or adenomatous nature was obtained, corresponding with a very good kappa of 0.88. Differentiating adenomas as non-advanced and advanced obtained consensus in 266/322 adenomas (83%), with a moderate kappa of 0.58. For the non-adenomatous or adenomatous nature, both general and expert pathologists, and expert pathologists among each other, showed very good agreement (kappa-values (95%CI); 0.89(0.83-0.95) and 0.86(0.73-0.98), respectively). Categorizing adenomas as non-advanced and advanced showed moderate agreement between general and expert pathologists, and between expert pathologists (kappa-values (95%CI); 0.56(0.44-0.67) and 0.64(0.43-0.85), respectively). Conclusions: General and expert pathologists demonstrate very good inter-observer agreement for differentiating non-adenomas from adenomas, but only moderate agreement for non-advanced and advanced adenomas. The considerable variation in the interpretation of advanced histology suggests that more objective criteria are required for risk stratification in screening and surveillance guidelines.

Mots clés: Medicine

Paul G van Putten, Lieke Hol, Herman van Dekken, Han van Krieken, Marjolein van Ballegooijen, et al.. INTER-OBSERVER VARIATION IN THE HISTOLOGICAL DIAGNOSIS OF POLYPS IN COLORECTAL CANCER SCREENING. Histopathology, 2011, 58 (6), pp.974. ⟨10.1111/j.1365-2559.2011.03822.x⟩. ⟨hal-00642394⟩