Interobserver agreement in grading of colorectal cancers-findings from a nationwide web-based survey of histopathologists.

Abstract

Tumour grade represents a gestalt of all molecular changes in malignancy, reflecting aggressiveness and has been shown to add prognostic information independent of stage for many malignancies, including colorectal cancer. Despite the grade of colorectal cancer being reported routinely in the UK, there is paucity of data on the level of agreement between histopathologists and hence the value of this metric in clinical practice. The aim was to estimate the degree of inter-observer variation in grading by conducting a nationwide web-based survey of histopathologists.