Reproducibility of Gleason grading of prostate cancer can be improved by the use of reference images

摘要: Objectives. The Gleason system has become the international standard for grading prostate cancer. Its interobserver reproducibility is fairly good but needs improvement. A national effort to standardize in Sweden was evaluated. Methods. teaching set of 40 images illustrating grades distributed 85 Swedish pathologists, including 73 specialists and 12 residents. Their ability assign correct (1 5) a series microphotographs tested before after distribution set. Each test included 20 images, graded by an expert panel. Results. proportion improved from 70.5% first 86.6% second (P <0.001). Undergrading decreased 22.5% 9.4%. Grading errors more than one step were uncommon 1 (1.9%) almost disappeared 2 (0.1%). average kappa value tests 0.58 0.78, respectively. Conclusions. results this study reveal that reference may significantly improve grading. This method inexpensive based on modern imaging techniques. can be easily large number either as paper copies or through Internet (http://www.pathology.ks.se/egevad/gleason.html), can, thereby, readily available everyday practice.