Interobserver Variability of Gleason Score and Completeness of Histopathology Report in Prostatic Adenocarcinoma in Prostate Needle Biopsy Specimens Among General Pathologists in a Multi-institutional Setting

Introduction. Gleason score, the most widely used grading system for prostatic adenocarcinoma, is the most powerful predictor of patient’s clinical outcome and is used to customize treatment strategies. It possesses an inherent degree of subjectivity, as inter-observer and intra-observer variability does exist. Moreover, there are currently no structured histopathology report guidelines for prostate needle biopsies in our setting, making relevant information overlooked by pathologists and interpretation of report between laboratories challenging. Objective. With these in mind, we sought to study the interobserver variability of Gleason score and completeness of histopathology report in prostate needle biopsy specimens. Methdology. A set of 19 prostate needle biopsy slides was sent to 18 general pathologists from different institutions in the Philippines for histopathologic analysis of Gleason scores and completeness of reporting. The interobserver agreement of each pathologist will be evaluated using Spearman’s rank correlation coefficient. Results. Overall, there was moderate correlation between the interobserver’s Gleason score and Gleason grade group. Low to moderate correlation was seen in primary grade while negligible correlation was seen in secondary grade. Best agreement was seen in poorly differentiated neoplasms. Undergrading was more common than overgrading. Most respondents gave an incomplete histopathology report. Conclusion. There is an overall moderate correlation between Gleason score. A non-standardized histopathology report is currently used, leaving out relevant histopathologic findings.