Interobserver variability in assessing dysplasia and architecture in colorectal adenomas: a multicentre Canadian study.

AIMS: Following the introduction of colorectal cancer screening programmes throughout Canada, it became necessary to standardise the diagnosis of colorectal adenomas. Canadian guidelines for standardised reporting of adenomas were developed in 2011. The aims of the present study were (a) to assess interobserver variability in the classification of dysplasia and architecture in adenomas and (b) to determine if interobserver variability could be improved by the adoption of criteria specified in the national guidelines. METHODS: An a priori power analysis was used to determine an adequate number of cases and participants. Twelve pathologists independently classified 40 whole-slide images of adenomas according to architecture and dysplasia grade. Following a wash-out period, participants were provided with the national guidelines and asked to reclassify the study set. RESULTS: At baseline, there was moderate interobserver agreement for architecture (K=0.4700; 95% CI 0.4427 to 0.4972) and dysplasia grade (K=0.5680; 95% CI 0.5299 to 0.6062). Following distribution of the guidelines, there was improved interobserver agreement in assessing architecture (K=0.5403; 95% CI 0.5133 to 0.5674)). For dysplasia grade, overall interobserver agreement remained moderate but decreased significantly (K=0.4833; 95% CI 0.4452 to 0.5215). Half of the cases contained high-grade dysplasia (HGD). Two pathologists diagnosed HGD in ≥75% of cases. CONCLUSIONS: The improvement in interobserver agreement in classifying adenoma architecture suggests that national guidelines can be useful in disseminating knowledge, however, the variability in the diagnosis of HGD, even following guideline review suggests the need for ongoing knowledge-transfer exercises.

Prostate gland biopsies and prostatectomies: an Ontario community hospital experience.

OBJECTIVE: Transrectal ultrasound-guided core biopsies of the prostate gland and prostatectomies have become common procedures at many community hospitals in Canada, especially in the era of serum prostate-specific antigen (PSA) screening for prostate cancer. The Gleason grading of prostate cancer in biopsies and prostatectomies is a major determinant used for treatment planning. There is evidence in the literature that suggests important discordance between community hospital pathologists and urological pathologists with respect to the Gleason grading of prostate cancer. Our objective was to determine the diagnostic rates and Gleason scoring patterns for prostate gland biopsies and prostatectomies at our institution compared with the literature. METHODS: We conducted a retrospective review of all prostate gland biopsies and prostatectomies performed at the Grey Bruce Health Services from January 2005 to September 2005. We collected data from 194 biopsies and 44 prostatectomies. We obtained prebiopsy serum PSA levels and digital rectal exam results for all patients from urologists' office records. RESULTS: The average age for men having biopsies was 65.8 (standard deviation [SD] 8.6) years, and the average prebiopsy serum PSA level was 8.7 (median 7.1, SD 6.2) mug/L. The rates of diagnosis from prostate gland biopsies of benign (17.6%), high-grade prostatic intraepithelial neoplasia (11.0%), atypical small acinar proliferation suspicious for invasive malignancy (13.2%) and invasive prostatic adenocarcinoma (58.2%) at our institution were significantly different than those reported in the literature (p < 0.001). We observed a significant variation in the rates of these diagnoses among the community hospital pathologists in our study (p = 0.004). There was a strong correlation between the increasing number of positive core biopsy sites and increasing Gleason scores in biopsies (p < 0.001). There was also a strong correlation between increasing pre-biopsy serum PSA levels and increasing Gleason scores in biopsies (p < 0.001). A substantial proportion (21.9%) of the biopsies given the Gleason score of 6 had a Gleason score of 7 in the prostatectomy specimen. CONCLUSION: Our results showed a significant difference in prostate gland biopsy categorical diagnoses compared with the literature. There were also significant differences in categorical diagnoses of prostate gland biopsies among the community hospital pathologists in our study. The data identify a strong positive correlation between the increasing number of positive core biopsy sites and increasing Gleason scores in biopsies, as well as a strong positive correlation between increasing prebiopsy serum PSA levels and increasing Gleason scores in biopsies that revealed cancer. We would encourage other community hospital pathologists, in collaboration with their urologists, to review periodically their prostate gland pathology practices in an attempt to improve the uniformity of diagnoses.