Objectives To assess the incidence of biopsy-verified coeliac disease (CD) in Sweden and examine the incidence of duodenal/jejunal biopsies with normal mucosa over time as a proxy for CD awareness and investigation. Design Nationwide population-based cohort study 1990–2015 based on biopsy reports indicating villous atrophy (VA) or normal mucosa in the duodenum/jejunum. Results We identified 44 771 individuals (63% females) with a biopsy report specifying VA and 412 279 (62% females) with a biopsy report indicating normal mucosa (without a prior biopsy indicating VA). The median age at diagnosis of CD was 28 years. The mean age-standardised incidence rate during the study period was 19.0 per 100 000 person-years (95% CI 17.3 to 20.8). The incidence reached a peak in 1994 for both sexes and a second higher peak in 2002–2003 for females and in 2006 for males. The lifetime risk of developing CD was 1.8% (2.3% in females and 1.4% in males). Prior to 2015, there was a parallel rise in rates for biopsies showing normal duodenal/jejunal mucosa. Conclusions In Sweden, the incidence of CD increased until 2002–2003 in females and until 2006 in males. Since then, the incidence of CD has declined despite increasing duodenal/jejunal biopsies, suggesting that increased awareness and investigation are unlikely to elevate the incidence of the disease in Sweden. Across a lifetime, 1 in 44 females and 1 in 72 males are expected to be diagnosed with CD in Sweden, indicating a relatively high societal burden of disease.
Utility of Pathology Imagebase for standardisation of prostate cancer grading
AimsDespite efforts to standardise grading of prostate cancer, even among experts there is still a considerable variation in grading practices. In this study we describe the use of Pathology Imagebase, a novel reference image library, for setting an international standard in prostate cancer grading.Methods and resultsThe International Society of Urological Pathology (ISUP) recently launched a reference image database supervised by experts. A panel of 24 international experts in prostate pathology reviewed independently microphotographs of 90 cases of prostate needle biopsies with cancer. A linear weighted kappa of 0.67 (95% confidence interval = 0.62–0.72) and consensus was reached in 50 cases. The interobserver weighted kappa varied from 0.48 to 0.89. The highest level of agreement was seen for Gleason score (GS) 3 + 3 = 6 (ISUP grade 1), while higher grades and particularly GS 4 + 3 = 7 (ISUP grade 3) showed considerable disagreement. Once a two‐thirds majority was reached, images were moved automatically into a public database available for all ISUP members at www.isupweb.org. Non‐members are able to access a limited number of cases.ConclusionsIt is anticipated that the database will assist pathologists to calibrate their grading and, hence, decrease interobserver variability. It will also help to identify instances where definitions of grades need to be clarified.
Pathology Imagebase—a reference image database for standardization of pathology
AimsDespite efforts to standardize histopathology practice through the development of guidelines, the interpretation of morphology is still hampered by subjectivity. We here describe Pathology Imagebase, a novel mechanism for establishing an international standard for the interpretation of pathology specimens.Methods and resultsThe International Society of Urological Pathology (ISUP) established a reference image database through the input of experts in the field. Three panels were formed, one each for prostate, urinary bladder and renal pathology, consisting of 24 international experts. Each of the panel members uploaded microphotographs of cases into a non‐public database. The remaining 23 experts were asked to vote from a multiple‐choice menu. Prior to and while voting, panel members were unable to access the results of voting by the other experts. When a consensus level of at least two‐thirds or 16 votes was reached, cases were automatically transferred to the main database. Consensus was reached in a total of 287 cases across five projects on the grading of prostate, bladder and renal cancer and the classification of renal tumours and flat lesions of the bladder. The full database is available to all ISUP members at www.isupweb.org. Non‐members may access a selected number of cases.ConclusionsIt is anticipated that the database will assist pathologists in calibrating their grading, and will also promote consistency in the diagnosis of difficult cases.