Repeated biopsies in prostate cancer patients on active surveillance: clinical implications of interobserver variation in histopathological assessment

TY - JOUR

T1 - Repeated biopsies in prostate cancer patients on active surveillance

T2 - clinical implications of interobserver variation in histopathological assessment

AU - Thomsen, Frederik Birkebaek

AU - Marcussen, Niels

AU - Berg, Kasper Drimer

AU - Christensen, Ib Jarle

AU - Vainer, Ben

AU - Iversen, Peter

AU - Brasso, Klaus

N1 - This article is protected by copyright. All rights reserved.

PY - 2015/4/1

Y1 - 2015/4/1

N2 - ObjectiveTo investigate the clinical implications of interobserver variation in the assessment of re-biopsies obtained during active surveillance (AS) of prostate cancer. Patients and Methods In all, 107 patients with low-risk prostate cancer with 93 diagnostic biopsy sets and 109 re-biopsy sets were included. The International Society of Urological Pathology 2005 Gleason scoring system was used for the histopathological assessment of all biopsies. Three different definitions of histopathological progression were applied. Unweighted and linear weighted Kappa (κ) statistics were used to compare the interobserver agreement. Results The overall Gleason score agreement was 68.8% with a weighted κ of 0.670. The interobserver agreement was 79.6% for meeting the AS selection criteria. According to the three progression definitions applied, overall agreement was between 80.7% and 89.0% with weighted κ values of 0.746-0.791. Treatment recommendations would have changed in up to 10.1% (95% confidence interval 5.4-17.7%) of the 109 re-biopsy sets. Conclusion Kappa statistics showed strong agreement between the histological evaluations. However, up to 10% of patients on AS would receive a different treatment recommendation depending upon which histopathological evaluation of re-biopsies was used for treatment planning.

AB - ObjectiveTo investigate the clinical implications of interobserver variation in the assessment of re-biopsies obtained during active surveillance (AS) of prostate cancer. Patients and Methods In all, 107 patients with low-risk prostate cancer with 93 diagnostic biopsy sets and 109 re-biopsy sets were included. The International Society of Urological Pathology 2005 Gleason scoring system was used for the histopathological assessment of all biopsies. Three different definitions of histopathological progression were applied. Unweighted and linear weighted Kappa (κ) statistics were used to compare the interobserver agreement. Results The overall Gleason score agreement was 68.8% with a weighted κ of 0.670. The interobserver agreement was 79.6% for meeting the AS selection criteria. According to the three progression definitions applied, overall agreement was between 80.7% and 89.0% with weighted κ values of 0.746-0.791. Treatment recommendations would have changed in up to 10.1% (95% confidence interval 5.4-17.7%) of the 109 re-biopsy sets. Conclusion Kappa statistics showed strong agreement between the histological evaluations. However, up to 10% of patients on AS would receive a different treatment recommendation depending upon which histopathological evaluation of re-biopsies was used for treatment planning.

U2 - 10.1111/bju.12820

DO - 10.1111/bju.12820

M3 - Journal article

C2 - 24903618

SN - 1464-4096

VL - 115

SP - 599

EP - 605

JO - BJU International

JF - BJU International

IS - 4

ER -