Background: To examine whether diagnostic biopsy (B1), for patients on active surveillance (AS) for prostate cancer, performed at an outside referral centre (external) compared with our in-house tertiary center (internal), increased the risk of re-classification on the second (confirmatory) biopsy (B2).
Methods: Patients on AS were identified from our tertiary center database (1997-2012) with PSA< 10, Gleason sum (GS) ⩽ 6, clinical stage ⩽ cT2, ⩽ 3 positive cores, < 50% of single core involved, age ⩽ 75 years and having a B2. Patients who had < 10 cores at B1 and delay in B2 >24 mo were excluded. Depending on center where B1 was performed, men were dichotomized to internal or external groups. All B2 were performed internally. Multivariate logistic regression examined if external B1 was a predictor of re-classification at B2.
Results: A total of 375 patients were divided into external (n=71, 18.9%) and internal groups (n=304, 81.1%). At B2, more men in the external group re-classified (26.8%) compared with the internal group (13.8%)(P=0.008). On multivariate analysis, external B1 predicted grade-related re-classification (odds ratio (OR) 4.14, confidence interval (CI) 2.01-8.54, P< 0.001) and volume-related re-classification (OR 3.43, CI 1.87-6.25, P< 0.001). Other significant predictors for grade-related re-classification were age (OR 2.13 per decade, CI 1.32-3.57, P< 0.001), PSA density (OR 2.56 per unit, CI 1.44-4.73, P< 0.001), maximum % core involvement (OR 1.04 per percentage point, CI 1.01-1.09, P=0.02) and time between B1 and B2 (OR 1.43 per 6 months, CI 1.21-1.71, P< 0.001).
Conclusion: At our institution, patients on AS who had their initial B1 performed externally were more likely to have adverse pathological features and re-classify on internal B2.
Wong LM, Ferrara S, Alibhai SM, Evans A, Van der Kwast T, Trottier G, Timilshina N, Toi A, Kulkarni G, Hamilton R, Zlotta A, Fleshner N, Finelli A. Are you the author?
Division of Urologic Oncology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada; Department of Urology and Surgery, University of Melbourne, St Vincent's Hospital Melbourne, Melbourne, Victoria, Australia; Department of Medicine, University Health Network, Toronto, Canada; Department of Pathology, University Health Network, Toronto, Canada; Department of Radiology, University Health Network, Toronto, Canada.
Reference: Prostate Cancer Prostatic Dis. 2014 Dec 9. Epub ahead of print.