Gleason 6 on biopsy – predicting the risk of harbouring higher-grade cancer

Research output: Contribution to conferenceAbstract

Abstract

Introduction: Active surveillance (AS) is increasingly being recommended as the preferred treatment option for patients with low-grade disease. However, the Gleason score reported on biopsy is not always in concordance with the final pathology in patients who have radical prostatectomies (RP). Recommending patients for AS based on biopsy Gleason score can have huge implication if in fact they have disease of higher-grade. We aim to determine the patient characteristics at the time of diagnosis, which predicts the likelihood of patients with Gleason score 6 on biopsy, harbouring higher-grade cancer. Methods: The study samples were obtained from the Prostate Cancer Registry. Patients who had Gleason score 6 on biopsy and proceeded to have RP as their primary treatment between August 2008 and September 2013 were included in this study. Patients who had neo-adjuvant treatment prior to RP were excluded. The association between patient characteristics at the time of diagnosis and disease upgrading were analysed using univariate and multivariate logistic regression. Results: Of the 894 patients included in the study, only 304 (34%) patients had Gleason score 6 on the RP specimens, and as many as 567 (63%) patients have at least Gleason score 7 on the RP specimens, of which 461 (52%) have Gleason score 7 (3 + 4), 85 (9.5%) have Gleason score 7 (4 + 3) and 21 (2%) have Gleason score 8–9. The median time between biopsy and RP was 10 weeks (IQR: 6–19). In univariate analysis, age at diagnosis, clinical stage (cT1 vs. cT2/3/4), percent of positive cores and hospital where the biopsies were performed (rural vs. metropolitan) are significantly associated with disease upgrading. In multivariate analysis, only increasing age at diagnosis (OR = 1.03, 95% CI = 1.01–1.06, P = 0.03) and higher percent of positive cores (OR = 1.01, 95% CI = 1.003–1.019, P = 0.006) are statistically significantly associated with increased likelihood of disease upgrading, after adjusting forthe duration between biopsy and RP as well as the hospital where RP was performed. Conclusions: A significant proportion of prostate cancer patients who have Gleason score 6 on biopsy in fact have higher-grade disease. It is imperative for clinicians to take into account the overall likelihood that the cancer might have been under- graded on the diagnostic biopsy, when offering treatments optimized for patients with low-grade disease such as active surveillance.
Original languageEnglish
Pages39-40
Number of pages2
DOIs
Publication statusPublished - 1 Jul 2014
EventUrological Society of Australia and New Zealand Annual Scientific Meeting: Future Proofing Urology - Brisbane Convention and Exhibition Centre, Brisbane, Australia
Duration: 16 Mar 201419 Mar 2014
Conference number: 67th

Conference

ConferenceUrological Society of Australia and New Zealand Annual Scientific Meeting
Abbreviated title2014 USANZ Annual Scientific Meeting
CountryAustralia
CityBrisbane
Period16/03/1419/03/14

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