The International Society of Urological Pathology (ISUP) and the World Health Organisation have adopted a five-tiered prognostic grade group for prostate cancer in 2014. Grade group 4 is comprised of Gleason patterns 4 + 4, 3 + 5 and 5 + 3. Recent articles have suggested heterogeneity in their prognostic outcomes. We aimed to determine whether there was a difference in mortality outcomes within the ISUP 4 grouping, as identified on needle biopsy. A total of 4080 men who were diagnosed with non-metastatic (N0 M0) prostate cancer on biopsy with Gleason scores of 7, 8 and 9 were included. Multi-variable Cox Regression and Fine and Grey competing risk analysis were used to determine the All-Cause Mortality (ACM) and the Prostate Cancer Specific Mortality (PCSM) as a function of Gleason Scores (Gleason 3 + 4, 4 + 3, 4 + 4, 3 + 5/5 + 3, 9). Gleason score 4 + 4 was utilized as the referent. The 60 months' prostate cancer specific mortality with Gleason patterns 4 + 4 and 3 + 5/5 + 3 were 17% and 20% respectively (P < 0.01). Patients with 3 + 5/5 + 3 disease, had no statistically significant difference in the ACM (adjusted hazard ratio [aHR] 0.99, 95% confidence interval [Cl] 0.68-1.4, p = 0.99) and PCSM risk (aHR 0.77, 95% Cl 0.47-1.2, p = 0.31) when compare with the referent group of patients. Patients with Gleason patterns 4 + 3 and 9 had statistically significant difference in their PCSM risk (aHR 0.70, 95% CI 0.54-0.91, P < 0.001 and aHR 1.5, 95% Cl 1.2-1.9, P < 0.001) when compared to the referent group. Our analysis suggest that ISUP group 4 is homogenous in terms of the all-cause mortality and the prostate cancer specific morality risk as differentiated by the presence of Gleason 5 score.
Pathology oncology research : POR. 2017 Oct 27 [Epub ahead of print]
Thomas Chengxuan Lu, Kim Moretti, Kerri Beckmann, Penelope Cohen, Michael O'Callaghan
University of Adelaide, Adelaide, Australia. ., Queen Elisabeth Hospital, Repatriation Hospital, Woodville, Australia., South Australia Prostate Cancer Clinical Outcomes Collaboration, Repatriation Hospital, Adelaide, Australia., SA Pathology, Royal Adelaide Hospital, Adelaide, Australia.