The International Society for Urologic Pathology (ISUP) and World Health Organization adopted prognostic Grade Groups 1 to 5 that simplify prostate cancer grading for prognosis. Grade Group 4 is Gleason score (GS) 8 cancer, which is heterogeneous, and encompasses GS 4+4=8, 3+5=8, and 5+3=8. The comparative prognostic implications of these various GS had not been studied by urologic pathologists after re-review of slides.
Patients with a highest biopsy GS 3+5=8 or 4+4=8 were included. Controls were cases with highest GS 4+3=7 or 9-10. Prostatic biopsy cases numbering 423 accessioned from 2005-2013 at 2 institutions were reviewed; clinicopathologic findings and follow-up (median 33.4 months) were assessed.
Among GS 8 cancers, cancer status outcome for 51 men with GS 3+5=8 was marginally worse than for 114 with GS 4+4=8 (p=0.04). This was driven by a persistent non-metastatic (after radiation/hormone therapy) cancer rate of 37% among GS 3+5=8 cases versus 24% among GS 4+4=8 cases. Cancer-specific survival at 36-month follow-up conversely, was 97.8% in the 3+5 cases versus 92.6% in the 4+4 cases, but this was not significant (p=0.089). Cancer-specific survival in GS=8 group was dichotomized by the presence of cribriform growth (p=0.018). All GS categories did not differ in the fraction of biopsy cores positive, clinical presentation, nor the pathologic findings (including the frequency of presence of Gleason pattern 5) of 70 patients who underwent prostatectomy.
Using the most current standards of prostate cancer grading, the prognosis is not different in GS 3+5=8 and 4+4=8 cancers. This justifies inclusion of both in Grade Group 4.
The Journal of urology. 2016 Jun 02 [Epub ahead of print]
Nicholas Harding-Jackson, Oleksandr N Kryvenko, Elizabeth E Whittington, Daniel C Eastwood, George A Tjionas, Merce Jorda, Kenneth A Iczkowski
Department of Pathology, Medical College of Wisconsin, Milwaukee, WI., Department of Pathology and Laboratory Medicine, Miami, FL; Department of Urology, University of Miami Miller School of Medicine, Miami, FL; Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL., Department of Pathology and Laboratory Medicine, Miami, FL., Department of Biostatistics, Medical College of Wisconsin, Milwaukee, WI., Department of Pathology and Laboratory Medicine, Miami, FL., Department of Pathology and Laboratory Medicine, Miami, FL; Department of Urology, University of Miami Miller School of Medicine, Miami, FL; Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL., Department of Pathology, Medical College of Wisconsin, Milwaukee, WI. Electronic address: .