Radical prostatectomy cancer grade and percentage of Gleason pattern 4 estimated by global vs individual tumor grading correlate differently with the risk of biochemical recurrence in Grade Group 2 and 3 cancers

Oleksandr N Kryvenko; Jonathan I Epstein; Ali Merhe; Oleksii A Iakymenko; Ricardo De Almeida E Silva; Dimple Kumar Chanamolu; Laurence M Briski; Deukwoo Kwon; Ivan Nemov; Sanoj Punnen; Alan Pollack; Radka Stoyanova; Dipen J Parekh; Merce Jorda; Mark L Gonzalgo

doi:10.1093/ajcp/aqae003

Radical prostatectomy cancer grade and percentage of Gleason pattern 4 estimated by global vs individual tumor grading correlate differently with the risk of biochemical recurrence in Grade Group 2 and 3 cancers

Am J Clin Pathol. 2024 Feb 27:aqae003. doi: 10.1093/ajcp/aqae003. Online ahead of print.

Authors

Oleksandr N Kryvenko^{1

2

3

4}, Jonathan I Epstein⁵, Ali Merhe², Oleksii A Iakymenko⁶, Ricardo De Almeida E Silva², Dimple Kumar Chanamolu², Laurence M Briski^{6

4}, Deukwoo Kwon^{4

7

8}, Ivan Nemov⁶, Sanoj Punnen^{2

4}, Alan Pollack^{3

4}, Radka Stoyanova^{3

4}, Dipen J Parekh^{2

4}, Merce Jorda^{6

2

4}, Mark L Gonzalgo^{2

4}

Affiliations

¹ Department of Pathology & Laboratory Medicine.
² Desai Sethi Urology Institute.
³ Department of Radiation Oncology.
⁴ Sylvester Comprehensive Cancer Center.
⁵ Departments of Pathology, Urology, and Oncology, Johns Hopkins Medicine, Baltimore, MD, US.
⁶ 1 Department of Pathology & Laboratory Medicine.
⁷ Department of Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, US.
⁸ Division of Clinical and Translational Sciences, Department of Internal Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, US.

PMID: 38412318
DOI: 10.1093/ajcp/aqae003

Abstract

Objectives: There are 2 grading approaches to radical prostatectomy (RP) in multifocal cancer: Grade Group (GG) and percentage of Gleason pattern 4 (GP4%). We investigated whether RP GG and GP4% generated by global vs individual tumor grading correlate differently with biochemical recurrence.

Methods: We reviewed 531 RP specimens with GG2 or GG3 cancer. Each tumor was scored separately with assessment of tumor volume and GP4%. Global grade and GP4% were assigned by combining Gleason pattern 3 and 4 volumes for all tumors. Correlation of GG and GP4% generated by 2 methods with biochemical recurrence was assessed by Cox proportional hazard regression and receiver operating characteristic curves, with optimism adjustment using a bootstrap analysis.

Results: Median age was 63 (range, 42-79) years. Median prostate-specific antigen was 6.3 (range, 0.3-62.9) ng/mL. In total, the highest-grade tumor in 371 (36.9%) men was GG2 and in 160 (30.1%) men was GG3. Global grading was downgraded from GG3 to GG2 in 37 of 121 (30.6%) specimens with multifocal disease, and 145 of 404 (35.9%) specimens had GP4% decreased by at least 10%. Ninety-eight men experienced biochemical recurrence within a median of 13 (range, 3-119) months. Men without biochemical recurrence were followed up for a median of 47 (range, 12-205) months. Grade Group, GP4%, and margin status correlated with the risk of biochemical recurrence using highest-grade tumor and global grading, but the degrees of these correlations varied and were statistically significantly different between the 2 grading approaches.

Conclusions: Grade Group, GP4%, and margin status derived by global vs individual tumor grading predict postoperative biochemical recurrence statistically significantly differently. This difference has important implications if results derived from cohorts graded using different methods are compared.

Keywords: GP4%; global grading; individual tumor; radical prostatectomy.