To validate a previously proposed prognostic metric, Total Cancer Location (TCLo) density, in a contemporary cohort of men with grade group (GG) 1 prostate cancer (PCa) on active surveillance (AS).
We evaluated 123 patients who entered AS with maximum GG1 PCa at diagnostic and/or confirmatory biopsy. TCLo was defined as the total number of PCa locations identified on both biopsy sessions. TCLo density was calculated as TCLo / prostate volume [ml]. Primary endpoint was progression-free survival (PFS), defined as time from confirmatory biopsy to grade group reclassification (GGR) on repeat biopsy or prostatectomy. Optimal cut-point for TCLo density was predefined in a previously reported cohort and applied to this contemporary cohort. Kaplan-Meier and multivariable Cox regression analysis were used to estimate the association of predictors with PFS.
During median follow-up of 7.8 years, (IQR 7.3-8.2) 34 men had GGR. Using previously defined cut-points, PFS at 5-years was 60% (95% CI: 44%-81%) vs. 89% (95% CI: 83%-96%) in men with high (≥0.06 ml-1) vs. low (<0.06 ml-1) TCLo density, and 63% (95% CI: 48%-82%) vs. 90% (95% CI: 83%-96%) in men with high (≥3) vs. low (≤2) TCLo (log-rank test: P < 0.0001, respectively). Adjusting for age, prostate volume, percent of positive cores and PSA, both higher TCLo density (HR [per 0.01 ml-1 increase]: 1.18, 95% CI: 1.05-1.33, P = 0.005) and TCLo (HR: 1.69, 95% CI: 1.20-2.38, P = 0.002) were associated with shorter PFS.
The previously suggested prognostic value of TCLo density was confirmed in this validation cohort. TCLo alone performed similarly well. Patients with high TCLo density (≥0.06 ml-1) or TCLo (>2) were at greater risk of GGR while on AS. With external validation, these metric may help guide risk-adapted surveillance protocols.
Urologic oncology. 2023 Jan 12 [Epub ahead of print]
Guan Hee Tan, Dominik Deniffel, Antonio Finelli, Marian Wettstein, Ardalan Ahmad, Alexandre Zlotta, Neil Fleshner, Robert Hamilton, Girish Kulkarni, Gregory Nason, Khaled Ajib, Jaime Herrera-Caceres, Thenappan Chandrasekar, Nathan Perlis
University Health Network, Sprott Department of Surgery, Division of Urology, University of Toronto, Toronto, Canada; Sunway Medical Centre, Bandar Sunway, Selangor, Malaysia., Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Germany; Joint Department of Medical Imaging, University Health Network, Sinai Health System and University of Toronto, ON, Canada., University Health Network, Sprott Department of Surgery, Division of Urology, University of Toronto, Toronto, Canada., University Health Network, Sprott Department of Surgery, Division of Urology, University of Toronto, Toronto, Canada; Division of Urology, Sinai Health System, Toronto, Canada., Department of Urology, Thomas Jefferson University, Philadelphia, PA., University Health Network, Sprott Department of Surgery, Division of Urology, University of Toronto, Toronto, Canada. Electronic address: .