The prognostic nomogram for PSA-incongruent low-risk prostate cancer treated by radical prostatectomy

Abstract

Objective: To establish a prognostic nomogram for PSA-incongruent low-risk prostate cancer (PCa) patients (Gleason score 6 and clinical stage T2a) at diagnosis and treated with radical prostatectomy (RP), based on clinical and pathological metrics.

Methods: In total, 217 patients diagnosed with PCa were included in this study. All patients had a Gleason score of 6 (GS6) in biopsy, had clinical T2a before surgery and were treated with RP. Biochemical progression-free survival (bPFS) was analyzed using the Kaplan-Meier method. Univariate and multivariate analyses were used to determine prognostic factors related to bPFS. A prognostic nomogram was established based on factors that were significant in the multivariate analyses.

Results: The median bPFS had a significant difference in the subgroup of PSA at diagnosis (' < 10 ng/mL': 71.698 [67.549-75.847] vs '10-20 ng/mL': 71.038 [66.220-75.857] vs ' ≥ 20 ng/mL': 26.746 [12.384-41.108] months [Log Rank P < 0.001]), the subgroup of T stage upgrade (Negative: 70.016 [65.846-74.187] vs 'T2b/c': 69.183 [63.544-74.822] vs 'T3/4': 32.235 [11.877-52.593] months [Log Rank P < 0.001]) and the subgroup of Gleason score upgrade (Negative: 72.63 [69.096-76.163] vs '3 + 4': 68.393 [62.243-74.543] vs '4 + 3': 41.427 [27.517-55.336] vs ' ≥ 8': 28.291 [7.527-49.055] [Log Rank P < 0.001]). PSA at diagnoses (Hazard Ratio (HR) 1.027, 95% CI 1.015-1.039, P < 0.001), T stage upgrade (HR 2.116, 95% CI 1.083-4.133, P = 0.028), and Gleason score upgrade (HR 2.831, 95% CI 1.892-4.237, P < 0.001) were identified as independent predictors with significance in multivariable Cox regression analysis. A nomogram was established based on these three factors.

Conclusions: Our study indicated that PSA-incongruent low-risk PCa patients (PSA with 10-20 ng/mL) had a similar prognosis to those with real low-risk PCa (PSA < 10 ng/mL) in the D' Amico criteria. We also established a nomogram based on three significant prognostic factors, including PSA at diagnosis, T stage upgrade, and Gleason score upgrade, which were associated with clinical outcomes in prostate cancer patients with GS6 and T2a after surgery.

Keywords: Biochemical progression-free survival; Clinical T stage; Gleason score; PSA-incongruent low-risk prostate cancer; Prognostic nomogram; Radical prostatectomy.