NCCN Risk Groups Do Not Predict Adverse Pathology or Oncologic Outcomes Among Patients With Grade Group 1 Prostate Cancer in the MRI Era.

BACKGROUND: Prior studies in the pre-MRI era suggest that patients with NCCN Intermediate and High Risk Grade Group 1 prostate cancer (GG1 PCa) on biopsy have increased risk for adverse oncologic outcomes. However, prostate MRI has altered patient selection for biopsy and improved prostate sampling. Herein, we examined factors associated with adverse pathologic features (APF) at radical prostatectomy (RP) and biochemical recurrence (BCR) among patients with GG1 in the MRI era. METHODS: A prospectively maintained institutional prostate cancer registry identified patients with GG1 PCa on biopsy who underwent RP from 2000 to 2023, stratified by MRI use. Multivariable logistic regression and Cox regression identified factors associated with APF at RP (GG3-5, ≥ pT3a, or pN1) and BCR free survival (two consecutive PSA ≥ 0.2 ng/mL), respectively. RESULTS: Among patients without MRI (n = 6732), NCCN risk group was associated with APF, BCR, and distant metastasis. Among 302 patients with GG1 and pre-operative MRI, NCCN risk group was associated with neither APF nor BCR. Age (OR 1.07, 95% CI 1.01-1.14, p = 0.01), PIRADS (p = 0.01), and % core positivity (OR 1.02, 95% CI 1.00-1.03, p = 0.04) were associated with APF. Age (HR 1.07, 95% CI 1.01-1.13, p = 0.03), APF (HR 4.36, 95% CI 2.14-8.86, p < 0.001), and positive margins (HR 4.88, 95% CI 2.39-9.98, p < 0.001) were associated with BCR. CONCLUSIONS: Prior to prostate MRI, NCCN risk groups offered meaningful prognostication among patients with GG1 PCa. However, the utility of NCCN risk groups for GG1 in the MRI era appears limited. Contemporary risk stratification for GG1 should focus on biopsy and MRI characteristics rather than NCCN criteria.