Five-year Outcomes for Men after Negative Magnetic Resonance Imaging (MRI) or Negative Biopsy in the RAPID MRI-directed Prostate Cancer Diagnostic Pathway

Abstract

Background and objective: There is uncertainty over medium-term cancer outcomes for men who avoid biopsy (Bx) after nonsuspicious magnetic resonance imaging (MRI), and men with a negative Bx after suspicious MRI findings. We report on cancer diagnosis, treatment, and Bx rates for this population over a period of 5 yr.

Methods: This single-centre cohort study followed men discharged from the RAPID prostate cancer diagnostic pathway between 2017 and 2023 with either negative MRI or negative prostate Bx, with at least 3 mo of follow-up. Patients with a Prostate Imaging-Reporting and Data System (PI-RADS) or Likert score of 1-2 on MRI or a score of 3 and prostate-specific antigen (PSA) density (PSAD) of <0.12 ng/ml² underwent PSA monitoring, while those with a score of 3 and PSAD >0.12 ng/ml² or a score of 4-5 were offered prostate Bx. Primary outcomes were grade group (GG) ≥2 diagnosis-free survival (Dx-FS) and treatment-free survival (TFS). Secondary outcomes were GG ≥3 Dx-FS, GG 1 Dx-FS, Bx-free survival (Bx-FS), cancer-specific survival, metastasis, and re-referral. Data were collected using a prospective data registry and electronic clinical records; patients with no recent follow-up (>1 yr) were directly contacted. Kaplan-Meier plots and multivariable Cox regression were used for statistical analysis.

Key findings and limitations: Of 2334 men investigated within the RAPID pathway, 1266 (927 no Bx, 339 negative Bx) were evaluated. Median follow-up was 3.4 yr (interquartile range 2.4-4.9). Seventy-four had GG ≥2 cancer and seven had GG 1 cancer. The 5-yr Dx-FS rates were 91.9% (95% confidence interval [CI] 90.0-93.9%) GG ≥2, 96.3% (95% CI 95.0-97.7%) for GG ≥3, and 99.4% (95% CI 98.9-99.8%) for GG 1. The 5-yr TFS rate was 94.4% (95% CI 92.6-95.9%). The 5-yr Bx-FS rate in the no-Bx group was 79.6% (95% CI 73.7-85.8%), leaving 39% (899/2334) of the original cohort Bx-free. No metastases or cancer-related deaths occurred. Higher PSAD and PI-RADS score and negative Bx, including atypical small acinar proliferation and high-grade prostatic intraepithelial neoplasm findings, did not predict GG ≥2 diagnosis and treatment. Limitations include data excluded because of short follow-up (19%) and the single-centre evaluation.

Conclusions and clinical implications: The RAPID MRI-directed pathway is safe in triaging men for Bx. At 5 yr, only one in 13 patients discharged from the RAPID pathway had GG ≥2 cancer and one in 20 required cancer treatment, while four in ten avoided Bx.

Keywords: Atypical small acinar proliferation; Diagnosis; High-grade prostatic intraepithelial neoplasm; Prostate cancer; Prostate-specific antigen; Prostatitis; Surveillance.