A combination of prostate-specific antigen density, multiparametric magnetic resonance imaging, and prostate-specific membrane antigen positron emission tomography/computed tomography findings may identify a highly selected subgroup of patients with prostate cancer for future investigation of biopsy-sparing diagnostic pathways.
Investigators retrospectively evaluated 413 patients who underwent radical prostatectomy (RP) for prostate cancer between December 2015 and December 2024 and had multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT). All patients underwent prostate biopsy, but biopsy-related variables were excluded from the primary analysis. The median age was 64.9 years.
The authors evaluated adverse pathology at radical prostatectomy, defined as International Society of Urological Pathologists grade 3 or higher disease and/or extraprostatic disease of pT3 or higher or pN1. Clinical and imaging variables included prostate-specific antigen (PSA), PSA density (PSAD), Prostate Imaging Reporting and Data System (PI-RADS) scores and lesion characteristics on mpMRI, and maximum standardized uptake value (SUVmax) on PSMA PET/CT. A prostatic SUVmax of at least 12 was classified as PRIMARY 5.
Overall, 248 of 413 patients (60%) had adverse pathology. The rate was 48% among patients with PSAD of 0.15 or lower vs 72% among those with PSAD greater than 0.15. Adverse pathology was identified in 45% of patients with PI-RADS 3 or lower findings, 52% with PI-RADS 4, and 80% with PI-RADS 5. Rates were 55% among patients with PRIMARY 1 to 4 and 85% among those with PRIMARY 5.
Age, PSAD, PI-RADS 5 on mpMRI, and PRIMARY 5 on PSMA PET/CT were independently associated with adverse pathology in multivariable analysis. The combined model showed greater discrimination for adverse pathology than any of the individual clinical or imaging parameters.
When the investigators combined the clinical and imaging predictors, all 22 patients with PSAD greater than 0.15, PI-RADS 5, and PRIMARY 5 had adverse pathology at radical prostatectomy. The triple-positive profile had 100% specificity and 100% positive predictive value, although sensitivity was 9% and negative predictive value was 42%. Among these 22 patients, 12 (55%) had Gleason score 8 to 10 disease with pT3 or pT4 disease, and 6 (27%) had pN1 disease.
The potential applicability of the profile was narrow, as only 22 patients in the overall cohort met all 3 criteria. The investigators proposed the combination as potential inclusion criteria for future prospective studies of biopsy omission rather than as an established basis for eliminating biopsy.
The study was limited by its retrospective design, with the potential for selection bias and unmeasured confounding. The population was highly selected and relatively homogeneous, with high rates of clinically significant prostate cancer and adverse pathology. The single-center design and inclusion of only patients with available PI-RADS and SUVmax data may also limit generalizability. Imaging was performed or reviewed at experienced centers, and the researchers noted that external validation was warranted before the criteria could be adopted in future prospective studies.
The findings suggest that combining PSAD, mpMRI, and PSMA PET/CT may help define a highly selected population for prospective investigation of biopsy-sparing strategies. The researchers also noted that biopsy provides histologic information important for treatment planning and that the proposed imaging-based approach requires further study.
“Our study identified a very specific subgroup of patients consistently associated with adverse pathology at RP using a combination of PSAD, PI-RADS score on mpMRI, and SUVmax on PSMA PET,” wrote lead study author Barış Esen, of Koç University Hospital and Emory University School of Medicine, and colleagues.
Disclosures: The authors reported no conflicts of interest.
Source: European Urology Open Science
