Up- and downgrading in single intermediate-risk positive biopsy core prostate cancer

Histopathological concordance between prostate biopsies and radical prostatectomy specimens-implications of transrectal and transperineal biopsy approaches

BACKGROUND

This study aimed to evaluate the histopathological concordance rates between prostate biopsies and radical prostatectomy specimens according to the applied biopsy approach (transrectal or transperineal).

METHODS

We studied patients who had been newly diagnosed with clinically significant prostate cancer and who underwent a radical prostatectomy between 2018 and 2022. Patients were included if they underwent a prebiopsy magnetic resonance imaging and if they had not been previously treated for prostate cancer. Histopathological grading on prostate biopsies was compared with that on radical prostatectomy specimens. Univariable and multivariable logistic regression analyses were performed to assess the effect of the applied biopsy approach on histopathological concordance. Additional analyses were performed to assess the effect of the applied biopsy approach on American Urological Association risk group migration, defined as any change in risk group after radical prostatectomy.

RESULTS

In total, 1058 men were studied, of whom 49.3% (522/1058) and 50.7% (536/1058) underwent transrectal and transperineal prostate biopsies, respectively. Histopathological disconcordance was observed in 37.8% (400/1058) of men while American Urological Association risk group migration was observed in 30.2% (320/1058) of men. A transperineal biopsy approach was found to be independently associated with higher histopathological concordance rates (OR 1.33 [95% CI 1.01-1.75], p = 0.04) and less American Urological Association risk group migration (OR 0.70 [95% CI 0.52-0.93], p = 0.01).

CONCLUSIONS

The use of a transperineal biopsy approach improved histopathological concordance rates compared to the use of a transrectal biopsy approach. A transperineal biopsy approach may provide more accurate risk stratification for clinical decision-making. Despite recent improvements, histopathologic concordance remains suboptimal and should be considered before initiating management.

The impact of mpMRI-targeted vs systematic biopsy on the risk of prostate cancer downgrading at final pathology

PURPOSE

Although targeted biopsies (TBx) are associated with improved disease assessment, concerns have been raised regarding the risk of prostate cancer (PCa) overgrading due to more accurate biopsy core deployment in the index lesion.

METHODS

We identified 1672 patients treated with radical prostatectomy (RP) with a positive mpMRI and ISUP ≥ 2 PCa detected via systematic biopsy (SBx) plus TBx. We compared downgrading rates at RP (ISUP 4-5, 3, and 2 at biopsy, to a lower ISUP) for PCa detected via SBx only (group 1), via TBx only (group 2), and eventually for PCa detected with the same ISUP 2-5 at both SBx and TBx (group 3), using multivariable logistic regression models (MVA).

RESULTS

Overall, 12 vs 14 vs 6% (n = 176 vs 227 vs 96) downgrading rates were recorded in group 1 vs group 2 vs group 3, respectively (p < 0.001). At MVA, group 2 was more likely to be downgraded (OR 1.26, p = 0.04), as compared to group 1. Conversely, group 3 was less likely to be downgraded at RP (OR 0.42, p < 0.001).

CONCLUSIONS

Downgrading rates are highest when PCa is present in TBx only and, especially when the highest grade PCa is diagnosed by TBx cores only. Conversely, downgrading rates are lowest when PCa is identified with the same ISUP through both SBx and TBx. The presence of clinically significant disease at SBx + TBx may indicate a more reliable assessment of the disease at the time of biopsy potentially reducing the risk of downgrading at final pathology.

The feasibility of distance to the tumor of biopsy cores to estimate the extracapsular extension

Background

To investigate the predictive capability of a new parameter, the distance between the fibromuscular capsule and the tumor as measured using a prostate biopsy core (referred to as "distance to the tumor" [DTT]), for the presence of extracapsular extension (ECE).

Materials and methods

We analyzed specimens obtained from 246 patients diagnosed with prostate cancer. All patients underwent prebiopsy, prostate magnetic resonance imaging (MRI), and subsequent prostatectomy. DTT measurements were obtained for each prostate biopsy core, and the minimum (min) DTT was extracted. We assessed the relationship between min DTT, MRI-estimated ECE, and pathological ECE, considering factors such as the PI-RADS score and tumor location.

Results

In this study of 246 patients, the mean age was 65.8 years, and the mean prostate-specific antigen (PSA) level was 18.9 ng/ml. Patients with suspicious lesions in the peripheral zone and pathological ECE displayed higher rates of positive digital rectal examination (DRE), elevated PSA levels, and shorter DTT values in the biopsy cores. DTT demonstrated an accurate estimation of the presence of ECE, similar to MRI findings. Min DTT exhibited higher accuracy for peripheral zone masses, with a cutoff value of 1.0 mm for min DTT predicting ECE (AUC: 0.84, sensitivity: 72.23%, specificity: 77.78%, P < 0.01). Of the 246 patients, 66 had no ECE on MRI; however, 18 of these patients displayed pathological ECE, with 14 having DTT values <1.0 mm.

Conclusions

Min DTT, positive DRE results, and a higher Gleason grade were significantly associated with ECE. DTT measurements of <1 mm can provide a more accurate prediction of ECE in the peripheral zone of the prostate than MRI-based assessments.

External Tertiary-Care-Hospital Validation of the Epidemiological SEER-Based Nomogram Predicting Downgrading in High-Risk Prostate Cancer Patients Treated with Radical Prostatectomy

We aimed to externally validate the SEER-based nomogram used to predict downgrading in biopsied high-risk prostate cancer patients treated with radical prostatectomy (RP) in a contemporary European tertiary-care-hospital cohort. We relied on an institutional tertiary-care database to identify biopsied high-risk prostate cancer patients in the National Comprehensive Cancer Network (NCCN) who underwent RP between January 2014 and December 2022. The model's downgrading performance was evaluated using accuracy and calibration. The net benefit of the nomogram was tested with decision-curve analyses. Overall, 241 biopsied high-risk prostate cancer patients were identified. In total, 51% were downgraded at RP. Moreover, of the 99 patients with a biopsy Gleason pattern of 5, 43% were significantly downgraded to RP Gleason pattern ≤ 4 + 4. The nomogram predicted the downgrading with 72% accuracy. A high level of agreement between the predicted and observed downgrading rates was observed. In the prediction of significant downgrading from a biopsy Gleason pattern of 5 to a RP Gleason pattern ≤ 4 + 4, the accuracy was 71%. Deviations from the ideal predictions were noted for predicted probabilities between 30% and 50%, where the nomogram overestimated the observed rate of significant downgrading. This external validation of the SEER-based nomogram confirmed its ability to predict the downgrading of biopsy high-risk prostate cancer patients and its accurate use for patient counseling in high-volume RP centers.