MP09-02: Is it clinically and oncologically safe to omit prostate biopsy in low risk stratified patients?

Henning Bahlburg*, Karl Heinrich Tully, Vincent Hoffmann, Herne, Germany, Julian Hanske, Recklinghausen, Germany, Nicolas von Landenberg, Florian Roghmann, Rein-Jueri Palisaar, Joachim Noldus, Sebastian Berg, Herne, Germany, Marko Brock, Recklinghausen, Germany

Introduction: According to current guidelines, decision making to perform prostate biopsies (PBx) should be based on individual cancer risk assessment. The risk-stratified pathway (RSP) is aiming to reduce the number of PBx and consequently both complications and overdiagnosis of clinical insignificant prostate cancer (PCa). As patients classified as low risk using the RPCRC are advised not to undergo PBx, there is concern about missing clinically significant PCa. Therefor a clear pathway is needed to follow up these individuals. We analyzed a safety net relying on PSA-density and clinical follow-up.

Methods: We systematically collected follow-up data for 123 consecutive patients with a low pre-PBx risk of PCa who underwent systematic follow up after having been advised against undergoing PBx between 07/2019 and 02/2020. Every patient was encouraged to adhere to a PSA-density based safety net. Cut off values indicating a re-evaluation were defined as a PSA-density >0,15ng/ml in biopsy naïve patients, and >0,2ng/ml in patients with past biopsies. Additionally, we advised to perform biopsy when risk stratification revealed a change in risk stratification from low to intermediate or high risk of clinically significant PCa. Paired t-test was employed to examine changes in risk-stratification when employing a PSA-density based safety net for patients who did not undergo PBx in the RSP.

Results: Follow-up data was available for 122 patients who did not receive biopsies after initial low risk stratification. The median follow-up was 12 months (IQR 9, 15 months). In this group, 86.2% adhered to the proposed safety net based on PSA-density and digital rectal exam. Follow-up showed that risk stratification did not change (p=0.277) with the majority of patients (82.9%, n=102) showing an identical risk of clinically significant PCa. Additionally, the pre-PBx risk decreased in 7.3%(n=9) of the cohort, while it increased in 9.8% of patients(n=12). All patients with an increased risk at follow-up underwent PBx. Histopathologic analyses revealed PCa in none of these cases.

Conclusions: Implementing the risk stratified pathway can significantly decrease prostate biopsies. However, it is important that patients who do not receive a prostate biopsy are monitored closely. When doing so, risk stratification should be performed repeatedly on current PSA-levels and digital rectal examination. According to our data, a PSA-density based follow-up after initial low-risk stratification offers a safe option with minimal risk of missing occult clinically significant tumors.

Source of Funding: none