In this presented study, a total of 659 patients who underwent MRI-targeted biopsy and subsequent radical prostatectomy between 2016 and 2018 at five referral centers were identified. All patients received MRI-targeted biopsies combined with systematic biopsy. The D’Amico risk groups and the rate of upgrading at final pathology were assessed considering the grade group at targeted biopsy and after adding information from the systematic biopsy. Moreover, a multivariable logistic regression model assessing the impact of MRI-targeted biopsy parameters on the risk of upgrading was developed. The parameters included in the model were PSA, prostate volume, grade group at target biopsy, clinical stage and the maximum diameter of the lesion at mpMRI. Furthermore, an additional model that included information on clinically significant prostate cancer outside the index lesion, and the number of random positive and total cores was developed as well.
Table 1 demonstrates the patient characteristics, figure 1 shows the biopsy grade groups, and figure 2 demonstrated the D’Amico risk groups. When information obtained by systematic biopsy was added, 42 (6.4%), 451 (68%) and 166 (25%) men were classified as low-, intermediate- and high-risk, respectively. Furthermore, 40 (46%) of low-risk patients were reclassified as intermediate-risk, and 5 (5.8%) and 33 (7.4%) low- and intermediate-risk patients, respectively, were reclassified as high-risk.
Table 1 – Patient Characteristics:
Figure 1 – Biopsy Grade Groups of the Targeted and Systematic Bbiopsies:
Figure 2- D’Amico Risk Groups:
The rate of upgrading decreased from 32% for targeted biopsies to 26% when adding information from systematic biopsy (P=0.04), as shown in figure 3. The multivariable models (Table 2) demonstrated that the presence of significant disease at systematic biopsy and a higher number of systematic cores taken were associated with a reduced risk of upgrading (all P≤0.01).
Figure 3 – Upgrading in FInal Radical Prostatectomy Specimen of Targeted and Systematic Bbiopsies:
Table 2 – Results of Both Multivariable Models:
The authors concluded that adding systematic biopsy to MRI-targeted cores reduces the risk of upgrading at final pathology. The authors state that there is a need to add accurate systematic biopsy sampling, in addition to the targeted biopsies, in order to improve the accuracy of tumor grading and to optimize patient selection for the appropriate treatment modalities.
Presented by: Giorgio Gandaglia MD, IRCCS Ospedale San Raffaele, Unit of Urology, Division of Oncology, Milan, Italy
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain, March 15-19, 2019.