Results
Data from 457 patients who underwent RP after the diagnosis of PCa in 127 patients with combined TBx + SBx and 330 with conventional TRUS-Bx method were evaluated. Patient demographics of the study cohort stratified by biopsy approach are depicted in Table 1. Mean age and PSA values between the groups were similar. The median number of targeted biopsy cores sampled per region of interest (ROI) was 4 (range 2-7).
In the comparison of biopsy ISUP grades between TRUS-Bx and targeted biopsies, higher ISUP grades were detected by combined TBx+SBx. Significant cancer detection was 49.5 % for SBx, 67% for TBx and highest 75.7% for Combination TBx+SBx. There was significant difference in missed cancer ratio between TBx and SBx (10.2% vs 24.4%) that any grade cancer detection by SBx alone was significantly lower than TBx alone.
ISUP distributions and upgrade / downgrade ratios of the methods are also given in Figures 1,2 and Tables 1. Overall Biopsy and surgical pathologic ISUP Grade were concordant in 50% men of the TRUS-Bx and in 57.5 % of the combined TBX+SBx group (p=0.152). Gleason upgrading / downgrading of at least one Gleason Grade Group (GGG) was recorded in 43.3% / 6.7 % patients of the TRUS-Bx, and in 20.5% / 22% of the TBX+SBx group, respectively (all p <0.001).
In the evaluation of conventional TRUS-Bx method according to ISUP grades, concordance achieved in 37.9%, 70%, and 56.1%, in ISUP 1, 2 and 3 grades respectively, at RP pathology. In the TRUS-Bx group, after prostatectomy significant upgrading of 62.1% was detected in ISUP 1 grade.
For ISUP 1 grade, TBx+SBx and TBx showed significantly higher concordance over SBx at RP (Figure 2). Concordance level was significantly higher for ISUP 1 in combined TBx + SBx method compared to conventional TRUS-Bx (61.3% vs 37.9%, p=0.014). In patients with biopsy ISUP 1 exclusively, significant upgrading was seen in TRUS-Bx (62.1%) and SBx (55.5%) when compared to TBx (41.4%) and TBx+SBx (38.7%). Upgrading rates for ISUP 2 were similar in SBx, TBx, TBx+SBx. However, for ISUP 2 downgrading rates were significantly higher in TBx and TBx+SBx when compared to SBx alone. For ISUP Grade 2, SBx and TRUS-Bx showed similar upgrading and downgrading rates. In ISUP 2, all biopsy methods showed similar upgrading but downgrading was higher in TBx and TBx+SBx probably due to over sampling tersiyer 4 pattern in biopsy. Combined TBx+SBx showed significant downgrading in 47.8 % and 54.6 % for ISUP 3 and 4 respectively. For ISUP 3, 4, and 5 groups TBx, SBx, and TBx+SBx showed similar concordances. No upgrading was detected in SBx group for ISUP 3, 4 but downgrading was higher in SBx group when compared to TBx and TBx+SBx . For ISUP grade 2, TRUS-Bx showed the highest concordance among all biopsy methods (70%) with less downgrading. For ISUP 2 and 3 TRUS-Bx showed superior but not significant concordance than combined TBx + SBx method (70% vs 64.7% p=0.509 and 56.1% vs 43.5%, p=0.332). For ISUP 3 and 4, TRUS-Bx showed higher upgrading and less downgrading when compared to TBx+SBx. Conventional TRUS-Bx showed the worst concordance with 17.6% at ISUP Grade 4 with an upgrading rate of 47.1% which might be a reflection of inadequate sampling.