Single Positive Core Prostate Cancer Has Less Aggressive Pathologic Features than Multiple Positive Core Prostate Cancer but Should It Still Be Considered an Indolent Tumor?

Abstract

Introduction: A single positive core (SPC) in a prostate biopsy is usually associated with indolent prostate cancer (PCa), and is considered one active surveillance criteria. To determine if a SPC should qualify a patient for surveillance, we compared the pathological findings for SPC and multiple positive core in a matched population who underwent radical prostatectomy (RP). Material and Methods: We evaluated 373 SPC patients who underwent RP (Group 1) and 375 consecutive cases with multiple positive core (Group 2) who were matched according to age, prostate weight, PSA level and clinical stage. In addition to preoperative data and epidemiological characteristics, we compared the rates of positive surgical margins (PSMs), extraprostatic extension (EPE) and seminal vesicle invasion (SVI) according to the Gleason scores (GSs) of the biopsies. Results: Both groups were similar according age, PSA level, prostate weight and clinical stage. Group 1 had a lower PSM rate (20.9% vs 37.6%, p < 0.001), less EPE (10% vs 26%, p < 0.001) and SVI (6% vs 13.3%, p = 0.006). The PSM, EPE and SVI rates increased with increasing GS in both groups. In Group 1, a patient with a GS ≥ 8 was 3.5 times more likely to have a PSM than a patient with a GS ≤ 6 (p = 0.03); with no difference in Group 2 (p = 0.162). There were no correlations between the EPE and SVI rates and the GS in Group 1 (p = 0.273 and p = 0.95, respectively). However, in Group 2, we observed a higher rate of EPE among GS 7 than among GS ≤ 6, OR = 3.1 (p < 0.001). We also observed a higher rate of SVI among GS 7 than among GS ≤ 6 in Group 2, OR = 3.1 (p = 0.004). Conclusion: SPC PCa have reduced rates of PSM, EPE and SVI relative to multiple positive core. However, these pathologic findings were observed in 6.0% - 20.9% of SPC, especially in undifferentiated tumors. These results led us to conclude that active treatment instead of active surveillance should be considered and must be evaluated individually for SPC patients, especially those with higher GSs.