Association of Systematic Biopsy vs. Magnetic Resonance Imaging/Ultrasound Fusion Targeted Biopsy with Prostate Cancer Upstaging at Radical Prostatectomy
INTRODUCTION
Magnetic resonance imaging (MRI)/ultrasound fusion targeted biopsy has demonstrated favorable detection rates of clinically-significant prostate cancer compared with systematic biopsy. However, the predictive role of targeted vs systematic biopsy in upstaging at radical prostatectomy remains undefined. We sought to determine the prognostic value of targeted vs systematic in upstaging to ≥T3a at radical prostatectomy.
METHODS
We retrospectively queried an institutional database to identify men who underwent systematic and targeted biopsies followed by radical prostatectomy between April 2015 and June 2017. Upstaging was regarded as pathological stage ≥T3a after radical prostatectomy with clinical stage ≤T2c. Clinical and pathological variables were compared based on organ confinement status. Binary logistic regression was performed to identify clinical, radiological, and targeted vs. systematic biopsy pathologic features associated with the presence of upstaging from biopsy to radical prostatectomy.
RESULTS
Upstaging was identified at radical prostatectomy in 39/95 (41%) patients. Patients with upstaging at radical prostatectomy had elevated prostate-specific antigen (median 9 vs. 6.3, P=0.007), higher proportion of positive targeted biopsy cores (0.8 vs. 0.6, P=0.01) and maximum percent targeted biopsy core involvement (85% vs. 75%, P=0.01), and higher rate of perineural invasion (PNI) on systematic biopsy (28% vs. 9%, P=0.02). Moreover, compared with organ-confined disease, upstaging was more detected in greater biopsy grade groups on targeted (P=0.01) and systematic biopsies (P=0.02), and among patients with prostate imaging reporting and data system (PI-RADS) score 5 on MRI (P=0.007). On multivariable analysis including targeted biopsy tumor involvement, PI-RADS score, total biopsy grade groups, PNI on systematic biopsy (OR 5.27, 95%CI 1.27-21.77, P=0.02) and clinical T1c (OR 4.16, 95%CI 1.21-13.51, P=0.02) remained significantly associated with an increased risk of upstaging at radical prostatectomy.
CONCLUSION
PNI on systematic biopsy is a significant predictor of upstaging to ≥T3a at radical prostatectomy, whereas no targeted biopsy pathological features yielded a significant association. Systematic biopsy maintains an important role in the prediction of non-organ confined disease in patients with prostate cancer.
Funding: None