Predictors of Contralateral Disease in Men with Unilateral Lesions on Multiparametric Magnetic Resonance Imaging.

OBJECTIVE:To evaluate predictors of contralateral clinically significant prostate cancer (csPCa) in men with biopsy-proven unilateral lesions on magnetic resonance imaging (MRI). METHODS:We retrospectively identified men with no prior diagnosis of PCa with unilateral biopsy-confirmed csPCa within PI-RADS 2-5 lesions within our institutional biopsy database. Multivariate logistic regression was used to identify clinical predictors of contralateral disease. RESULTS:Four hundred ninety men met study inclusion criteria, of which 385 men (78.6%) had no contralateral csPCa and 105 men (21.4%) had contralateral csPCa (Fig. 1). Prior negative biopsy (OR 0.34 [0.14, 0.75], P = .012), prostate-specific antigen density (OR 18.8 [2.77, 249], P = .017), and tumor location in the transverse plane ("Posterior": OR 1.93 [1.02, 3.87], P = .048; "Throughout Transverse Plane": OR 6.56 [2.26, 19.6], P < .001) were significantly associated with contralateral csPCa in multivariate logistic regression models. However, there appear to be no attributes within the MRI-targeted tumor that reliably predict contralateral csPCa (Table 2). CONCLUSION:Approximately 20% of men with unilateral MRI findings and csPCa on targeted biopsy were found to have contralateral csPCa on systematic biopsy (SB). Prior negative biopsy was associated with a decreased odds of contralateral csPCa. Prostate-specific antigen density and tumor in the posterior aspect of or throughout the transverse plane were associated with increased odds of contralateral csPCA. Consideration of these clinical factors may afford an opportunity to only use SB in cases in which the odds of contralateral csPCa are high.