Assessment of Diagnostic Performance of Risk Factors Affecting Extraprostatic Extension: Role of Zonal Level of Prostate Cancer

Abstract

Objective: Extraprostatic extension (EPE) serves as a crucial marker of prostate cancer aggressiveness and independently predicts the likelihood of biochemical recurrence (BCR), exhibiting a strong correlation with the histologic severity of EPE. Therefore, this study aimed to investigate the probability of EPE along the zonal level of the prostate by measuring tumor contact length (TCL) using multiparametric magnetic resonance imaging (mpMRI). Patients and Methods:: Records of 308 patients who had undergone radical prostatectomy (RP) were identified. Tumor levels in the prostate were categorized as apex, mid-gland, and base, after which the correlation between TCL measured using MRI and microscopic EPE on pathologic specimens was evaluated. Univariable and multivariable logistic regression analyses were performed to assess the association among tumor origin, index tumor diameter, and TCL measured using MRI and microscopic EPE in RP specimens. Results: Among the 214 patients included, 45 apical cancers (21%), 87 mid-gland cancers (41%), and 82 base cancers (38%) were observed. Pathological reports revealed that 18 (40.0%) apex, 31 (35.6%) mid-gland, and 50 (61.0%) base tumors were pT3a. Multivariable analysis demonstrated that the zonal level of the tumor, especially the base level, was an independent predictive factor for EPE (P < 0.001), and the AUC value of the base tumor was 0.858. Conclusion: Prostate cancers arising from the base were more likely to exhibit EPE than those arising from the mid-gland and apex of the prostate gland. Therefore, identifying the origin of the zonal level of prostate cancer may help guide treatment decisions and predict clinical prognosis.