To evaluate whether the spatial distribution of prostate cancer (PCa) influences the concentration of prostate-specific antigen (PSA).

An observational prospective study was performed in 775 consecutive men with preoperative PSA levels ≤20 ng/mL who underwent radical prostatectomy for organ-confined PCa. We evaluated prostate specimens using a cMDX-based map model of the prostate and determined the prostate volume, number of cancer foci, relative tumor volume, Gleason score, zone of origin, localization, and pathologic stage after stratification according to PSA levels categorized into 3 groups: <4 ng/mL, 4-10 ng/mL, and 10.1-20 ng/mL. The distribution of 5254 PCa foci was analyzed after stratification according to PSA levels and visualized on heat maps. A logistic regression analysis was performed to assess the odds ratios of PSA levels for the presence of PCa in 16 regions.

PCa with PSA <4 ng/mL was predominantly localized to the apical part and the peripheral zone of the prostate. PCa with a PSA level 10.1-20 ng/mL (16.4% of cases) was observed more frequently in the anterior part and the base of the prostate than PCa with a PSA level <4 or 4-10 ng/mL (6% and 10%, respectively).

Preoperative PSA levels vary according to the spatial distribution of PCa in radical prostatectomy specimens. The probability of anterior PCa is increased with higher PSA serum levels. Regions of interest harboring the PCa can be defined according to preoperative PSA and prostate volume. These findings are useful to optimize the focal therapy or to adjust the radiation fields.