Aim: To evaluate intraprostatic distribution of prostate carcinoma as a function of increasing tumor size and its potential clinical relevance.
Methods: Forty-six prostates with different tumor extent were three dimensionally reconstructed and analyzed with emphasis on number of separate tumors (multifocality) and its distribution on both sides of the urethral midline (laterality).
Results: Three tumor distribution patterns were identified: multiple bilateral without posterior midline crossover, multiple bilateral with crossover, and single bilateral (global) tumors. Unilateral tumors were rare (2%). The pattern of tumor distribution was associated with total tumor volume, presence and volume of high grade component, presence of extracapsular extension, and seminal vesicle involvement. Bilateral tumors with crossover were larger than bilateral tumors without crossover (Spearman's rho=0,728, P<0.001) and were associated with adverse pathological features including capsular penetration, seminal vesicle invasion, and surgical margin involvement. However, only high-grade volume was independently and highly associated with seminal vesicle involvement (OR=2.64, 95%, CI=1.181-5.340, P<0.001). Total (OR=2.53 [1.23-3.74], P<0.001) and index tumor (OR=2.54 [1.31-4.93], P<0.001) volumes were independently associated with capsular penetration.
Conclusions: The distribution of bilateral prostatic carcinomas with and without crossover may have clinical relevance because of their relation to total and high-grade volume.