Anterior or Posterior Prostate Cancer Tumor Nodule Location Predicts Likelihood of Certain Adverse Outcomes at Radical Prostatectomy.

Effect of tumor nodule (TN) location in the prostate on adverse radical prostatectomy (RP) outcomes is not well studied in contemporary cohorts. To investigate the significance of TN location with respect to extraprostatic extension (EPE), seminal vesicle invasion (SVI), and positive surgical margin (SM+) in 1388 RPs. Each TN at RP was independently graded, staged, and volumetrically assessed. TNs with at least 80% of their volume occupying either the anterior or posterior part of the prostate were categorized accordingly and included in our study, while all other TNs were excluded. A total of 3570 separate TNs (median = 3 per RP; range = 1-7 per RP) were scored. There were 1320 of 3570 (37%) anterior TNs and 2250 of 3570 (63%) posterior TNs. Posterior TNs were more likely to be higher grade, and exhibit EPE (18% versus 9.4%) and SVI (4% versus 0.15%), all P < .001. Anterior TNs with EPE were more likely to exhibit SM+ than posterior TNs with EPE (62% versus 30.8%, P < .001). TN location, grade, and volume were significant factors associated with adverse RP outcomes in our univariable analysis. When we controlled for grade and tumor volume in a multivariable analysis using anterior TN location as a reference, posterior TN location was an independent predictor of EPE and SVI and was less likely to be associated with SM+ (odds ratio = 3.1, 81.5, and 0.7, respectively). These associations may be useful in preoperative surgical planning, particularly with respect to improving radiographic analysis of prostate cancer.