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

ABSTRACT

CONTEXT.­ Effect of tumor nodule (TN) location in the prostate on adverse radical prostatectomy (RP) outcomes is not well studied in contemporary cohorts. OBJECTIVE.­ 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. DESIGN.­ 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. RESULTS.­ 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). CONCLUSIONS.­ These associations may be useful in preoperative surgical planning, particularly with respect to improving radiographic analysis of prostate cancer.