Risk Factors for Intraprostatic Incision into Malignant Glands at Radical Prostatectomy.

Abstract

Histologically identified intraprostatic incision (IPI) into malignant glands is associated with an increase in biochemical recurrence following radical prostatectomy (RP). However, the predictor of IPI is poorly evaluated. To evaluate the risk factors for IPI into cancer during RP for clinically localized prostate cancer (PCa). Between January 1993 and July 2013, 19 986 men with clinically localized PCa underwent RP at our institution. This study includes 14 434 cases that had complete clinicopathologic data. IPI was defined as an iatrogenic incision into the prostate resulting in the presence of malignant glands at the inked surgical margin, regardless of accompanying pathologic features. Open, retropubic, robot-assisted laparoscopic and pure laparoscopic RP. Univariate and multivariable logistic regression analyses were conducted for risk factors of IPI in RP specimens. The overall incidence of IPI into malignant tissue was noted in 410 (2.8%) cases. In multivariable analysis, obesity, lower prostate weight, surgeon experience, and pure laparoscopic RP were associated with a higher risk of IPI. The odds ratios (OR) for body mass index and prostate weight were 1.05 (95% confidence interval [CI], 1.03-1.08; p<0.001) and 0.99 (95% CI, 0.98-0.99, p<0.001), respectively. The ORs for surgeon experience (>250 cases) and pure laparoscopic RP compared to open RP were 0.71 (95% CI, 0.55-0.90, p=0.005) and 2.05 (95% CI, 1.35-3.11; p=0.001), respectively. The risk of IPI during RP is higher in men with obesity and lower prostate weight. In addition, a pure laparoscopic RP and the early series of each surgeon were associated with a higher risk of IPI. However, tumor characteristics were not associated with the IPI occurrence. Intraprostatic incision occurrence is associated with obesity, small prostate, and surgeon experience and laparoscopic technique but not Gleason score and tumor stage.