Nerve-sparing procedure not associated with higher PSM rates after RARP
Monday, 8 February 2010- Factors correlated with aggressiveness of cancer, such as clinical stage, pathologic stage, and tumor volume, were the most important predictive factors for positive surgical margins (PSMs), whereas a nerve-sparing procedure was not associated with higher PSM rates after robot-assisted laparoscopic radical prostatectomy, was the conclusion of a report recently published online in European Urology.
“Positive surgical margin after radical prostatectomy (RP) has been shown to be an independent predictive factor for cancer recurrence. Several investigations have correlated clinical and histopathologic findings with surgical margin status after open RP,” wrote the authors. “However, few studies have addressed the predictive factors for PSM after robot-assisted laparoscopic RP (RARP)”.
In the course of the investigation, the group prospectively analysed 876 consecutive patients who underwent RARP from January 2008 to May 2009. All patients underwent RARP performed by a single surgeon with previous experience of >1500 cases.
Stepwise logistic regression was used to identify potential predictive factors for PSM. Three logistic regression models were built:
- one using preoperative variables only
- another using all variables (preoperative, intraoperative, and postoperative) combined
- one created to identify potential predictive factors for PSM location.
Preoperative variables entered into the models included age, body mass index (BMI), prostate-specific antigen, clinical stage, number of positive cores, percentage of positive cores, and AUA symptom score. Intra- and postoperative variables analysed were type of nerve sparing, presence of median lobe, percentage of tumour in the surgical specimen, gland size, histopathologic findings, pathologic stage, and pathologic Gleason grade.
The results of the study revealed that clinical stage was the only preoperative variable independently associated with PSM after RARP. Pathologic stage and percentage of tumour in the surgical specimen were identified as independent predictive factors for PSMs when analysing pre-, intra-, and postoperative variables combined. BMI was shown to be an independent predictive factor for apical PSMs.
Source: Coelho, Rafael F. et al. Predictive factors for positive surgical margins and their locations after robot-assisted laparoscopic radical prostatectomy. European Urology; published online ahead of print 5 February 2010.
