Obesity leads to a higher rate of positive surgical margins in the context of robot-assisted radical prostatectomy. Results of a prospective multicenter study

Abstract

Introduction Current results concerning the effect of body mass index (BMI) on positive surgical margins (PSMs) after robot-assisted radical prostatectomy (RARP) in patients with localized prostate cancer are inconsistent. Therefore, the aim of this study was to further analyse the association between BMI and PSMs after RARP. Material and methods Between March 2017 and December 2017 a multicentre, prospective, randomised, single-blind series with a blinded outcome assessment of 232 RARP patients was performed. Multivariate logistical regression models were used to analyse the independent effect of obesity, with body-mass-index (BMI) dichotomised at 30 kg/m 2 (model-1) and at 90 th percentile (model-2), on PSMs. Results Median BMI was 27.2 kg/m 2 , PSMs were found in 15.5% (n = 36). In multivariate model-1, obesity did not have a significant effect on PSMs (OR 2.34, p = 0.061). However, if BMI was dichotomized at the 90 th percentile (BMI ≥33.7 kg/m²), patients with a higher BMI showed PSMs four-times more frequently (OR 3.99, p = 0.013). In both models, preoperative prostate-specific antigen (PSA) levels and pathological tumour stage had a significant effect on PSMs. There was no significant correlation between BMI and the extent of PSMs, nor a significant difference between the BMI groups and the localisation of PSMs. There was a higher percentage of posteriolateral PSM localisation in obese patients compared to patients with a BMI of less than 30 kg/m 2 (58.3% and 25.3% of the localisations were posterolateral in obese and non-obese patients, respectively), however this effect was not statistically significant (p = 0.175). Conclusions In addition to a longer operation time and about twice as many complications, patients with a BMI of ≥33.7 kg/m² had a higher PSM rate after RARP. Differences in localization of PSMs in relation to obesity should be evaluated in future research.

High BMI and Surgical Time Are Significant Predictors of Lymphocele after Robot-Assisted Radical Prostatectomy

“…Student et al and Sforza et al confirmed this finding with their multivariate analyses, demonstrating an OR of 1.1 and 1.7, respectively [20,26]. Intraoperative challenging conditions and chronic inflammation in the adipose tissue could provide reasons for the higher risk of postoperative LC and sLC [25][26][27][28]. BMI was also found to be an independent predictor of Clavien 3 complications in patients undergoing RARP with extended PLND [29].…”

Effect of Neoadjuvant Hormonal Therapy on the Postoperative Course for Patients Undergoing Robot-Assisted Radical Prostatectomy

“…Furthermore, the median BMI of NHT cases was significantly higher than that of standard NNHT cases (30 vs. 28, respectively) (p = 0.045). However, obesity in patients undergoing RARP is associated with more difficult intraoperative courses, elevated rates of case abortion, unfavorable postoperative outcomes, increased operating time, reduced nerve-sparing technique, and higher rates of positive surgical margins [20][21][22][23]. Within our cohort, the operating time and catheter days were longer in NHT patients, which may also be influenced by higher BMIs and not merely the high-risk tumor characteristics or the use of neoadjuvant hormonal therapy.…”