The Association Between Elevated Body Mass Index and Clinical and Surgical Outcomes in Patients Undergoing Robot-Assisted Radical Prostatectomy: A Retrospective Study

Abstract

Introduction Elevated BMI, including overweight and obesity, is increasingly recognized as a potential risk factor for the development and progression of prostate cancer (PCa). However, its influence on perioperative, pathological, and postoperative outcomes following radical prostatectomy remains a subject of debate. This study sought to evaluate the association between elevated BMI and the clinical, surgical, pathological, and postoperative outcomes in patients undergoing robot-assisted radical prostatectomy. Methods This retrospective observational study included patients with histologically confirmed PCa who underwent robot-assisted radical prostatectomy at a private tertiary care hospital in Brazil between September 2017 and August 2025. Patients were stratified into two groups according to BMI: normal weight (BMI < 25 kg/m²) and elevated BMI (BMI ≥ 25 kg/m²), the latter comprising both overweight and obese individuals based on the World Health Organization (WHO) criteria. Demographic, clinical, intraoperative, pathological, laboratory, and postoperative variables were analyzed and compared between the groups. Missing data were addressed through an available-case analysis. Statistical analyses were performed using appropriate parametric and non-parametric tests, with a p-value < 0.05 considered statistically significant. Results A total of 1,366 patients were included in the analysis. Elevated BMI was significantly associated with a higher prevalence of systemic arterial hypertension (SAH) and diabetes mellitus (both p < 0.001). No significant associations were identified between BMI category and pathological characteristics, including pathological stage, extraprostatic extension, lymph node involvement, International Society of Urological Pathology (ISUP) grade group, seminal vesicle invasion, surgical margin status, tumor volume, or postoperative prostate-specific antigen (PSA) levels. Likewise, no significant differences were observed in intraoperative variables or in most postoperative outcomes. However, patients with elevated BMI were more likely to experience absence of spontaneous postoperative diuresis (p = 0.017). The incidence of postoperative complications did not differ significantly between the groups. Conclusions Elevated BMI was associated with a higher prevalence of metabolic comorbidities but was not linked to significant differences in pathological, intraoperative, or most postoperative outcomes following robot-assisted radical prostatectomy. These findings indicate that excess body weight alone may not negatively affect short-term surgical or pathological outcomes in this population. Further prospective multicenter studies are warranted to elucidate the impact of elevated BMI on PCa prognosis.