Impact of Obesity on Adverse Pathological Characteristics After Radical Prostatectomy

Background: The effect of obesity on pathological features was different from country to country in other studies. To investigate whether obesity affected pathological characteristics of PCa after laparoscopic radical prostatectmy (LRP) in Chinese man. Methods: Medical record of 670 Chinese patients who underwent LRP between 2018 and 2020 were retrospectively reviewed. Patient height and weight were meaured before surgery to calculate the body mass index (BMI). They were categorized into three groups according to Chinese classification of obesity: normol weight (BMI＜24.0kg/m 2 ),overweight (24.0 ≤ BMI ＜28.0kg/m 2 ) and obese(BMI≥28.0kg/m 2 ). The associations between BMI and operating age, preoperative prostate-specific antigen (PSA) level, were assessed with the Kruskal-Wallis test. The associations between BMI and pathological features were assessed with chi –square test. Results: : Of the 670 patients, 31.5% patients were normal weight, 51.3% were overweight, 17.2% were obese. Operating age (P=0.029) tend to decrease as BMI increased. Seminal vesicle invasion differ significantly among BMI categoties (P=0.003), and other adverse pathologic characteristics , such as positive surgical margin (PSM) (P=0.851), International Society of Urological Pathology (ISUP) grade(P=0.194), extracapsular extension(P=0.460) were not associated with BMI categoties. In the Logistic regression model, higher BMI was an independent risk factors for seminal vesicle invasion after adjusting for multiple clinical preoperative characteristics. Conclusions: : Overweight and obese Chinese PCa patients treated by LRP had lower operating age compared to normal weight patients. Seminal vesicle invasion was associated with higher BMI and other adverse pathologic characteristics are not significantly affected by BMI.