Is body mass index associated with pathological outcomes after radical prostatectomy in Korean men?

UNLABELLED: Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Today, controversies continue with regards to the potential impact of obesity or increased body mass index (BMI) on actual pathological features of prostate cancer and/or clinical outcome after radical prostatectomy (RP). Moreover, a paucity of relevant data exist in the literature regarding Asian or Korean men. For the first time to our knowledge, the study demonstrated that although higher BMI was significantly associated with extracapsular extension of tumour, BMI did not significantly enhance ability to preoperatively predict extracapsular extension of tumour and was not significantly associated with PSA outcome as well as other objective pathological outcomes in Korean men undergoing RP, who are generally leaner than Western counterparts. OBJECTIVE: • To investigate the impact of increased body mass index (BMI) on pathological features after radical prostatectomy (RP) in Korean patients. PATIENTS AND METHODS: • We reviewed the records of 1000 Korean patients who underwent RP for prostate cancer and assessed the differences in pathological outcomes and biochemical recurrence-free survival after RP according to BMI of subjects via univariate and multivariate analyses. • A multivariate logistics regression model, the performance of which was analysed from a receiver operator characteristics curve, was applied to assess the predictive capacity of variables shown to be significant predictors of adverse pathological outcome. RESULTS: • Among our subjects, only 17 (1.7%) men had BMI ≥30 kg/m(2). After adjusting for various clinical variables, BMI (highest quartile vs others) was shown to be significantly associated with extracapsular extension of tumour (P= 0.014) and positive surgical margin (P= 0.019), but not with high pathological Gleason score (P= 0.912) and seminal vesicle invasion (P= 0.191). • Meanwhile, the addition of BMI to a multivariate model devised for preoperatively predicting extracapsular extension of tumour did not significantly increase predictive accuracy of the model (P= 0.319). On multivariate analysis, BMI was not shown to be a significant predictor of biochemical recurrence-free survival (P= 0.201). CONCLUSION: • Although higher BMI was significantly associated with extracapsular extension of tumour, BMI did not significantly enhance the ability to preoperatively predict extracapsular extension of tumour and was not significantly associated with PSA outcome or with other objective pathological outcomes in Korean men undergoing RP, who are generally leaner than their western counterparts.