Obesity and capsular incision at the time of open retropubic radical prostatectomy.

PURPOSE: The goal of radical prostatectomy (RP) is complete removal of the intact prostate. Obese men can represent a technical challenge. However, to our knowledge objective data linking obesity with technically inferior surgery are lacking. Therefore, we examined the association between body mass index (BMI) and capsular incision at RP as a surrogate of a poor technical operation in men treated for prostate cancer by several high volume surgeons at a center of excellence. MATERIALS AND METHODS: The study population consisted of 7,027 men treated with anatomical retropubic RP between 1996 and 2004 by 7 high volume surgeons. We evaluated the association between BMI and capsular incision using logistic regression, adjusting for clinical and pathological variables, and for the surgeon. RESULTS: Overall capsular incision was noted in 4.6% of all RP specimens. After adjustment for preoperative prostate specific antigen, patient race, height, year of surgery, clinical stage, pathological Gleason sum, prostate weight, extraprostatic extension and seminal vesicle invasion increased BMI was associated with increased odds of capsular incision (p trend = 0.005). After further adjustment for surgeon mild obesity was associated with 30% increased odds of capsular incision (OR 1.30, 95% CI 0.92 to 1.83), while moderate and severe obesity was associated with 57% increased odds of capsular incision (OR 1.57, 95% CI 0.82 to 3.00) relative to normal weight men (p trend = 0.06). CONCLUSIONS: In a study of more than 7,000 men treated by 7 experienced surgeons BMI was positively related to capsular incision. This suggests that open retropubic RP is technically more difficult in obese men, which results in a greater likelihood of a less than technically ideal operation. Although this may be predicted to have a negative impact on disease-free survival outcomes in obese men, it is unlikely to alone explain the worse outcomes in obese men noted in previous RP series.

Association between serum adiponectin, and pathological stage and grade in men undergoing radical prostatectomy.

PURPOSE: Adiponectin is a polypeptide hormone produced by adipocytes that has anti-angiogenic properties. Circulating adiponectin is lower in obese men. Obesity has been associated with advanced stage and a higher risk of biochemical progression following radical prostatectomy (RP) in several series. We examined whether serum adiponectin is associated with advanced disease stage at RP. MATERIALS AND METHODS: Adiponectin was measured by enzyme-linked immunosorbent assay in the preoperative serum of 236 men treated with RP between 1998 and 1999. The odds ratio (OR) of advanced stage (pT3a or greater) and high grade disease (pathological Gleason sum 7 or greater) associated with quartiles of adiponectin were estimated using multivariate logistic regression models. RESULTS: Serum adiponectin weakly correlated inversely with body mass index (Spearman r = -0.22, p = 0.01). Serum adiponectin was not associated with cancer stage or grade. However, in normal weight men adiponectin was positively associated with high stage disease (OR 1.14, 95% CI 1.02 to 1.29, p = 0.03), although there was no statistically significant association with high grade disease (OR 1.05, 95% CI 0.94 to 1.18, p = 0.38). In overweight and obese men adiponectin was inversely associated with high grade disease (OR 0.94, 95% CI 0.87 to 1.01, p = 0.09), although there was no statistically significant association with high stage disease (OR 0.97, 95% CI 0.91 to 1.04, p = 0.43). Further adjustments for body mass index had little impact on any ORs. CONCLUSIONS: These data provide evidence to suggest that adiponectin may be related to prostate cancer aggressiveness, although the direction of the associations may depend on the extent of adiposity and on cancer grade.

Obesity and risk of biochemical progression following radical prostatectomy at a tertiary care referral center.

PURPOSE: We have previously reported that obesity is an independent predictor of biochemical progression after radical prostatectomy (RP) in men treated by a single surgeon at our institution. We sought to validate or refute these findings using data on men treated by multiple other surgeons at our institution. MATERIALS AND METHODS: The study population consisted of 2,796 men treated with anatomical radical RP between 1988 and 2004 by 1 of 17 surgeons at our institution, a tertiary care referral center. We evaluated the association between body mass index (BMI), and adverse pathological features and biochemical progression. RESULTS: On multivariate analysis increased BMI was associated with high grade disease in the RP specimen (p = 0.03), positive surgical margins (p <0.001), extraprostatic extension (p <0.001) and lymph node metastasis (p = 0.01) but not with seminal vesicle invasion (p = 0.59). After multivariate adjustment for preoperative clinical characteristics increased BMI was significantly associated with an increased risk of biochemical progression (p <0.001), which was somewhat but not completely attenuated by further adjusting for RP specimen pathological features (p = 0.03). Adjustment for surgeon did not affect these results. CONCLUSIONS: In men undergoing RP increased BMI was associated with adverse pathological features and a greater risk of biochemical progression. These findings together with the results of several recently published series collectively provide strong evidence that obese men undergoing RP are more likely to have aggressive prostate cancer.

Stronger association between obesity and biochemical progression after radical prostatectomy among men treated in the last 10 years.

BACKGROUND: Prior prospective cohort studies found that obesity was associated with increased risk of prostate cancer death. However, in the last 20 years dramatic changes in both the extent of obesity and prostate cancer screening and treatment have occurred. Whether the association between obesity and aggressive disease has changed as a result of these temporal changes is unclear. METHODS: The study population consisted of 2,832 men treated by anatomic radical retropubic prostatectomy between 1985 and 2004 by a single surgeon. We evaluated the associations of obesity (body mass index > or =30 kg/m(2))with tumor stage and grade using logistic regression and with biochemical progression using Cox proportional hazards regression. We examined whether these associations have changed over the last 20 years. RESULTS: On multivariable analysis, the strength of the positive association between obesity and high-grade disease increased over time whereas the strength of the positive association between obesity and positive surgical margins decreased over time. The strength of the positive association between obesity and extraprostatic extension fluctuated over time, although the strongest and only statistically significant association was among men treated since 2000. The association between obesity and biochemical progression was strongest among men treated since 1995 (relative risk, 1.90; 95% confidence interval, 1.09-3.30; P = 0.02). CONCLUSIONS: In the current study, with the exception of positive surgical margins, the positive association between obesity and high-grade disease, advanced stage, and biochemical progression after radical retropubic prostatectomy was in general strongest among men treated in the last 10 years. The reasons for these findings are not clear, although factors possibly related to prostate-specific antigen-based screening and/or other temporal changes in prostate cancer diagnosis and treatment may play a role.

Serum leptin and pathological findings at the time of radical prostatectomy.

PURPOSE: Obesity has been associated with a higher risk of progression following radical prostatectomy (RP). Obese men have higher serum leptin, a hormone produced by adipocytes, which has also been shown to be an in vitro prostate cancer growth factor. We examined whether serum leptin correlates with advanced pathological findings at RP. MATERIALS AND METHODS: Preoperative serum from 225 men treated with RP between 1998 and 1999 was examined for serum leptin. Multivariate logistic regression analysis was used to determine whether serum leptin was predictive of extraprostatic extension (pT3a). RESULTS: Serum leptin highly correlated with body mass index (Spearman r = 0.602, p <0.001). Serum leptin was not associated with total or percent free prostate specific antigen (PSA), biopsy or prostatectomy Gleason score, age or height. On multivariate analysis with total and percent free PSA, clinical stage, age, biopsy Gleason score, body mass index, serum leptin, and height as variables considered for entry into the model, serum PSA (p = 0.009), clinical stage (p = 0.019) and serum percent free PSA (p = 0.041) were the only variables predictive of extraprostatic extension. Serum leptin was not significantly associated with pathological stage (pT3a). CONCLUSIONS: In the current study of predominantly white men with mainly low risk disease there was no statistically significant association between serum leptin and pathological stage (pT3a) at RP. In this cohort serum leptin was not a good biomarker for predicting advanced stage at RP.