Abstract
BACKGROUND: Across multiple studies, obesity has been associated with an increased risk of higher grade disease and prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP). Whether these associations vary by race is unknown. In the current study, the authors examined the association between obesity and outcome after RP stratified by race. METHODS: A retrospective analysis was performed on 1415 men in the Shared Equal Access Regional Cancer Hospital (SEARCH) database who underwent RP between 1989 and 2008. The association between increased body mass index (BMI) and adverse pathology and biochemical recurrence was examined using multivariate logistic regression and Cox models, respectively. Data were examined stratified by race. RESULTS: After adjusting for preoperative clinical characteristics, higher BMI was associated with higher tumor grade (P = .008) and positive surgical margins (P < .001) in white men, and similar but statistically nonsignificant trends were observed in black men. No significant interaction was noted between race and BMI for associations with adverse pathology (P(interaction)> or =.12). After adjusting for preoperative clinical characteristics, higher BMI was associated with an increased risk of recurrence in both white men (P = .001) and black men (P = .03). After further adjusting for pathologic variables, higher BMI was associated with significantly increased risk of recurrence in white men (P = .002) and black men (P = .01). No significant interactions were observed between race and BMI for predicting biochemical progression adjusting either for preoperative factors (P(interaction) = .35) or for preoperative and pathologic features (P(interaction) = .47). CONCLUSIONS: Obesity was associated with a greater risk of recurrence among both black men and white men. Obesity did not appear to be more or less influential in 1 race than another but, rather, was identified as a risk factor for aggressive cancer regardless of race.