Impact of obesity on prostate cancer recurrence after radical prostatectomy: data from CaPSURE.

OBJECTIVES: To determine the association between obesity and prostate cancer recurrence after primary treatment with radical prostatectomy.
METHODS: Data were abstracted from CaPSURE, a disease registry of 10,018 men with prostate cancer. We included 2131 men who had undergone radical prostatectomy between 1989 and 2003 and had body mass index (BMI) information available. Recurrence was defined as two consecutive prostate-specific antigen (PSA) levels of 0.2 ng/mL or greater or any second treatment. Patients were risk stratified using the PSA level, Gleason grade, and clinical T stage.
RESULTS: Patients were followed up for a median of 23 months. Of the 2131 patients, 251 (12%) developed recurrence at a median of 13 months (range 1 to 107); 183 (9%) of these men had PSA failure and 68 (3%) received a second treatment. After adjusting for risk group, ethnicity, age, and comorbidities, a significant association was found between an increasing BMI and disease recurrence (P = 0.028). Very obese patients (BMI 35 kg/m2 or more) were 1.69 times more likely to have recurrence relative to men of normal weight (BMI less than 25.0 kg/m2; 95% confidence interval [CI] 1.01 to 2.84). An increasing PSA level (P <0.0001) and Gleason grade (P <0.0001) were also associated with recurrence. Ethnicity was not significantly associated with either BMI or PSA recurrence (P = 0.685 and P = 0.068, respectively).
CONCLUSIONS: The results of our study have shown that obesity is an independent predictor of prostate cancer recurrence. Because of the increased comorbidities and greater rates of recurrence, obese individuals undergoing radical prostatectomy need vigilant follow-up care.