Overweight and obesity as risk factors for biochemical recurrence of prostate cancer after radical prostatectomy

Background Previous studies have shown a relationship between the occurrence and recurrence of prostate cancer; however, this relationship remains controversial. We investigated the relationship between obesity and biochemical recurrence in patients with prostate cancer. Methods Clinicopathological factors were analyzed after dividing the patient population according to the Asian population-specific body mass index (BMI) criteria for "normal" (< 23 kg/m(2)), "overweight" (23-27.5 kg/m(2)), and "obese" (>= 27.5 kg/m(2)). Among the 389 patients included in this study, 108 were classified as normal, while 227 and 54 patients were classified as overweight and obese, respectively. The relationships between clinicopathological factors and biochemical recurrence were analyzed by univariate and multivariate Cox <= proportional hazard models. Biochemical recurrence was defined as two consecutive prostate-specific antigen (PSA) measurements >= 0.2 ng/mL. Results In univariate analysis, the categorical variables of "overweight" and "obese" were significant prognostic factors for biochemical recurrence. In multivariate analysis models including PSA density [hazard ratio (HR) 1.8, p = 0.01], extraprostatic extension (HR 2.0, p < 0.001), Gleason score (HR 1.7, p = 0.01), surgical margin positivity (HR 2.46, p < 0.001), and lymphovascular invasion (HR 2.53, p < 0.001), the categorical variables of "overweight" (HR 1.6, p = 0.03) and "obese" (HR 1.76, p = 0.035) were prognostic factors for biochemical recurrence. Conclusion The obesity status of patients with prostate cancer as "overweight" and "obese" was a risk factor for biochemical recurrence after adjusting for other clinicopathological factors.