title: Impact of body mass index on clinicopathological outcome and biochemical recurrence after radical prostatectomy.
abstract: BACKGROUND
  Accumulating evidence suggests that obesity is associated with tumor progression in prostate cancer (PCa) patients after radical prostatectomy (RP). We conducted a retrospective multicenter study to determine the effect of body mass index (BMI) on the clinicopathological characteristics and biochemical recurrence of PCa in Japanese men who underwent RP.
  
  
  METHODS
  The medical records of 1257 men with PCa treated by RP without neoadjuvant therapy at four medical institutes between 2001 and 2009 were retrospectively reviewed. Patients were categorized into four groups using the World Health Organization (WHO) BMI classification and BMI quartiles. Associations of the various BMI categories with clinicopathological characteristics and biochemical recurrences were statistically evaluated. Biochemical recurrence was defined as a PSA level of >0.2 ng ml(-1).
  
  
  RESULTS
  Of the 1257 patients, 230 (18.3%) experienced biochemical recurrence during the median follow-up period of 49 months. The median BMI was 23.8 kg m(-2), and 1.4% patients were underweight, 65.4% were of normal weight, 30.9% were overweight and 2.4% were obese (WHO classification). Preoperative PSA levels and PSA density (PSAD) tended to decrease as BMI increased. Pathological characteristics did not differ significantly among BMI categories. As per the WHO classification and quartile categories, biochemical recurrence rate was comparable among the BMI groups. After adjusting for other pre- and postoperative covariables, multivariate Cox proportional hazards analysis revealed that a high BMI did not have an independent impact on biochemical recurrence-free survival.
  
  
  CONCLUSIONS
  Underweight Japanese PCa patients treated by RP had higher preoperative PSA levels and PSAD. High BMI was not associated with adverse pathological findings or increased biochemical recurrence rate in Japanese PCa patients treated with RP. Racial differences may exist in the relationship between obesity and outcomes of RP in PCa patients.
authors.affiliation: Department of Urology, Akita University School of Medicine, Akita, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Narita
authors.forename: K
authors.initials: K
authors.lastname: Mitsuzuka
authors.forename: T
authors.initials: T
authors.lastname: Yoneyama
authors.forename: N
authors.initials: N
authors.lastname: Tsuchiya
authors.forename: T
authors.initials: T
authors.lastname: Koie
authors.forename: N
authors.initials: N
authors.lastname: Kakoi
authors.forename: S
authors.initials: S
authors.lastname: Kawamura
authors.forename: Y
authors.initials: Y
authors.lastname: Kaiho
authors.forename: C
authors.initials: C
authors.lastname: Ohyama
authors.forename: T
authors.initials: T
authors.lastname: Tochigi
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: T
authors.initials: T
authors.lastname: Habuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Arai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D015992:Body Mass Index; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D009765:Obesity / Q000473:pathology*; D011379:Prognosis; D011467:Prostate / Q000187:drug effects / Q000473:pathology* / Q000601:surgery; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors