title: Bimodal pattern of the impact of body mass index on cancer-specific survival of upper urinary tract urothelial carcinoma patients.
abstract: OBJECTIVE
  To clarify how body mass index (BMI) affects the risk of death from upper urinary tract urothelial carcinoma (UUTUC) we investigated the impact of BMI on UUTUC using a Japanese multicenter database.
  
  
  METHODS
  Between January 1995 and December 2010, 1,329 patients with upper urinary tract tumors were treated in 13 institutions in Japan. From this group, a cohort of 1,014 patients treated with radical nephroureterectomy was retrospectively reviewed. BMI was categorized into the following three groups: BMI <22.5, BMI 22.5 to <25 and BMI ≥ 25. The association between each group and cancer-specific survival (CSS) was analyzed using Cox proportional hazards regression models.
  
  
  RESULTS
  The median BMI was 22.4 kg/m(2) (interquartile range, 20.5-24.8). Out of all patients, 213 (21%) died of UUTUC. Hazard ratios of the BMI ≥ 25 and the BMI <22.5 group were 1.76 and 1.66, respectively.
  
  
  CONCLUSIONS
  Both higher and lower BMI affect the prognosis of UUTUC treated with radical nephroureterectomy.
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan ishiuro@tmd.ac.jp.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Ishioka
authors.affiliation: Department of Urology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Masuda
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Kijima
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Tatokoro
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Minato
authors.initials: M
authors.lastname: Yokoyama
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Matsuoka
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Numao
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Koga
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Saito
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujii
authors.affiliation: Department of Urology, National Cancer Center Hospital East, Chiba, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Department of Urology, East Tokyo Metropolitan Hospital, Tokyo, Japan.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Arisawa
authors.affiliation: Department of Urology, JA Toride Medical Center, Ibaraki, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Okuno
authors.affiliation: Department of Urology, Kounodai Hospital, National Center for Global Health and Medicine, Chiba, Japan.
authors.forename: Katsuhi
authors.initials: K
authors.lastname: Nagahama
authors.affiliation: Department of Urology, Soka Municipal Hospital, Saitama, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Kamata
authors.affiliation: Department of Urology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Yonese
authors.affiliation: Department of Urology Saitama Cancer Center, Saitama, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kageyama
authors.affiliation: Department of Urology, Saitama Red Cross Hospital, Saitama, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Noro
authors.affiliation: Department of Urology, Tsuchiura Kyodo General Hospital, Ibaraki, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Morimoto
authors.affiliation: Department of Urology, Tokyo Metropolitan Ohtsuka Hospital, Tokyo, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tsujii
authors.affiliation: Department of Urology, Tama-Nanbu Chiiki Hospital, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kitahara
authors.affiliation: Department of Urology, Hamamatsu Medical Center, Shizuoka, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Gotoh
authors.affiliation: Department of Urology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kihara
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012307:Risk Factors; D014571:Urologic Neoplasms / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality*
keywords: Upper tract urothelial carcinoma; body mass index; obesity; sex difference