title: Overweight in adolescence is related to increased risk of future urothelial cancer.
abstract: Obesity has been linked to various malignancies, but a clear relation of overweight with urothelial cancer has not been established. We assessed the association between adolescent obesity and future risk for urothelial cancer. Medical data on 1,110,835 Israeli adolescents examined for fitness for military duty between 1967 and 2005 were linked to the National Cancer Registry in this nationwide population-based cohort study. We used Cox proportional hazards modeling to estimate the covariate-adjusted hazard ratio (HR) for urothelial cancer associated with BMI measured at age 17. The mean follow-up of 17.6 ± 10.8 years reflected 19,576,635 person years, during which 661 examinees developed urothelial cancer of the bladder, ureter, or renal pelvis. BMI ≥ 85 th standard percentile in adolescence significantly predicted increased risk of urothelial cancer with a HR (adjusted for year of birth, education and religiosity) of 1.42 (95% confidence interval (CI), 1.13-1.77, P = 0.002). Similar results were observed using the ≥ 25 kg/m(2) definition of overweight (HR = 1.36 (95% CI, 1.08-1.72), P = 0.008). Incidence of urothelial cancer was significantly lower in the more educated and among those who attended religious schools. Overweight in adolescence is related to increased risk of future urothelial cancer. In view of the growing incidence of both urothelial cancer and adolescent obesity, our study suggests an avenue for possible prevention of urothelial cancer.
authors.affiliation: Medical Corps, Israeli Defense Force, Tel Aviv, Israel. aleiba@mah.harvard.edu
authors.forename: Adi
authors.initials: A
authors.lastname: Leiba
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Kark
authors.forename: Arnon
authors.initials: A
authors.lastname: Afek
authors.forename: Zohar
authors.initials: Z
authors.lastname: Levi
authors.forename: Micha
authors.initials: M
authors.lastname: Barchana
authors.forename: Dorit
authors.initials: D
authors.lastname: Tzur
authors.forename: Estela
authors.initials: E
authors.lastname: Derazne
authors.forename: Asaf
authors.initials: A
authors.lastname: Vivante
authors.forename: Ari
authors.initials: A
authors.lastname: Shamiss
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002295:Carcinoma, Transitional Cell / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012307:Risk Factors; D017678:Sex Distribution; D014565:Urogenital Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control