title: Body mass index and survival in patients with renal cell carcinoma: a clinical-based cohort and meta-analysis.
abstract: Growing evidence suggests that obesity, an established cause of renal cell cancer (RCC), may also be associated with a better prognosis. To evaluate the association between RCC survival and obesity, we analyzed a large cohort of patients with RCC and undertook a meta-analysis of the published evidence. We collected clinical and pathologic data from 1,543 patients who underwent nephrectomy for RCC between 1994 and 2008 with complete follow-up through 2008. Patients were grouped according to BMI (kg/m(2) ): underweight <18.5, normal weight 18.5 to <23, overweight 23 to <25 and obese ≥25. We estimated survival using the Kaplan-Meier method and Cox proportional hazard models to examine the impact of BMI on overall survival (OS) and cancer-specific survival (CSS) with adjustment for covariates. We performed a meta-analysis of BMI and OS, CSS and recurrence-free survival (RFS) from all relevant studies using a random-effects model. The 5-year CSS increased from 76.1% in the lowest to 92.7% in the highest BMI category. A multivariate analysis showed higher OS [hazard ratio (HR) = 0.45; 95% CI: 0.29-0.68) and CSS (HR = 0.47; 95% CI: 0.29-0.77] in obese patients than in normal weight patients. The meta-analysis further corroborated that high BMI significantly improved OS (HR = 0.57; 95% CI: 0.43-0.76), CSS (HR = 0.59; 95% CI: 0.48-0.74) and RFS (HR = 0.49; 95% CI: 0.30-0.81). Our study shows that preoperative BMI is an independent prognostic indicator for survival among patients with RCC.
authors.affiliation: Women's Health Research Institute, Sookmyung Women's University, Seoul, Republic of Korea.
authors.forename: Yuni
authors.initials: Y
authors.lastname: Choi
authors.forename: Bumsoo
authors.initials: B
authors.lastname: Park
authors.forename: Byong Chang
authors.initials: BC
authors.lastname: Jeong
authors.forename: Seong Il
authors.initials: SI
authors.lastname: Seo
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Jeon
authors.forename: Han Yong
authors.initials: HY
authors.lastname: Choi
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Hyun Moo
authors.initials: HM
authors.lastname: Lee
mesh_terms: D015992:Body Mass Index; D002292:Carcinoma, Renal Cell / Q000150:complications / Q000401:mortality*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000150:complications / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D016016:Proportional Hazards Models