Body mass index and survival in patients with renal cell carcinoma: a clinical-based cohort and meta-analysis

A partir d'une revue de la littérature et des données d'une cohorte incluant 1 543 participants, cette méta-analyse évalue l'impact de l'obésité sur la survie des patients atteints d'un carcinome à cellules rénales

Résumé en anglais

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/m2): 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 to 0.68) and CSS (HR = 0.47; 95% CI: 0.29 to 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 to 0.76), CSS (HR = 0.59; 95% CI: 0.48 to 0.74), and RFS (HR = 0.49; 95% CI: 0.30 to 0.81). Our study shows that preoperative BMI is an independent prognostic indicator for survival among patients with RCC.