Prognostic value of perirenal and/or sinus fat infiltration in patients with pT3a renal cell carcinoma: A multicentre cohort study. LARCG Group. / Valor pronóstico de la invasión de grasa perirrenal y/o del seno en pacientes con carcinoma de células renales pT3a: estudio de cohorte multicéntrico. Grupo LARCG.

INTRODUCTION AND OBJECTIVES: The objective of this study is to evaluate overall survival (OS), cancer-specific survival (CSS), relapse-free survival, local and distant (LRFS and DRFS, respectively) rates in patients with pT3a renal cell carcinoma (RCC) considering the perirenal and/or sinus fat infiltration (FI) as prognostic factors. MATERIALS AND METHODS: Retrospective cohort of patients with pT3a RCC who underwent radical or partial nephrectomy. The data were extracted from the LARCG (Latin American Renal Cancer Group) database. The demographic, clinical, pathological and surgical variables were evaluated. FI was divided into 4 groups (vein, perirenal, sinus and both fats infiltration). The Kaplan Meier and Cox regression curves were performed. RESULTS: 293 patients were included in the study. The mean age was 61.4 years. The median follow-up was 21 months (r: 1-194). CSS, RFS, LRFS and DRFS estimated at 3 years in the group of both fats' infiltration were 53.1, 45.1, 58.7 and 51.6 months, respectively, and always statistically lower than the rest (P˂0.005). In the multivariate analysis, the infiltration of both fats significantly increased specific mortality, overall and local relapse with respect to vein infiltration (HR: 4.5, 2.42 and 8.08, respectively). The Fuhrman grade and renal pelvis infiltration were independent predictors of CSS and RFS. CONCLUSIONS: Infiltration of both fats increases the risk of overall and local relapse in pT3a RCC. In the same way, it is associated with a lower cancer-specific survival and should be considered as a factor of poor prognosis.