[Is sarcopenia a morbi-mortality factor in the treatment of localized muscle-invasive bladder cancer?] / La sarcopénie est-elle un facteur de morbi-mortalité dans le traitement des tumeurs localisées de la vessie infiltrant le muscle ?

INTRODUCTION: Sarcopenia evaluated from the measurement of skeletal muscle index (SMI) has been evaluated as a predictive factor of morbidity and mortality after surgery. The objective of this study was to evaluate whether it was predictive of morbidity and mortality in patients managed by cystectomy or tri-modality therapy (TMT), combining radiotherapy and chemotherapy after endoscopic resection of the tumour, for localized muscle-invasive bladder cancer. MATERIALS AND METHODS: In all, 146 consecutive patients from 2 university hospital centres treated by cystectomy between January 2012 and April 2017 or TMT between October 2008 and October 2014 were included. The SMI was measured on axial computed-tomography at the level of the transverse process of L3, before treatment. Sarcopenia was assessed in two ways: either by SMI without muscle mass adjustment or according to the definition by Martin and al. based on gender and patient BMI, then called "adjusted sarcopenia". The primary endpoint was overall survival (OS) for sarcopenia. The secondary endpoints were OS, progression-free survival (PFS) and survival without re-admission (SRH) for the total population and for each treatment group. Survival analyses were performed using the Cox model. The association between sarcopenia and complications has been investigated by the Chi2 test. RESULTS: The characteristics of sarcopenic (n=67) and non-sarcopenic (n=79) patients were comparable except for 2 criteria: older patients in the sarcopenic group and a higher proportion of neo-adjuvant chemotherapy in non-sarcopenic patients. Sarcopenia was not significantly associated with any type of survival. Sarcopenia was not associated with the proportion or severity of complications. CONCLUSION: Unlike unadjusted SMI, sarcopenia was not associated with survival or complications. LEVEL OF EVIDENCE: 3.