Les carcinomes du rein à translocation de la famille MiT : histoire naturelle, caractéristiques moléculaire et prise en charge multidisciplinaire

Abstract : MiT family translocation renal cell carcinomas (tRCC) represent a rare subtype of renal cell carcinomas. These tumors have been introduced for the first time in the World Health Classification (WHO) classification of kidney cancers in 2004. tRCC are characterized by reccurent translocations involving members of the MiT family transcription factors, mainly TFE3 and TFEB. The estimated incidence of these tumors is ∼1-5 % among all renal cell carcinomas, with female prodominance. tRCC were initially described in children, and the spectrum has been expanded over time to encompass adolescents and adults. TFE3- and TFEB-rearranged RCC harbor characteristic clinicopathological and immunohistochemical features and fluorescent hybridization in situ is considered the gold standard for their diagnosis, although it has some limitations especially when the partners are located in the vicinity of TFE3. Nephron-sparing surgery is an efficient treatment of localized cases when achievable. In metastatic setting, targeted agents and immunotherapy showed modest efficacy, with response rates and median overall survival inferior to those observed in clear-cell renal cell carcinomas. Management of tRCC necessite a multidisciplinary team and accrual in clinical trials have to be encouraged when possible. Novel biological insights are urgently awaited to better understand the mechanisms associated with kidney oncogenesis in this setting, and ultimately help to identify therapeutic targets.