Abstract 3525: Epidemiology and clinicopathology prognostic factors of TFEB translocation renal cell carcinoma (TBRCC): Analysis of updated pooled database

Renal cell carcinomas harboring the t(6;11) (p21;q12) translocation with a specific Alpha(MALAT1)-TFEB gene fusion is a recognized rare subtype of the Microphthalmia Transcription factor (MiT) family of translocation RCC. TBRCC is an indolent disease that occurs at a younger age. Though it may take on a wide spectrum of morphology, TBRCC has been classically characterized by distinctive biphasic morphology with larger epithelioid cells and smaller cells clustered around eosinophilic spheres formed by basement membrane material. This analysis was conducted to update and expand our existing knowledge of this rare disease. In order to study the demographic characteristics, cytogenetic and molecular signatures, survival, and prognostic factors, we compiled a pooled database of 140 cases. Kaplan-Meier survival curves were constructed. Cox proportional-hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on survival. The median age was 32 (3-78) years with a peak incidence between ages 17 and 30 years. Males and females were afflicted equally. The median overall survival (OS) of the whole group was not reached with more than 78% alive at 10 years. The group's median disease-free survival (DFS) was 96 months. Six percent of this cohort recurred. Among patients who recurred, the median time to recurrence was 24(6-75) months. Sex did not impact OS or DFS. Similarly, the molecular partner of the TFEB gene fusion, Alpha (MALAT1) versus others, did not seem to impact OS or DFS. The presence of necrosis seemed to adversely impact OS (HR:14.3, p