Transcription factor E3 and transcription factor EB renal cell carcinomas: clinical features, biological behavior and prognostic factors.

PURPOSE: Translocation renal cell carcinomas represent a distinct clinicopathological entity. Studying the natural history, biological behavior and potential prognostic factors are crucially warranted.
MATERIALS AND METHODS: We selected 54 patients with renal cell carcinoma with positive nuclear transcription factor E3 and transcription factor EB expression from the Juvenile RCC Network. Recurrence-free survival and overall survival were assessed.
RESULTS: Median patient age was 24 years (range 1 to 64) and the male-to-female ratio was 1:1.4. At diagnosis 35 patients (65%) had local disease while 19 (35%) presented with distant metastases. The latter patients were older (median age 36 years) and predominantly male (male-to-female ratio 2) whereas the former group had a median age of 16 years and a male-to-female ratio of 1:2.5. Overall 36 patients underwent complete tumor resection and of these 8 had recurring cancer. On univariate analysis only lymph node involvement and American Joint Committee on Cancer stage were associated with poor recurrence-free survival. When stratified according to lymph node status age 25 years or older was found to predict relapse (p = 0.03). With a median followup of 19.2 months (range 1 to 58) 3-year overall survival was 14.3% in patients with distant metastasis and 70.6% in those without distant metastasis. Distant metastasis developed in the 2 patients with ASPSCR1-TFE3 fusion vs 1 of 11 with other fusion genes.
CONCLUSIONS: Transcription factor E3 and transcription factor EB renal cell carcinoma display different clinical behavior according to gender and age. Lymph node involvement represents the only factor that predicts recurrence. ASPSCR1-TFE3 might be the most aggressive among the transcription factor E3 fusion genes.