Xp11.2 Translocation Renal Cell Carcinoma: Clinical Characteristics and Potential Prognostic Predictors

Abstract

Background. Xp11.2 translocation renal cell carcinoma, a rare malignancy, has a higher prevalence in children than in adults. It is relatively indolent in children but manifests with an aggressive course in adults. Clinical characteristics and prognostic studies for adult patients are scarce due to its rarity. Methods. This retrospective single-center study consecutively enrolled 24 newly diagnosed Xp11.2 translocation RCC adult patients. Clinical presentations were recorded, and baseline laboratory results and follow-up data were collected. Possible risk factors for progression-free survival and overall survival were first scanned with chi-square tests and $t$ -tests to compare patients who suffered from progression or death with who did not. Multivariate Cox regression was further utilized to identify independent risk factors. Results. Twenty-four adult patients (median age 32, range 16-73), with a male-to-female ratio of 1 : 1, was included from April 2010 to March 2020. After follow-up for 35.7 months (+/- months), seven patients died. With univariate analysis, higher C-reactive protein-to-albumin (CRP/Alb) ratio ( $p=0.028$ ), higher baseline fibrinogen ( $p=0.006$ ), and presence of distant metastasis ( $p=0.007$ ) were associated with progression of the disease; higher preoperative fibrinogen ( $p=0.014$ ) and distant metastasis ( $p=0.020$ ) were associated with death. With multivariate Cox regression, only baseline fibrinogen level ( $p=0.001$ ) was identified as an independent risk factor for progression-free survival; meanwhile, fibrinogen level ( $p=0.048$ ) and distant metastasis ( $p=0.043$ ) were identified as independent risk factors for survival. Conclusions. Overall, relatively high CRP/Alb ratios, fibrinogen, and distant metastasis were associated with a poor prognosis of Xp11.2 tRCC adult patients; among them, only baseline fibrinogen levels independently predicted the progression of Xp11.2 tRCC; thus, it may help to identify patients with worse progression or death risk.