ClinicalNephron-sparing surgery in the treatment of pediatric renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusions

PurposeTo investigate the safety and efficacy of nephron-sparing surgery (NSS) in the treatment of pediatric Xp11.2 translocation renal cell carcinoma (RCC).MethodsClinical characteristics of 9 RCC children (7 males and 2 females) with Xp11.2 translocation who received NSS between January 1973 and December 2015 were retrospectively analyzed. The mean age was 7.8 years (range: 4.5-13.5 years). Xp11.2 translocation RCC was found in the left side in 4 patients and right in 5. 3 tumors were located in the upper pole of the kidney, 1 in the middle dorsal, 1 in the middle ventral and 4 in the lower pole. RCC presented with painless gross hematuria in 4 patients, abdominal mass in 1, and as an incidental finding by ultrasound examination in 4 patients. The mean course of hematuria was 3 months (range: 1-7 months). The mean tumor diameters were 3.7 cm (range: 2.2-6.9 cm).ResultsAll the patients received NSS with open transperitoneal approach. The mean operative time and estimated blood loss were 115 min and 40 ml, respectively. The time of renal pedicle clamping was 19-25 min (mean: 21.5 min). No complications (such as leakage of urine, prolonged drainage or secondary bleeding) were noted. No patients experienced local recurrence during the mean of 50.1-month follow-up (range: 13-117 months). Intravenous urography (IVU) or contrast-enhanced CT was conducted at 6 months after surgery which showed favorable kidney function in all patients.ConclusionXp11.2 translocation RCC is a predominant pathological but biologically inert type of pediatric RCC. For Xp11.2 translocation RCC sized < 4-7 cm in diameter and located in one pole, NSS is safe and feasible.Type of studyTreatment Studies, LEVEL IV.