Long-term outcomes of children with Xp11.2 translocation renal cell carcinoma.

Abstract

9569 Background: We aimed to assess the clinico-pathological characteristics and the long-term prognosis of Xp11.2 translocation renal cell carcinoma (Xp-RCC) in children. Methods: A total of 52 Japanese children with renal tumors were presented to our institutions. Of these, 5 (10%) had RCC, and all RCCs were Xp11.2 translocation subtype with positive nuclear transcription factor E3 immunostaining. We retrospectively reviewed the pathological and hospital records of these 5 patients. Results: In the 1 boy and 4 girls with an average age of 9 years 7 months at diagnosis, the most common presenting complains were gross hematuria (60%) and palpable abdominal mass (40%). All patients had unilateral disease and there was no special family or medical history in any children. Computerized tomography revealed characteristic calcification within the tumor in 4 of the 5 patients (80%). In the remaining case, the lesion had high density areas with microcalcification, as confirmed by histopathological study. In 3 patients with regional lymph node metastasis, calcification was also observed in the metastatic lesions. Stage of the disease were stage I in 1 patient, II in 1, IV without and with distant metastasis in 2 and 1, respectively. All patients underwent transabdominal nephrectomy with regional lymphadenectomy. One patient with stage I disease had multiple metastases 15 months after surgery and died of disease in spite of interferon and chemotherapy 4 years postoperatively. Three patients received adjuvant interferon therapy and 2 of them are without evidence of recurrence postoperative 19 and 14 years, respectively. One of them had lymph node and lung metastases 12 years postoperatively. The remaining one patient had multiple lymph node, lung, bone, and dura mater metastases at diagnosis. The latter 2 patients have received targeted therapy (sunitinib, temsirolimus) without their progression for 6 and 12 months, respectively. Conclusions: Calcification within the tumor and/or metastatic lesions is characteristic findings suggestive of Xp-RCC in children. Regional lymphadenectomy or targeted therapy may provide some benefit in selected pediatric patients. Long-term follow-up is essential in pediatric patients with RCC.