[size=6]A four-year-old girl is currently eighteen months off therapy for bilateral Wilms tumor. Previously she received neoadjuvant chemotherapy, bilateral partial nephrectomies and lymph node sampling, and bilateral flank radiation for positive lymph nodes. Her current off therapy scan reveals a 2 cm mass in the lower pole of the right kidney, distant from the renal vasculature and collecting system, no masses in the left kidney, and no lung lesions. What is the best next step in this child’s management?

 

a Radiation to right kidney

 

b Neoadjuvant chemotherapy

 

c Partial nephrectomy

 

d Radical nephrectomy

 

e Biopsy of renal mass[/size]

Biopsy of renal mass

D

correct answer

c Partial nephrectomy

 

This clinical scenario is most suggestive of recurrent disease in a child with previous bilateral Wilms tumors. In the initial setting of bilateral renal tumors suspected to be Wilms, according to the current Children’s Oncology Group (COG) guidelines, rather than proceed to biopsy or attempted resection, the most appropriate treatment is to initiate systemic chemotherapy. If the tumors fail to respond with a 50% reduction after six weeks, bilateral renal biopsy, because of 20% rate of tumor discordance, is required to define the pathology and adjust the chemotherapeutic regimen. Definitive surgery may be performed after six weeks but at the latest twelve weeks of neoadjuvant chemotherapy. The intent at surgical resection is to preserve as much renal parenchyma as possible. The procedure includes bilateral lymph node sampling. In the data published from the COG bilateral Wilms tumor study, rate of relapse following nephron-sparing surgery was 12%.

 

Continued attempts at preserving renal function are important, therefore avoiding nephrotoxic chemotherapy and additional radiation therapy are important. A partial nephrectomy, if possible, may be curative and could provide biology and histology data to guide choices for adjuvant therapy. In a report of repeat nephron-sparing surgery for recurrence in bilateral Wilms tumor, there were eight patients that underwent a repeat nephron-sparing surgery and two that had a third procedure. At an average followup of 4.5 years, six of these children were alive without disease.