Does Preoperative Chemotherapy Ease the Surgical Procedure for Wilms Tumor?

Purpose: A conclusion of Societe Internationale d'Oncologie Pediatrique in 2001 after protocol 2, 5, 6, 9 and 93-01 was that "preoperative chemotherapy would make nephrectomy easier and furthermore, metastases may disappear or become resectable and vascular extension may regress and partial nephrectomy may become possible." We changed our strategy from preoperative chemotherapy in select cases only to standard 4 to 6-week preoperative chemotherapy in all. However, it appears dubious whether surgical ease or perioperative complications consistently improved after preoperative chemotherapy. We investigated volume changes after chemotherapy and compared all possible variables at a single center using the same surgical team. Materials and Methods: A total of 32 children with Wilms tumor between 1998 and 2007 were included in a retrospective analysis, including 15 without preoperative chemotherapy according to the National Wilms' Tumor Study Group protocol before 2001 and 17 with preoperative chemotherapy according to the Societe Internationale d'Oncologie Pediatrique 2001 protocol. We studied the change in tumor volume using picture archive and communication systems volume measurement after chemotherapy, surgical procedure parameters (child body mass index, length and type of incision, blood loss, operative time, hospital stay, pain medication and complications) and outcome (histology and staging). Statistical analysis was performed using the t, Fisher and chi-square tests. Results: The 2 groups were comparable in gender, age (mean 5.4 and 3.9 years, respectively) and staging at diagnosis. At diagnosis mean +/- SD Wilms tumor volume was 408.93 +/- 387.39 and 454.58 +/- 236.71 cm(3) in the nonchemotherapy and chemotherapy groups, respectively. In the chemotherapy group 12 of 17 tumors decreased a mean of 60.9% +/- 24.6% and 5 of 17 increased 42.8% +/- 31.3%. No analyzed parameters were different in the 2 groups. Conclusions: Our single center analysis with the same surgical team before and after the preoperative chemotherapy era show that it remains unpredictable whether surgery in a child with Wilms tumor is safer and easier after preoperative chemotherapy.