Background: Wilms’ tumor is the most common malignant renal tumor in children. Nephrectomy has played a central role in the treatment of Wilms’ tumor, but some advanced Wilms’ tumors could not be resected immediately because of massive tumor size, involvement of vital structures, inferior vena cava invasion or distal metastasis. To improve the prognosis of patients with these inoperable Wilms’ tumors, we used preoperative chemotherapy and transcatheter arterial chemoembolization (TACE) before surgery. The aim of this study was to investigate the effectiveness of preoperative therapy and to compare it with the strategy of immediate surgery.

Methods: Sixty-two patients with histologically confirmed advanced Wilms’ tumor aged from 5 months to 10 years (mean 3.2 years) were identified from case records during the period from January 1993 to December 2002. The inclusion criteria included a volume of more than 550 ml or the mass extending beyond the midline, involvement of vital structures, inferior vena cava invasion, distal metastasis or bilateral Wilms’ tumor judged by imaging studies. The patients were treated with the following 3 methods separatelly: (1) TACE with epirubicin (EPI)-lipiodol emulsion and two-week systemic chemotherapy with vincristine (VCR) and actinomycin D (ACTD) before surgery (group TACE) (31 patients); (2) conventional systemic preoperative chemotherapy with VCR, ACTD plus EPI for 4-5 weeks (group PC) (20); and (3) initial surgery (group IS) (11). In the three groups, stage II-III was present in 22 (71%), 16 (80%) and 9 (82%) patients; stage III in 5 (16%), 4 (20%) and 2 (18%); stage IV in 3 (10%), 0 and 0; and stage V in 1 (3%), 0 and 0, respectively. Unfavorable histology was found in 2, 1 and 1 patients in the three groups, respectively. Postoperative treatment for all patients was based on the postoperative stage and histology of tumors. Tumor shrinkage before operation, cases of total tumor necrosis, rate of no tumor rupture during operation, and 2-year and 4-year survival rates were compared among the 3 groups.

Results: In the patients treated with TACE, no drug-induced complications including cardiotoxicity, nephrotoxicity, hepatic dysfunction or bone marrow suppression were observed except for mild fever caused by tumor necrosis. Pulmonary metastases on CT disappeared in 2 of 3 patients after TACE with short-term systemic chemotherapy. The percentages of tumor size shrinkage were 32.4% and 20.3% in group TACE and group PC, respectively. No perioperative death occurred in group TACE and group PC, but two in group IS. In group TACE, only 6.5% patients experienced tumor rupture during operation in comparison with 20.0% in group PC and 45.5% in group IS. Complete surgical removal of the tumor was achieved in 27 patients (87.1%) in group TACE, significantly higher in comparison with 14 (70.0%) in group PC and 2 (18.2%) in group IS. Event-free survival (EFS) at 2 and 4 years were 87.1% (27/31) and 84.5% (11/13) in group TACE, 60.0% (12/20) and 56.3% (9/16) in group PC, 18.2% (2/11) and 18.2% (2/11) in group IS, respectively.

Conclusions: This study has shown that both preoperative TACE and conventional preoperative chemotherapy can be applied to properly selected patients with inoperable Wilms’ tumor who are not candidates for immediate surgery. The survival rate is significantly increased in the patients undergoing preoperative TACE and short-term systemic chemotherapy compared with conventional preoperative chemotherapy and initial surgery in the same period. TACE is an effective, safe, and useful method for the initial treatment of inoperable Wilms’ tumor.