PREOPERATIVE THERAPY FOR INTRACAVAL AND ATRIAL EXTENSION OF WILMS-TUMOR

Background. Primary surgical management of Wilms tumor with intravascular tumor extension is associated with significant morbidity. Retrospective analysis of a group of Wilms tumor patients with intravascular tumor extension treated with preoperative therapy was performed to evaluate the feasibility of this approach. Methods. Thirty children with caval (15 patients) or atrial (15 patients) extension of Wilms tumor who received preoperative therapy were reviewed. Patients were classified according to the stage of the disease as follows: (1) Stage III, 7 patients; (2) Stage IV, 18 patients; and (3) Stage V, 5 patients. The histologic type was favorable in 20 patients, anaplastic Wilms tumor in 7, and unknown in 3. All of the children received preoperative chemotherapy, ranging from 1-16 weeks with an average of 7.2 weeks. Results. One child died of progressive disease and another from toxicity before surgery. In 23 patients, a decrease in the size of the intravascular extension was noted preoperatively, without tumor embolization in any case. There was complete resolution of tumor thrombus in seven patients. Two-year survival for the entire group is 70%, with a median follow-up period of 21 months. Conclusions. The use of preoperative therapy is appropriate in selected patients with extensive intravascular tumor involvement. Surgical management was facilitated in the majority of cases due to shrinkage of the primary tumor and reduction in the size of the tumor thrombus.