Surgical complications in the treatment of Wilms' tumor.

We present our data on the treatment of Wilms' Tumor (WT) with an emphasis on both the positive effect and the adverse effect of preoperative chemotherapy with regard to surgical intervention. From 1980 to 2000 70 children were treated. 57 % received preoperative chemotherapy (ChTx) and 43 % were operated on primarily. 75 % of the tumors responded to ChTx with significant shrinkage of the size. After preoperative ChTx 54 % of the cases were regrouped as stage I, whereas after primary operation 46 % of the patients were grouped as stage I, thus indicating a downstaging with preoperative ChTx. In 8 % of the patients with preoperative chemotherapy intraoperative complications occurred with a rupture of the tumor in 1 case. In contrast, there were intraoperative complications in 25 % of the patients with a primary operation with rupture of the tumor in 3 cases. 1 child (1.5 %) was treated with chemotherapy who did not have a Wilms' tumor but a benign nephroma (CMN). 3 cases had a clear cell sarcoma (CCSK) and in one case histology revealed a rhabdoid tumor (MRTK). In one case of CCSK only histology of the metastases disclosed the correct diagnosis. The rate of postoperative complications such as ileus was the same for both groups. Irrespective of the known adverse effects such as changing tumor histology, which may affect the correct staging, and the remaining risk of an initial inadequate treatment, our data show that the regimen of preoperative chemotherapy as proposed by the SIOP study should not be abandoned. However, the relatively small number of our patients does not allow a significant statement to be made but confirms the results of past SIOP studies.