Initial surgical intervention for pediatric renal tumors

Abstract

In the treatment of patients with Wilms tumor, the National Wilms Tumor Study Group (NWTS) in the USA follows the upfront surgery principle, whereas the SIOP in Europe follows the upfront chemotherapy principle in all stages of the disease. In Japan, the Wilms Tumor Study Group (JWiTS) follows the upfront surgery principle. The advantage of upfront surgery is that accurate surgical and pathological diagnoses enable the risk classification and help in choosing the suitable postoperative treatments. On the other hand, the advantage of upfront chemotherapy is that the reduction in tumor size will reduce the surgical risk, and the downgrading of the stage of the disease may result in the omission of doxorubicin and radiotherapy. Upfront chemotherapy also enables the effects of chemotherapy to be confirmed. In the NETS staging system, the patients who underwent tumor biopsy (open or needle) became stage III, whereas in the SIOP staging system, the patients who underwent needle biopsy did not become stage III. In the JWiTS-2 study, tumor spillage was responsible for most of the stage III cases. Therefore, if they were treated with the upfront chemotherapy principle, the reduction in tumor size might have reduced the surgical risk and the tumor had been resected without spillage.