The role of surgery in stage IV neuroblastoma.
BACKGROUND/PURPOSE: The importance of primary tumor resection in stage IV neuroblastoma is controversial. The authors analyzed prospectively the role of surgery in a multicentric series of stage IV neuroblastoma patients. METHODS: Patients were studied according to the International Neuroblastoma Staging System (INSS) recommendations. Age, sex, location of the tumor, type of metastases, time of resection (initial or delayed), extension of resection, surgical complications, pathology, N-myc and Shimada classification results, relapses, and outcome were studied. After diagnosis, children received induction chemotherapy followed by delayed surgery and autologous stem cell transplantation or maintenance chemotherapy. Resection was classified as complete (C), greater than 90% (P1), greater than 50% (P2), less than 50% (P3), and biopsy (B). RESULTS: Ninety-eight stage IV children were admitted in the study from June 1992 to July 1999. Seventy-six were older than one year, and in 78 the primary tumor was abdominal. Bone was the most common metastatic site followed by bone marrow. Initial biopsy was performed in 74 patients, and resection in 6, with one complication in each group. N-myc was amplified in 20 of 80 tumors, and Shimada was unfavorable in 45 of 67. Delayed surgery was performed in 70 cases, achieving gross total resection in 55 (79%); there were minor complications in 10%. Mean survival rate time was 50 months. Event-free survival rate (EFS) at 5 years for the entire series is 0.32, but 0.0 for children having biopsy only, 0.25 for less than 50% resection, 0.31 for 50% to 90% resection, 0.44 for greater than 90% resection, and 0.33 for complete resection. Differences were statistically significant only when compared with the biopsied group. EFS rate for infants was 0.56, but, again, there was no difference in relation to the type of resection. There were 46 relapses, 12 of them local, 7 of 20 N-myc-amplified tumors, and 4 of 60 not amplified (P <.005). CONCLUSIONS: Biopsies of stage IV neuroblastoma allow safe assessment of N-myc and other biological factors on tumor tissue. Delayed surgery after chemotherapy is performed with a low rate of complications, achieving a good local control of disease. N-myc-amplified tumors have higher local relapse rates than nonamplified and therefore would need more intensive local treatment. The final outcome in these patients is determined more by metastatic relapses than by the degree of resection.