Surgical aspects of N-myc oncogene amplification of neuroblastoma

The surgical aspects of N-myc oncogene amplification of neuroblastic tumors were studied in 42 patients with ganglioneuroblastoma or neuroblastoma. The cumulative survival rate of patients with fewer than 10 copies of N-myc (L group) was 73.7% 48 months after initiation of therapy, whereas the rate for those with more than 10 copies of N-myc (H group) was 0% by 20 months (P less than 0.000001). Clinical prognostic factors of neuroblastic tumors such as age, stage, histologic findings, and primary site correlated with the amplification of N-myc. N-myc amplification of more than 10 copies was evident in one of 16 (6.3%) patients less than 1 year of age and in 13 of 26 (50%) patients over 1 year of age and was detected in one of six tumors in stage II, four of 10 in stage III, seven of 16 in stage IV, and two of six in stage IV-S. The amplification occurred more frequently in patients with neuroblastoma than in those with ganglioneuroblastoma and was observed only in tumors of a suprarenal region. Preoperative chemotherapy was prescribed for 19 of the 26 patients with stage III or IV tumors and was similarly effective in both L and H groups. Ipsilateral nephrectomy or combined resection of a part of liver had to be performed in nine of 11 (82%) patients with stage III or IV tumors in the H group but in only one of 15 (6.7%) in the L group, thereby suggesting that the tumor with an amplified N-myc is more invasive. In patients in the advanced stage, total or nontotal resection of the tumor did not affect the survival in the L group, but the survival interval was prolonged significantly by the total removal of the tumor in patients in the H group. These data should aid in the surgical treatment of patients with poor-prognostic neuroblastoma and an amplified N-myc oncogene.