Observation without surgery for localized, suspected adrenal neuroblastoma in infants
Studies suggest that selected presumed neuroblastomas detected in infants by screening or incidental ultrasound may safely be observed without obtaining a definitive histologic diagnosis and without surgical intervention, thus avoiding potential complications of surgery in the newborn.[4,5,6] The experience with tumors detected by mass urinary catecholamine metabolite screening in Japan appears to be applicable to tumors detected by prenatal or perinatal ultrasound in the United States. The COG is investigating systematic observation without surgery for infants with presumed small Evans stage I adrenal neuroblastoma detected by prenatal or perinatal ultrasound.
Patients categorized as intermediate risk (refer to Table 1 in the Stage Information section of this summary) have been successfully treated with surgery and 12 to 24 weeks of the same chemotherapy regimen described above (COG-A3961). As a rule, patients whose tumors have unfavorable biology receive twice as many cycles of chemotherapy as those with favorable biology.
Whether initial chemotherapy is indicated for all intermediate-risk infants with localized neuroblastoma is controversial. A German prospective clinical trial enrolled 340 infants aged 1 year or younger whose tumors were stage 1, 2, or 3, histologically verified, and lacked MYCN amplification. Forty-four of 93 infants with unresected tumors experienced spontaneous regression (17 were complete regressions) and 39 infants experienced progression. The 3-year overall survival (OS) rate was 99%, and the metastases-free survival rate was 94% for infants with unresected tumors and was not different from infants treated with surgery or chemotherapy (median follow-up, 58 months). The investigators suggested that a wait-and-see strategy is appropriate for infants with localized neuroblastoma because regressions have been observed after the first year of life.
Moderate-dose chemotherapy has been shown to be effective in the prospective Infant Neuroblastoma European Study (INES 99.1 [EURO-INF-NB-STUDY-1999-99.1]), where about half of the infants with unresectable, nonmetastatic neuroblastoma and no MYCN amplification underwent a safe surgical resection and avoided long-term adverse effects. The 5-year OS rate was 99% and the event-free survival (EFS) rate was 90% (median follow-up, 6 years). In this study, infants undergoing surgical resection had a better EFS than those who did not have surgery.[Level of evidence: 3iiA]
In contrast, patients categorized as high risk (refer to Table 1 of the Stage Information section of the summary) are generally treated with dose-intensive multiagent chemotherapy consisting of very high doses of the drugs listed above but often also including ifosfamide and high-dose cisplatin. After a response to chemotherapy, resection of the primary tumor should be attempted, followed by myeloablative chemotherapy and autologous stem cell transplantation. Radiation of residual tumor and original sites of metastases is often performed before, during, or after myeloablative therapy. After recovery, patients are treated with oral 13-cis -retinoic acid for 6 months. Both myeloablative therapy and retinoic acid improve outcome in patients categorized as high risk.[8,9]; [Level of evidence: 1iiA] Compared to retinoic acid alone, chimeric anti-GD2 antibody ch14.18 combined with granulocyte macrophage-colony stimulating factor and interleukin-2 and given in concert with retinoic acid improves event-free survival for high-risk neuroblastoma patients in remission after stem cell transplant.