Purpose: To define factors that influence outcome in children with localized but unresectable neuroblastoma by retrospective investigation of response to therapy and outcome in 21 Italian institutions.
Patients and methods: Of 145 assessable children diagnosed between 1979 and 1990, 77 were treated between 1979 and 1984 with three consecutive standard-dose (SD) protocols, and 68 between 1985 and 1990 with a high-dose (HD) protocol. All protocols included chemotherapy, followed by resection of primary tumor if feasible. If at least partial resection was achieved, consolidation therapy followed, except that from 1985 onward, patients considered disease-free following surgery received no further treatment.
Results: Ninety-four of 145 patients (65%) achieved a complete response (CR) or partial response (PR) with chemotherapy and 75 (52%) subsequently underwent complete resection of the primary tumor. Eighty-one patients are alive (73 without disease, eight with disease), 63 have died, and one is lost to follow-up. The 5-year overall survival (OS) rate is 55% and progression-free survival (PFS) rate 50%. Both OS and PFS correlated with response to chemotherapy, removal of primary tumor, HD therapy, and serum lactate dehydrogenase (LDH) levels. Infants (< 1 year), independent of primary tumor site, and children aged 1 to 15 years with a nonabdominal primary tumor, did better compared with children aged 1 to 15 years with an abdominal primary tumor (PFS, 72% and 64% v 30%; P < .001 and < .01, respectively). Outcome of this last group improved with the HD protocol (PFS, 40% v 23%; P = .01).
Conclusion: In children with unresectable neuroblastoma, risk categories can be defined by age and primary tumor site. HD chemotherapy should be investigated for the poor-risk category age 1 to 15 years with an abdominal primary tumor.