High-risk neuroblastoma accounts for 4% of newly diagnosed pediatric malignancies, but for 9-10% of pediatric cancer mortality. To reduce the number of (late) recurrences and subsequently improve... Show moreHigh-risk neuroblastoma accounts for 4% of newly diagnosed pediatric malignancies, but for 9-10% of pediatric cancer mortality. To reduce the number of (late) recurrences and subsequently improve survival, anti-GD2 monoclonal antibody based immunotherapy has been added to the maintenance phase of treatment. The first randomized study (ANBL0032) was ground breaking, showing a 20% improved event free survival. Subsequently immunotherapy was included in all international high-risk treatment regimens. Randomization will never be repeated. In this article we present additional data from our retrospective cohort to corroborate the ANBL0032 study. Our cohort contains 84 Dutch high-risk neuroblastoma patients. They were treated with GPOH or POG induction, followed by immunotherapy according to original ANBL0032 protocol (immunotherapy group) or single-agent isotretinoin (historical control group). In the complete cohort, 5 year OS was 64 +/- 7% and 49 +/- 8% for the immunotherapy group and the control group, respectively (p = 0.16). Five year EFS was 57 +/- 7% and 41 +/- 8%, respectively (p = 0.16). In the subgroup of patients +/- 18 months, 5-yr OS was 63 +/- 8% and 39 +/- 9, respectively (p = 0.04) and EFS 54 +/- 8% and 29 +/- 8%, respectively (p = 0.05). Our five year data suggest a role for the immunotherapy in preventing late events, especially in patients >= 18 months old.Background: Anti-GD2 based immunotherapy has improved overall (OS) and event free survival (EFS) for high-risk neuroblastoma (HR-NBL) patients. Here, we evaluate the longterm efficacy of anti-GD2 immunotherapy in combination with isotretinoin, GM-CSF, and IL-2. Methods: Dutch HR-NBL patients treated with immunotherapy according to the COG-ANBL0032 protocol (n = 47) were included and compared to historical controls (n = 37) treated with singleagent isotretinoin maintenance therapy. Survival time was calculated from start of the maintenance therapy.Results: The study and control group were similar concerning baseline characteristics. In the complete cohort, 5 year OS was 64 +/- 7% and 49 +/- 8% for the immunotherapy group and the control group, respectively (p = 0.16). Five year EFS was 57 +/- 7% and 41 +/- 8%, respectively (p = 0.16). In the subgroup of patients >= 18 months, 5-yr OS was 63 +/- 8% and 39 +/- 9, respectively (p = 0.04) and EFS 54 +/- 8% and 29 +/- 8%, respectively (p = 0.05). Landmark analysis for EFS with landmark point at 6 months after start of maintenance suggests a larger effect on the prevention of late than early events.Conclusions: This study is the first to confirm the results of the COG-ANBL0032 study in a cohort treated with a different induction regimen. Anti-GD2 immunotherapy prevents late events, most significantly in patients older than 18 months of age at diagnosis. Show less
