Impact of an objective scoring system on initiation of therapy in patients with International Neuroblastoma Risk Group Staging System (INRGSS) stage MS neuroblastoma: A report from the Children’s Oncology Group.

Abstract

10003 Background: A subset of children with INRGSS Stage MS neuroblastoma (NBL) may be observed without treatment, while others have rapidly evolving symptoms that can be life-threatening. ANBL1232 adapted a previously developed semi-quantitative objective scoring system (OSS) to assign a numeric value to symptoms and laboratory abnormalities. The goal was to standardize monitoring, therapy initiation, and treatment duration in this cohort. Methods: Patients with newly diagnosed Stage MS NBL were eligible for this prospective trial. An OSS score (OSSS) was assigned at enrollment; the total number was based on scoring in 5 systems: gastrointestinal (GI), respiratory, circulatory, renal, and hepatic. Within the 5 systems, individual clinical and laboratory parameters were scored as not present = 0, mild/moderate = 1 [Grade 2 CTCAEv4.0 adverse event (AE)] or severe = 2 (Grade ≥3 AE). The OSSS was the sum of highest score within each organ system (maximum score: 2 per system, 10 total). Asymptomatic MS patients with an OSSS < 2 who were either < 3 months (mo) of age without hepatomegaly or 3-18 mo of age with favorable biology tumors were eligible for observation without initial treatment. Observed patients underwent monthly physical examinations and laboratory assessments for the first 6 mo following diagnosis. Tumor imaging was performed every 3 mo for 1 year, then every 6-12 mo through 36 mo. An OSSS ≥2 or a protocol-defined increase in primary tumor size prompted initiation of therapy. Results: From July 2014 to February 2021, 89 eligible and evaluable patients with newly diagnosed stage MS NBL enrolled. Among these, 18 (20.2%; 5 male and 13 female) were eligible for observation. Observed patients were older at diagnosis (median age: 2.87 vs. 1.81 mo, p = 0.23) and more likely to have primary tumors without image-defined risk factors (62.5% vs. 30.0%, p = 0.0166) than those assigned to therapy up front. Nearly all observed patients (17/18) had abdominal/adrenal primaries. The initial OSSS was 0 in all observed patients. Median reported observation time was 36 mo (range: 1-36 mo); 13 patients completed all required monthly assessments for the first 6 mo. No patients in the observation cohort required initiation of therapy for an increase in OSSS. One patient with OSSS = 1 at mo 3 had complete GI symptom resolution by mo 5. Conclusions: An OSSS of 0 at diagnosis can aid in identifying a favorable group of patients with stage MS NBL who can be safely observed. No patients in the observation cohort developed evidence of organ dysfunction or OSSS > 1 despite frequent physical examination and comprehensive laboratory testing, suggesting that follow up may be safely liberalized in this population over time. Clinical and laboratory criteria implemented at diagnosis could be used to identify patients requiring prompt treatment. Clinical trial information: NCT02176967 .