Impact of Extent of Surgical Resection on Survival in Patients With High-risk Neuroblastoma

Objective: The impact of extent of resection of the primary tumor on outcomes in patients with high-risk neuroblastoma (HRNB) remains uncertain. We evaluated this issue in patients with HRNB treated on a prospective trial of multimodality therapy. Summary of Background Data: Patients with HRNB enrolled on COG ANBL0532 who underwent surgical resection of their primary tumor during induction were included. Extent of resection was defined by the surgeon as complete excision (CE) if ≥90% of the tumor was resected, and incomplete excision (IE) if <90% was resected. Methods: Overall and event-free survival (OS, EFS) were estimated from time of surgery and compared between groups with a log-rank test. Cumulative incidence of local progression (CILP) was estimated using competing risks analysis and compared between groups with Gray test. Results: A total of 326 patients met inclusion criteria (CE=269, IE=57). Demographics were comparable between groups. CE was more likely in patients with adrenal tumors, MYCN -amplified tumors, and those without image-defined risk factors ( P <0.05). Patients with CE had improved 5-year EFS (50.3%±3.3% vs. 31.0%±6.4%; P =0.0016) and OS (61.8%±3.1% vs. 41.1%±6.9%; P =0.0094) and decreased 5-year CILP (12.8%±2.1% vs. 24.8%±5.8%; P =0.0306). When stratified by extent of resection and autologous stem-cell transplant type, patients with CE randomized to tandem transplant had the highest 5-year EFS, while patients with IE and single transplant had inferior outcomes (57.9±5.5% vs. 18.5±11.8%; P =0.0411). Among patients who received immunotherapy CE was associated with improved 5-year EFS. There was no difference in surgical complications between IE and CE. Conclusions: CE of the primary tumor was associated with significantly higher EFS, OS, and decreased CILP, with no increase in surgical complications. As part of a comprehensive, multimodal treatment strategy, complete primary tumor resection when feasible is a critical component of therapy.