Oral Presentation Advances in Neuroblastoma Research Congress 2016

Revised Children’s Oncology Group (COG) risk stratification incorporating the international neuroblastoma risk group staging system (#120)

Meredith S Irwin 1 , Arlene Naranjo 2 , Collin Van Ryn 2 , Susan L Cohn 3 , Wendy B London 4 , Julie Gastier-Foster 5 , Katherine K Matthay 6 , Edward F Attiyeh 7 , John M Maris 7 , Rochelle Bagatell 7 , Julie R Park 8 , MIchael D Hogarty 7
  1. Division of Hematology-Oncology, Hospital for Sick Children, Toronto, ON, Canada
  2. Statistics and Data Center, Children's Oncology Group, Gainesville, FL, United States
  3. University of Chicago, Chicago, IL, United States
  4. Boston Children's Hospital/Dana-Farber Harvard Cancer Center, Boston, MA, United States
  5. Nationwide Children's Hospital, Columbus, OH, United States
  6. University of California, San Francisco School of Medicine, San Francisco, CA, United States
  7. Childrens Hospital of Philadelphia, Philadelphia, PA, United States
  8. Seattle Children's Hospital/ University of Washington, Seattle, WA, United States

Background: The COG risk classification system previously used the International Neuroblastoma Staging System (INSS). Because the INRG staging system (INRGSS) has been adopted for clinical trials we integrated INRG stage with biological and clinical prognostic factors to map patient categories, evaluate outcomes and develop a revised risk classification system.

Methods: 4,255 newly diagnosed neuroblastoma patients were enrolled on COG Neuroblastoma Biology Study ANBL00B1 between 2006-2014. Staging per the INSS and INRG (using detection of Image Defined Risk Factor (IDRF)) was determined. Tumor biological and histologic features assessed in the centralized COG Neuroblastoma Reference lab included MYCN status, ploidy, INPC histology, and 1p and 11q LOH. Survival analyses were performed to identify independent prognostic factors and to calculate event-free and overall survival (EFS, OS) for combinations of variables used to determine risk group assignments according to both COG and INRG classification templates.

 Results: Using the COG risk classification 1,309 low-, 1007 intermediate- and 1,849 high-risk patients were identified. Concordance between INSS and INRG staging systems was higher for metastatic (4/M) as compared to loco-regional patients. 1,122 (67%) of loco-regional tumors had no IDRF (L1) and 545 (33%) had >1 IDRF (L2). Of the L1 patients 87% were INSS 1,2 while 61% of L2 patients were INSS 3. Subsets of L2 patients had sub-optimal outcomes (Table):

Discussion: The COG revised risk classification will designate L2 patients >18mo with MYCNA, unfavorable INPC histology, and/or segmental chromosome aberrations as high risk. Efforts to identify additional prognostic biomarkers may enable further refinement of risk groups.

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