Detection of GD2-positive cells in bone marrow samples and survival of patients with localised neuroblastoma

Abstract

The impact of bone marrow (BM) GD2-positive cells on survival has been evaluated in 145 Italian children with localised neuroblastoma (NB) evaluated at diagnosis by anti-GD2 immunocytochemistry. Nineteen of these (13.1%) were found to be BM GD2-positive, with the number of positive cells ranging between 1 and 155 out of 1 x 10(6) total cells analysed. Seven/19 (38.8%) GD2-positive vs 12/126 (9.5%) GD2-negative patients relapsed. The 5-year event-free survival (EFS) and overall survival of the GD2-positive patients was significantly worse than that of the GD2-negative ones (62.2 vs 89.9%, P<0.001; and 74.9 vs 95.9%, P=0.005, respectively). GD2 positivity was not associated to other known risk factors, and in particular to Myc-N amplification and 1p deletion. Among Myc-N-negative patients, the EFS of those negative for both GD2 and 1p deletion was significantly better than in children positive for either one of these two markers (EFS=96.9 vs 66.0%, P<0.001). In conclusion, GD2 positivity may represent a prognostic marker for patients with non-metastatic NB without Myc-N amplification, and its combination with genetic alterations might help identifying patients that require a more careful follow-up.

Figure 1

Cytospin of BM aspirates fixed in acetone and immunologically stained with anti-GD2 antibody. (A, B) Rosettes of NB cells stained in red, from patients F/18 and F/8, respectively; (C) a single NB cell stained in red from patient M/73; (D) a completely negative aspirate. Magnification is × 40.

Figure 2

(A) Event-free survival of patients with localised NB stratified by BM GD2-IC status. (B) Overall survival of patients with localised NB stratified by GD2-IC status. (C) Event-free survival of patients with normal Myc-N status stratified by GD2-IC status. (D) Event-free survival of patients with normal Myc-N status stratified by GD2-IC and chromosome 1p status.