1. ¹Department of Experimental and Laboratory Medicine, Laboratory of Oncology, Gaslini Institute, Largo Gaslini, 5, Genoa 16147, Italy
2. ²Department of Experimental and Laboratory Medicine, Epidemiology and Biostatistics Section, Scientific Directorate, Gaslini Institute, Largo Gaslini, 5, Genoa 16147, Italy
3. ³Meyer Children's Hospital, Via Luca Giordano 13, Florence 50132, Italy
4. ⁴Service of Pathology, Gaslini Institute, Largo Gaslini, 5, Genoa 16147, Italy
5. ⁵Department of Hematology–Oncology, Gaslini Institute, Largo Gaslini, 5, Genoa 16147, Italy
6. ⁶Pediatric Oncology, Ospedale infantile Regina Margherita, Piazza Polonia 94, Torino 10126, Italy
7. ⁷Department of Pediatrics, II University of Naples, Via Sant'Andrea 4, Naples 80138, Italy

Correspondence: Dr MV Corrias, E-mail: mariavaleriacorrias@ospedale-gaslini.ge.it

⁸MV Corrias, S Parodi and R Haupt equally contributed as first authors.

⁹A Garaventa and L Faulkner equally contributed as last authors.

Received 23 August 2007; Revised 28 November 2007; Accepted 5 December 2007; Published online 8 January 2008.

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 1 10⁶ 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.