Prognostic value of partial genetic instability in Neuroblastoma with ≤ 50% neuroblastic cell content.

Marta Piqueras (1) , Samuel Navarro (2) , Adela Cañete (3) , Victoria Castel (3) , Rosa Noguera (2)

1 Pathology
2 Pathology
3 Paediatric Oncology Unit

Aims. Better understanding of neuroblastoma genetics will improve with genome-wide techniques. However it is not adequated to perform these analyses in samples with less than 60% neuroblastic cell content. We evaluated the utility of FISH on tissue microarrays (TMA) in detecting partial genetic instability (PGI), focussing on samples with ≤ 50% neuroblastic cells. Methods and results. Alterations of 11q and 17q were detected by FISH on 369 neuroblastic samples included in TMA. Status of MYCN gene and 1p36 region was previously established by FISH diagnosis. Partial genetic instability (PGI) was defined as the ratio between segmental genetic alterations detected and number of genetic markers diagnosed in each tumor. 14.6% of primary tumors harbored 11q deletions, whereas 42.6% showed 17q gain. PGI was established in 260 primary tumors, 67 of them contained ≤ 50% neuroblasts. Outcomes were statistically worse for patients whose tumors presented high PGI (p<0.0001). Multivariate analysis revealed moderate and high PGI as prognostic factors. Conclusions. In our cohort, univariate and multivariate analysis confirmed the effect of PGI in patient outcome. PGI established by FISH on TMA is a useful method to identify high risk patients whose tumors have ≤ 50% neuroblastic cell content.

Mots clés: Medicine

Marta Piqueras, Samuel Navarro, Adela Cañete, Victoria Castel, Rosa Noguera. Prognostic value of partial genetic instability in Neuroblastoma with ≤ 50% neuroblastic cell content.. Histopathology, 2011, 59 (1), pp.22. ⟨10.1111/j.1365-2559.2011.03899.x⟩. ⟨hal-00651158⟩