[Prognostic factors in neuroblastoma. Usefulness of DNA analysis using flow cytometry on paraffin-embedded material]

Nuclear DNA content was determined on paraffin blocks of 28 neuroblastic tumors retrieved from Surgical Pathology files. In 26 cases cytofluorimetric analysis for DNA content was satisfactory. 8 tumor were diploid, 12 were aneuploid and 6 tetraploid. All but one of the children with diploid neuroblastoma (NB) died after a survival ranging from 14 to 32 months. The only surviving child had a Stage I thoracic ganglioneuroblastoma (GNB) and was alive after 27 months. Conversely 11 of 12 patients with aneuploid tumors were alive with prolonged follow-up. Two children are alive after a period exceeding 146 months. The only exception in this group of aneuploid tumors was a child with Stage IV neuroblastoma of the adrenal gland with pleuro pulmonary metastasis who died after 6 months. In the group with tetraploid tumors 3 patients died (2 children with Stage III and IV died early while the third, with thoracic Stage II GNB, survived for 72 months). Two patients with tetraploid GNB Stage II and III are alive 65 and 72 months after diagnosis respectively. Another child with Stage IV adrenal NB is alive after 14 months but with metastatic spread to bones, bone marrow and lymph nodes. Cox analysis of the cases demonstrated ploidy as an independent prognostic factor. These results are in agreement with other molecular analysis linking near-ploidy of Neuroblastic tumors to poor prognosis. Ploidy, as detected by flow cytometry for nuclear DNA content, may represent an important prognostic factor in Neuroblastic tumors. The advantage of flow cytometry over other techniques of molecular analysis is represented by the simple methodology suitable for fixed and paraffin embedded tissue, even on retrieval material.