Prognostic value of clinicopathologic characteristics including neuroectodermal differentiation in osseous Ewing's sarcoma family of tumors in children

Aims and background: The aim of the present study was to determine the relationship between clinico-pathologic parameters, including neuroectodermal differentiation, and their impact on survival in a series of pediatric patients with osseous tumors of the Ewing's sarcoma family admitted to the Pediatric Department of the Istituto Nazionale Tumori of Milan. Methods: Seventy-three patients were enrolled. The variables analyzed were sex, age, site of primary tumor, serum lactate dehydrogenase (LDH) level at diagnosis, involvement of periosseous soft tissues by primary tumor, presence of metastatic disease, status of disease after the treatment plan, as well as the presence of mitoses, morphologic and immunocytochemical neural markers, and neuroendocrine markers in the primary tumor. Results: Neural and neuroendocrine markers were not significantly associated with any of the other parameters. In the univariate analysis, significant risk factors related to unfavorable outcome were elevated LDH, metastatic disease, lack of complete remission after treatment, presence of mitoses and of morphological neural markers; immunocytochemical neural and neuroendocrine markers lacked prognostic value. In the multivariate analysis, only LDH levels and the status of disease following the treatment were retained. Conclusions: LDH level at diagnosis might be a useful marker to identify different risk levels; neuroectodermal differentiation might have no clear-cut impact on the clinical management of osseous Ewing's sarcoma family of tumors.