Neuroblastoma with symptomatic spinal cord compression at diagnosis: treatment and results with 76 cases.

PURPOSE: To report on the treatment of patients with newly diagnosed neuroblastoma presenting with spinal cord compression (SCC). PATIENTS AND METHODS: Of 1,462 children with neuroblastoma registered between 1979 and 1998, 76 (5.2%) presented with signs/symptoms of SCC, including motor deficit in 75 patients (mild in 43, moderate in 22, severe [ie, paraplegia] in 10), pain in 47, sphincteric deficit in 30, and sensory loss in 11. Treatment of SCC consisted of radiotherapy in 11 patients, laminectomy in 32, and chemotherapy in 33. Laminectomy was more frequently performed in cases with favorable disease stages and in those with severe motor deficit, whereas chemotherapy was preferred in patients with advanced disease. RESULTS: Thirty-three patients achieved full neurologic recovery, 14 improved, 22 remained stable, and eight worsened, including three who become paraplegic. None of the 10 patients with grade 3 motor deficit, eight of whom were treated by laminectomy, recovered or improved. In the other 66 patients, the neurologic response to treatment was comparable for the three therapeutic modalities. All 11 patients treated by radiotherapy and 26 of 32 patients treated by laminectomy, but only two of 33 treated by chemotherapy, received additional therapy for SCC. Fifty-four of 76 patients are alive at time of the analysis, with follow-up of 4 to 209 months (median, 139 months). Twenty-six (44%) of 54 survivors have late sequelae, mainly scoliosis and sphincteric deficit. CONCLUSION: Radiotherapy, laminectomy, and chemotherapy showed comparable ability to relieve or improve SCC. However, patients treated with chemotherapy usually did not require additional therapy, whereas patients treated either with radiotherapy or laminectomy commonly did. No patient presenting with (or developing) severe motor deficit recovered or improved. Sequelae were documented in 44% of surviving patients.

c-kit is expressed in soft tissue sarcoma of neuroectodermic origin and its ligand prevents apoptosis of neoplastic cells.

During development, mice with mutations of stem cell factor (SCF) or its receptor c-kit exhibit defects in melanogenesis, as well as hematopoiesis and gonadogenesis. Consequently, accumulating evidence suggests that the c-kit/SCF system plays a crucial role in all of these processes and in tumors which derive from them. Especially in neuroblastoma (infant tumors of neuroectoderm crest derivation such as melanocytes) it would appear that an autocrine loop exists between c-kit and SCF, and that the functional block of the c-kit receptors with monoclonal antibodies (MoAbs) results in a significant decrease in cellular proliferation. We studied the expression and role of c-kit and SCF in cell lines of soft tissue sarcoma of neuroectodermic origin, such as Ewing's sarcoma (ES) and peripheral neuro-ectodermal tumors (PNET). Using flow cytometry with MoAb CD117 PE, c-kit expression was highlighted in all six of the cell lines examined. This receptor was specifically and functionally activated by SCF, as shown by the binding experiments and the intracellular phosphotyrosine and immunoprecipitation studies that were performed. Using reverse transcriptase polymerase chain reaction analysis, five of the six cellular lines expressed the mRNA of SCF. In the medium measured by using an enzyme- linked immunosorbent assay, low concentrations of SCF were found: only the TC32 cellular line produced significantly higher levels (32 pg) than control. In serum-free culture the addition of SCF reduced the percentage of apoptotic cells from 25% to 90% in five out of the six cellular lines. This observation was confirmed by (1) the functional block of c-kit with MoAb: after 7 days of culture more than 30% of the cells were apoptotic (range 31.5% to 100%) in five out of six cell lines and there was also a decrease in the percentage of cells in phase S, and (2) c-kit antisense oligonucleotides: in the cellular lines treated with oligonucleotides (in relation to the untreated lines) there was a notable reduction (P < .001) both in the absolute number of cells and the 3H-thymidine uptake. These results indicate that ES and PNET express c-kit and its ligand SCF and that SCF is capable of protecting the tumor cells against apoptosis. Furthermore, the reverse transcriptase-polymerase chain reaction performed on the biopsies revealed the presence of mRNA both of SCF and c-kit in practically all of the samples studied. Our in vitro data lead us to assume that SCF may also inhibit tumor cell apoptosis in vivo.

Stem cell factor suppresses apoptosis in neuroblastoma cell lines.

Stem cell factor (SCF) is a glycoprotein growth factor produced by marrow stromal cells that acts after binding to its specific surface receptor, which is the protein encoded by the protooncogene c-kit. SCF synergizes with specific lineage factors in promoting the proliferation of primitive hematopoietic progenitors, and has been administered to expand the pool of these progenitors in cancer patients treated with high-dose chemotherapy. SCF and its c-kit receptor are expressed by some tumor cells, including myeloid leukemia, breast carcinoma, small cell lung carcinoma, melanoma, gynecological tumors, and testicular germ cell tumors. Previous studies of SCF in neuroblastoma have produced conflicting conclusions. To explore the role of SCF in neuroblastoma, we studied five neuroblastoma lines (IMR-5, SK-N-SH, SK-N-BE, AF8, and SJ-N-KP) and the neuroepithelioma line CHP-100. All lines expressed mRNA for c-kit and c-kit protein at low intensity as measured by flow cytometry, and secreted SCF in medium culture as shown by ELISA. Exogenous SCF did not modify 3H thymidine uptake in the neuroblastoma and neuroepithelioma cell lines. After 6 days' culture in the presence of anti-c-kit, the number of viable neuroblastoma cells was significantly lower than the control, and terminal deoxynucleotidyl transferase assay showed a substantial increase of apoptotic cells: The percentage of positive cells was 1-3% in the control lines, whereas in the presence of anti c-kit it varied from 29% of SK-N-BE to 92% of CHP-100. After 9 days' culture in the presence of anti-c-kit, no viable cells were detectable. These data indicate that SCF is produced by some neuroblastoma cell lines via an autocrine loop to protect them from apoptosis.