[Effectiveness of high-dose polychemotherapy with autologous hemopoietic stem cell transplantation in the treatment for malignant tumors of the central nervous system in children and young adults].

A total of 40 patients (median age 6 years, range 1-28 years) with high-risk malignant brain tumors received a single (n = 35) or tandem (n = 5) high-dose chemotherapy (HDCT) with autologous hemopoietic stem cell transplantation (auto-HSCT). The 2-year OS and DFS are 52% and 47%, accordingly, with median follow-up of 24 (range 2-96) months. The patients without complete response at the time of auto-HSCT had worst prognosis with 53% DFS in patients with partial remission and 25% in patients with disease stabilization (p = 0.001). Patients with relapsed tumor had worse prognosis, than high-risk patients in the first remission with DFS 26% and 62%, accordingly (p=0.02). The relapse rate also correlated with patient's age (38% DFS in patients younger, than 4 years and 60% in older patients, p = 0.005) and tumor morphology (63% DFS in patients with medulloblastoma, 60% in patients with germ-cell tumors, 45% in other embryonal CNS tumors, p = 0.05). The 4th-grade transplant-related toxicity and mortality rates were observed in 13% and 18% of patients, accordingly. Therefore, HDCT with auto-HSCT in young patients with high-risk CNS tumors is characterized by acceptable toxicity and allows improving overall therapy results.

[Combined therapy for children and adolescents with Ewing tumors (a 25-year experience)].

A total of 115 children (median age 10.5 years, range 2-17) with Ewing sarcoma family tumors (ESFT) received therapy in N.N. Petrov Institute of Oncology pediatric department from April 1985 till August 2013. These patients were divided into two groups depending on treatment tactics used: patients treated according to modified T9 protocol (n = 64) and patients treated according to EICESS-92 or Euro-Ewing 99 regimens (n = 51). Twenty four patients from the second group with adverse prognostic factors received high-dose chemotherapy with autologous stem cell transplantation. All patients received surgical treatment and/or irradiation for primary tumor local control. Five-year overall and disease-free survival was 39% and 37,9% in the first group. In the second group these values were significantly higher; 55% and 39.5%, accordingly (p = 0.03 and 0.25). All patients from the first group with primary metastatic ESFT died of disease progression, while in the second group OS and DFS reached 45.8% and 28.9%, accordingly. There was a statistically significant correlation between local relapse rate and irradiation dose biological equivalent (in TDF units). The local relapse cumulative rate was minimal (12,6%) in patients receiving 80 TDF.