Nomogram for the determination of primary-resistant forms of germ cell tumors in children

Introduction. Stratification of patients with germ cell tumors is primary carried out depends on stage and previous operation, at the same time is not considered the tumor markers decline.The aim of the study was the nomogram creation for diagnostics of the prolonged alfa-fetoprotein (AFP) half-life (HL) in patients with germ cell tumors in order to identify of a patients cohort with chemoresistant malignancy and to find treatment modification with transition to the escalated and intensified modality therapy.Materials and methods. Seventy-two patients less than 18 years old with extracranial germ cell tumors were treated in N.N. Petron National Medical Research Centre of Oncology between 1996 and 2017, among them with increased AFP were 46 (63.9 %) children. AFP half-life periods were calculated.Results. AFP half-life varied from 3 to 138 days (the average value was 15.6 days). A cut-off point at 6 days was found. An unfavourable decline in AFP was predictive overall survival (OS). OS rates were 85.2 ± 7.9 % and 50.1 ± 12 % in patients with HL £ 6 days, and with > 6 days, respectively (p = 0.01873). Nomogram for diagnostics of the prolonged AFP HL in patients with childhood extracranial germ cell tumors was built. Sensitivity, specificity and diagnostic accuracy of nomogram were 92.9 %, 63.6 % and 72.3 %, respectively. False negative result was in one case (2.1 %).Conclusions. Secondary stratification of patients has to be carried out after induction treatment with use of the principles of “response-based” of therapy. The nomogram allowing revealing the cohort of patients with prolongation of the period of AFP HL demanding early escalation and an intensification of medical programs helps with such cases for diagnostics of reduction in the rate of disintegration of AFP.