The Efficacy of Camptothecin Variants on Incidental Relapsed/Refractory Malignancies of Childhood

In this study, we aimed to assessed the effect of camptothecin derivatives (irinotecan and topotecan) on median survival and disease-free survival and their effect on treatment responses in relapsed/refractory patients in real-life settings. In our study, we retrospectively evaluated patients under the age of 18 who were followed up in paediatric haematology clinics with the diagnosis of relapsed/refractory wilms tumour, neuroblastoma, osteosarcoma, ewing sarcoma and Medulloblasoma (MB) between 2017 and 2022. Patients who received irinotecan as salvage therapy were included in the study. A total of 71 patients from a single centre in Turkey were included in the study. All patients received at least 2 lines of treatment before relapse/refractoriness. Median overall survival times according to the response groups obtained with Campthotesin were statistically significant (p<0.001). Median overall survival times according to the permanent response groups were statistically significant (p<0.001). Median disease-free survival times according to the response groups obtained with campthotecin were statistically significant (p<0.001). Median disease-free survival times (months) according to the permanent response groups were statistically significant (p<0.001). According to the results of the multivariate Cox regression model, topotecan use (p=0.037) decreased mortality (p<0.001, -2 loglikelihood=338.33)> <0.001, -2 loglikelihood=338.33). The response obtained with PR (p=0.023) increased diseasefree survival, while topotecan use (p=0.034) decreased disease-free survival (p<0.001). Response and survival analyses obtained with the effect of camptothecin derivatives on topoisomerase indicate that appropriate treatment regimens containing camptothecin derivatives can be used for these patients.