RESUMO
Precision oncology requires tumor molecular profiling to identify actionable targets. Tumor biopsies are considered as the gold standard, but their indications are limited by the burden of procedures in children. Blood-derived liquid biopsy (LB) is a potential alternative that is not yet documented in real-world settings, especially in pediatric oncology. We performed a retrospective analysis of children and teenagers with a relapsing or refractory disease, upon whom LB was performed using the Foundation One® liquid CDx from 1 January 2020 to 31 December 2021 in a single center. Forty-five patients (27 boys) were included, with a median age of 9 years of age (range: 1.5-17 years old). Underlying malignancies were neuroblastoma (12 patients), bone sarcoma (12), soft tissue sarcoma (9), brain tumors (7), and miscellaneous tumors (5). Forty-three patients had metastatic disease. Six patients had more than one biopsy because of a failure in first LB. Median time to obtain results was 13 days. Overall, analysis was successful for 33/45 patients. Eight patients did not present any molecular abnormalities. Molecular alterations were identified in 25 samples with a mean of 2.1 alterations per sample. The most common alterations concerned TP53 (7 pts), EWS-FLI1 (5), ALK (3), MYC (3), and CREBBP (2). TMB was low in all cases. Six patients received treatment based on the results from LB analysis and all were treated off-trial. Three additional patients were included in early phase clinical trials. Mean duration of treatment was 85 days, with one patient with stable disease after eight months. Molecular profiling using Foundation One® Liquid CDx was feasible in pediatric patients with high-risk solid tumors and lead to identification of targetable mutations in a subset of patients.
RESUMO
BACKGROUND: Metronomic chemotherapy (MC) is defined as the frequent administration of chemotherapy at doses below the maximal tolerated dose and with no prolonged drug-free break. MC is gaining interest as an alternative strategy to fight resistant cancer. OBJECTIVE: to assess the safety of 4 drug MC regimen in paediatric patients with refractory or relapsing various tumour types. SETTING: From November 2008 to December 2010, in three academic paediatric oncology centers, 16 children (median age 12 years old; range 5.5-20) were included in this pilot study. This treatment was proposed to children with refractory disease for whom no further effective treatments were available. Most frequent diagnosis were medulloblastoma/cerebral PNET (5) osteosarcoma (5), and one case each of nephroblastoma, high grade glioma, Hodgkin lymphoma, rhabdomyosarcoma, neuroblastoma and kidney rhabdoid tumour. The MC regimen consisted in cycles of 56 days (8 weeks) with weekly vinblastine 3 mg/m2 (week 1-7), daily cyclophosphamide 30 mg/m2 (days 1-21), and twice weekly methotrexate 10 mg/m² (days 21-42), and daily celecoxib 100 mg to 400 mg twice daily (days 1-56) followed by a 2-weeks chemotherapy break. Adverse events were determined through laboratory analysis and investigator observations. RESULTS: One objective response was observed in a patient with Hodgkin lymphoma, and 4 patients experienced disease stabilization and continued their treatment for 3 cycles (24 weeks) or more. At last follow-up, 7 patients (43%) are alive including 1 still undergoing treatment. During the overall 36 cycles of treatments received by patients, 4 grade IV toxicities and 24 grade III toxicities were observed in 11 cycles in only 10 different patients. CONCLUSION: The metronomic regimen we report here was well tolerated and associated with disease stabilization. This regimen is currently being evaluated in a national multicenter phase II study.