07 April 2020
Spotlight on the treatment of infantile fibrosarcoma in the era of NTRK inhibitors: international consensus and remaining controversies
This original work is on going. The study analyzed data for all published patients with infantile fibrosarcoma in the European pediatric Soft tissue sarcoma group (EpSSG) and the Cooperative Weichteilsarkomstudiengruppe (CWS) studies to better define the role of recent tyrosine kinase inhibitors (TKI) in this tumor. As the major effectiveness of NTRK inhibitors has come to significantly recently modify the overall therapeutic strategy of this tumor, we have presented for the first time an international consensual strategy based on EpSSG, CWS and Children’s Oncology Group (COG) experiences regarding the treatment of patients with IFS. We hope that this paper will help clinicians to better treat young children with infantile fibrosarcoma thanks to a better definition of the place of each treatment.
Overall, conventional conservative strategies prior to the era of targeted therapy, even in the case of extensive tumors, demonstrated efficacy in IFS, but are associated with acute and some chronic side effects. TRKI offers a novel, well-tolerated and often highly effective treatment for infants with NTRK gene fusion-positive IFS. Moreover, the oral solution of larotrectinib allows for easy administration in very young patients. The role of this effective drug upfront requires further study due to the absence of knowledge regarding its long-term effects, especially concerning neuro-developmental toxicity in very young children as TRK proteins are important in the early development of the brain. In cases of refractory tumors, of life-threatening situations or of metastatic tumors, TRKIs should be immediately considered. The final decision should also take the parental choice into consideration. However, until now, no specific medium-term toxicity has been reported in patients included in ongoing protocols. Taking into account all this information, the authors have proposed an algorithm to consider overall strategy in patients with IFS."
This work has been submitted in 2020 and is under review."
Overall, conventional conservative strategies prior to the era of targeted therapy, even in the case of extensive tumors, demonstrated efficacy in IFS, but are associated with acute and some chronic side effects. TRKI offers a novel, well-tolerated and often highly effective treatment for infants with NTRK gene fusion-positive IFS. Moreover, the oral solution of larotrectinib allows for easy administration in very young patients. The role of this effective drug upfront requires further study due to the absence of knowledge regarding its long-term effects, especially concerning neuro-developmental toxicity in very young children as TRK proteins are important in the early development of the brain. In cases of refractory tumors, of life-threatening situations or of metastatic tumors, TRKIs should be immediately considered. The final decision should also take the parental choice into consideration. However, until now, no specific medium-term toxicity has been reported in patients included in ongoing protocols. Taking into account all this information, the authors have proposed an algorithm to consider overall strategy in patients with IFS."
This work has been submitted in 2020 and is under review."
