Rare Cancer Drug Response Reported in Young Child, New England Journal of Medicine Reveals

A medical journal has published correspondence describing how an infant with a rare soft tissue cancer responded to a targeted drug therapy linked to a specific genetic mutation.

What the Journal Published

The New England Journal of Medicine — one of the world’s most respected medical publications — posted details of a case involving infantile fibrosarcoma, a rare cancer that develops in soft tissue and most commonly affects children under the age of one.

At the same time, the correspondence, shared on the journal’s official X account, describes a response to crizotinib, a drug originally developed to treat certain lung cancers in adults. What makes this case stand out is the genetic detail at its heart.

The Gene Fusion Behind the Case

The child’s tumour carried what researchers describe as a *TFG::MET* gene fusion — a genetic abnormality in which two genes that should remain separate instead join together, driving abnormal cell growth.

Crizotinib works by blocking the activity of proteins produced by certain faulty genes, including MET. The suggestion in the correspondence is that targeting this specific fusion may have contributed to the child’s response to treatment. These are early findings from a single case report, and the journal presents them as correspondence rather than a full clinical trial.

It’s a small but potentially meaningful data point in a field where treatment options for very young children remain limited.

Why Infantile Fibrosarcoma Matters

Infantile fibrosarcoma is classified as a rare cancer. It accounts for a small fraction of childhood cancers overall, and most cases are diagnosed before a child’s first birthday. Surgery has traditionally been the main treatment, but tumours in certain locations can make that difficult or impossible.

Research into targeted therapies — drugs that attack specific genetic faults rather than blasting all fast-dividing cells — has opened new avenues for treating rare paediatric cancers. Cases like this one, where a known drug appears to work against an unusual genetic variant, help build the evidence base that oncologists rely on.

What Researchers Are Watching

The *TFG::MET* fusion is not the most commonly identified genetic driver in infantile fibrosarcoma. The more frequently seen fusion involves genes called *ETV6* and *NTRK3*, which respond to a different class of targeted drugs. This correspondence adds to growing interest in whether children whose tumours carry rarer fusions might benefit from drugs already approved for other conditions — a concept known as drug repurposing.

According to the New England Journal of Medicine’s editorial guidelines, correspondence of this kind is peer-reviewed before publication.

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Key Takeaways

• The New England Journal of Medicine has published a case report describing an infant with fibrosarcoma who responded to crizotinib, a targeted cancer drug
• The child’s tumour carried a *TFG::MET* gene fusion — a rarer genetic driver than those typically seen in this cancer type
• The findings are early and based on a single case, but add to research into repurposing existing drugs for rare paediatric cancers

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What This Means for Kent Residents

Families in Kent whose children are being treated for rare cancers are cared for through NHS services including those commissioned by NHS Kent and Medway Integrated Care Board, with specialist paediatric oncology care typically provided at regional centres. If you have concerns about a child’s health or an unusual diagnosis, your first step should always be to speak to your GP or call NHS 111. For families managing a childhood cancer diagnosis, the charity CLIC Sargent — now known as Young Lives vs Cancer — offers support and can be reached on 0300 330 0803. In a medical emergency, always call 999.