Infantile fibrosarcoma with NTRK fusion identified (ETV6-NTRK3 in >90%, LMNA-NTRK1 / TPM3...

Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.

ID	`RF-IFS-HIGH-RISK-BIOLOGY`
Type	Red flag
Status	reviewed 2026-04-27 \| pending_clinical_signoff
Diseases	`DIS-IFS`
Sources	`SRC-NCCN-PEDIATRIC-SARCOMA` `SRC-ONCOKB`

Red Flag Origin

Definition	Infantile fibrosarcoma with NTRK fusion identified (ETV6-NTRK3 in >90%, LMNA-NTRK1 / TPM3-NTRK1 in minor variants) — defines the entity and opens larotrectinib / entrectinib targeted therapy for unresectable or metastatic disease, sparing pediatric patient from VAC (vincristine / actinomycin / cyclophosphamide) cytotoxic adjuvant.
Clinical direction	intensify
Category	high-risk-biology

Trigger Logic

{
  "any_of": [
    {
      "finding": "BIO-NTRK-FUSION",
      "value": "positive"
    }
  ],
  "type": "biomarker"
}

Notes

ETV6-NTRK3 fusion is the molecular defining lesion of IFS; >90% of histologically classic IFS cases are positive. SCOUT (larotrectinib pediatric) and STARTRK-NG (entrectinib) showed ORR 80-90% in NTRK- fusion pediatric sarcomas including IFS — durable responses, manageable toxicity (weight gain, transient transaminitis). NCCN tumor-agnostic category 1 for NTRK-fusion-positive solid tumors. NTRK-inhibitor 1L is now standard of care displacing surgery-then-cytotoxic-VAC for unresectable IFS. Source gap: SRC-NCCN-PEDIATRIC-SARCOMA cites pediatric sarcoma working group; tumor-agnostic FDA approval underpins regimen.

Used By

No reverse references found in the YAML corpus.