Pediatric IFS with neonatal age (<3 months), low birth weight / failure to thrive (weight...

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

ID	`RF-IFS-FRAILTY-AGE`
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	Pediatric IFS with neonatal age (<3 months), low birth weight / failure to thrive (weight <-2SD for age), or hemodynamic instability — VAC cytotoxic protocols poorly tolerated in this very-young population; larotrectinib / entrectinib are the substantially safer alternative. This is the pediatric counterpart of adult frailty-age.
Clinical direction	de-escalate
Category	frailty-age

Trigger Logic

{
  "any_of": [
    {
      "comparator": "<",
      "finding": "age_months",
      "threshold": 3
    },
    {
      "comparator": "<",
      "finding": "weight_for_age_zscore",
      "threshold": -2
    },
    {
      "finding": "hemodynamic_instability",
      "value": true
    }
  ],
  "type": "composite_clinical"
}

Notes

IFS often presents at birth or in the first 6 months of life; very young infants tolerate cytotoxic chemotherapy poorly (myelosuppression, hepatic immaturity, cardiac sensitivity to anthracyclines). VAC protocol carries significant infectious mortality in <3 months. The emergence of TRK-inhibitors (larotrectinib pediatric label down to newborns; entrectinib down to 1 month) has transformed practice — these agents have ORR >90% and are the preferred 1L for fusion-positive IFS in this age group. This frailty flag pushes harder toward TRK- inhibitor monotherapy when fusion-positive (>90% of cases).

Used By

No reverse references found in the YAML corpus.