Reasoning GP · Algorithm · 1-page summary
Suspected cancer in children and young people
For: children (under 16) and young people (16–24) with unexplained or persistent symptoms in primary care. Not for: a critically unwell child (block 0 first) or known cancer (local acute oncology pathway). Age 16–24 → local teenage and young adult pathway: paediatric, TYA or adult services.
Core rule: "unexplained" or "persistent" means act at the NG12 time frame, not reassure. A normal test never overrides continuing clinical or parental concern.
0Stop — call 999 now — emergency admission, not an outpatient pathway
- Toxic or septic-looking, reduced consciousness, respiratory distress or airway compromise (possible mediastinal mass) → 999 / A&E
- New-onset seizure, signs of raised intracranial pressure, acute severe pain with haemodynamic or neurological compromise → 999 / A&E
- Petechiae with fever, toxic appearance, altered consciousness, shock or a rapidly progressive rash → manage as suspected sepsis 999. It may be meningococcal sepsis as well as leukaemia.
- Do not wait for an FBC or any other test before referring these children.
1Triage by NG12 action level — write it on the referral
| Level | Meaning |
|---|---|
| Immediate | Acute referral or admission within a few hours; 999 only if critically unwell |
| Very urgent | Test or appointment within 48 hours, with an explicit plan to review and act on the result |
| Suspected cancer pathway | Former "2-week wait": diagnosed or ruled out within 28 days |
| Other | Test, non-urgent referral or "consider referral", with safety-netting and review |
2Screen — immediate features first
- Unexplained petechiae or hepatosplenomegaly → Immediate specialist assessment for leukaemia; do not wait for an FBC.
- Reduced consciousness, focal deficit, rapidly progressive symptoms, persistent morning headache with vomiting; infant with bulging fontanelle or regression → Immediate emergency assessment.
- New squint with loss of the red reflex (one or both eyes) or neurological abnormality → Immediate ophthalmology (NG127).
- Nodes with new breathlessness (possible mediastinal mass) → Same-day assessment.
- Absent or abnormal fundal ("red") reflex, or white reflex in photos → consider Suspected cancer pathway ophthalmology.
- Unexplained bruising or petechiae → leukaemia and non-accidental injury; FBC and clotting fit both.
3Assess — every worrying child, fully
☐ Growth; head circumference if under 2 ☐ Temperature, full skin ☐ Nodes ☐ Abdomen, gently and once; BP if a mass ☐ Eyes: red reflex, squint, proptosis ☐ Neuro: gait, coordination, cranial nerves, fundi ☐ Bones and joints
Higher risk: Down syndrome, NF1, Li–Fraumeni, previous cancer treatment, family history of retinoblastoma, immunodeficiency.
Do not delay referral for primary-care imaging unless that is the local pathway.
4Classify — NG12 very urgent (48 h) actions
- Leukaemia — pallor, persistent fatigue, unexplained fever, unexplained persistent infections, generalised lymphadenopathy, persistent or unexplained bone pain, unexplained bruising or bleeding → very urgent FBC ≤48 h
- Brain/CNS — newly abnormal cerebellar or central neurology → consider referral ≤48 h. HeadSmart features (headache waking or on waking, vomiting on waking, visual, gait) → discuss or refer via local pathway.
- Neuroblastoma / Wilms' — palpable abdominal mass, unexplained enlarged organ or visible haematuria → consider referral ≤48 h
- Lymphoma — unexplained lymphadenopathy or splenomegaly → consider referral ≤48 h; weigh fever, night sweats, breathlessness, itch, weight loss.
- Sarcoma — unexplained bone pain or swelling → consider X-ray ≤48 h; enlarging lump → consider ultrasound ≤48 h; suggests sarcoma or uncertain with concern → consider referral ≤48 h
- Uncertain — repeat visits → diagnostic review: re-examine, second opinion.
5Act on results — name who checks them
- FBC with differential, film if leukaemia suspected; clotting if bruising; urine dip.
- Blasts, pancytopenia, severe or falling counts, abnormal film, or an unwell child → discuss with paediatrics/haematology Same-day
- Mild isolated abnormality, well child → interpret with the laboratory, context and trend.
- Named clinician checks the result within 48 h; tell the family how and when they will hear.
6Other action — planned review or advice
- Persistent parental concern → consider referral, even if a benign cause is likely; reassess and review past consultations.
- Symptoms not resolving, predisposition syndrome, or abnormal non-urgent results → planned review, paediatric advice or referral.
- Local paediatric pathway; speak clinician to clinician if concern is high.
7Never reassure by
- A normal FBC while concern persists; reassess and discuss, do not repeat FBCs indefinitely.
- A normal first X-ray when bone pain persists or progresses.
- "Growing pains" or minor trauma for night pain, limp or refusal to walk.
- The absence of fever, sweats or weight loss in a child with unexplained nodes.
- The first explanation for bruising: leukaemia and non-accidental injury both stay open.
- Calling the parent "anxious", or a young person presenting late or alone.
8Safety-net — say it, write it, document it
999 “Call 999 if spots or bruises come with a fever, or your child is drowsy, floppy or very unwell.” Same-day “If new spots or bruises appear, or they become more unwell, come straight back today, or call 111 out of hours.”
Explain the 48-hour plan as precautionary and who will contact them. Give written advice; investigate until symptoms are explained or resolved.
✓Safe to leave primary care only if — all five, documented
No block 0 or immediate block 2 feature
Full examination incl. skin, nodes, abdomen, eyes, neuro, growth
NG12 level chosen and written on the referral or test
Named clinician checks the result within 48 h
Parental concern recorded; safety-net given
Summary of the full Reasoning GP suspected cancer in children and young people algorithm, which holds the detail, HeadSmart features and evidence. Sources: NICE NG12 (updated April 2026), NG127; HeadSmart (RCPCH-endorsed); CCLG referral guidance. Clinical reference — follow local paediatric, teenage and young adult and acute oncology pathways.