When should I refer a patient for specialist evaluation based on their

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Refer patients for specialist evaluation based on biochemical results in the following scenarios:

If serum CA125 is 35 IU/ml or greater in women aged 18 and over, arrange an ultrasound scan of the abdomen and pelvis; if ultrasound suggests ovarian cancer, refer urgently via a suspected cancer pathway .
If serum protein electrophoresis or serum free light chain testing suggests myeloma, especially with persistent bone pain or unexplained fracture, refer via a suspected cancer pathway .
If serological tests for coeliac disease are positive (unambiguously positive IgA tTG alone, or weakly positive IgA tTG plus positive IgA EMA, or IgG antibodies in IgA deficiency), refer young people and adults to a gastrointestinal specialist for endoscopic biopsy confirmation .
If dementia is suspected after excluding reversible causes and cognitive decline is confirmed, refer to a specialist dementia diagnostic service for further assessment .

Additional biochemical-related referral triggers include:

Jaundice in people aged 40 and over should prompt referral for suspected pancreatic cancer .
Raised white cell count with unexplained non-visible haematuria in people aged 60 and over warrants referral for suspected bladder cancer .
Thrombocytosis in people aged 40 and over should prompt urgent chest X-ray; if accompanied by visible haematuria or unexplained vaginal discharge in women 55 and over, consider direct access ultrasound for endometrial cancer .

When should I refer a patient for specialist evaluation based on their biochemical results?