Cancer Antigen 19-9 (CA 19-9)
Sialylated Lewis(a) blood group antigen shed into circulation in high amounts by pancreatic, biliary, and gastrointestinal malignancies.
Standard vs. Optimal Reference RangesU/mL
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Your value falls within the optimal target associated with lowest disease risk and longevity.
<37.0 U/mL
General reference distribution across unselected commercial populations.
<20.0 U/mL
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Acts as a ligand for endothelial E-selectin, facilitating tumor cell extravasation and hematogenous metastasis.
Differential Diagnosis
Elevated Levels (CA 19-9 High)
- •Pancreatic ductal adenocarcinoma
- •Cholangiocarcinoma
- •Biliary tract obstruction / choledocholithiasis
- •Acute cholangitis
Low Levels (CA 19-9 Low)
- •Lewis-negative genotype (individuals lacking FUT3 cannot synthesize CA 19-9)
- •Healthy pancreaticobiliary baseline
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Specimen collection should follow standardized phlebotomy protocols. Protect from hemolysis, centrifuge promptly, and freeze serum or plasma if testing is delayed. Patient should be in a resting, fasting state where indicated.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker quantification for CA 19-9
- Targeted organ system imaging or functional dynamic testing related to sialylated lewis(a) pancreaticobiliary antigen
- Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Molecular Physiology of Cancer Antigen 19-9 - The New England Journal of Medicine (2021). PMID: 34090124
- [2]CA 19-9 Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35322901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Cancer Antigen 19-9 (CA 19-9) into overall healthspan optimization.