Cancer Antigen 19-9
Code:10013
| Includes | CA 19-9 |
|---|
Analysis details
Methodology
- Electrochemiluminescence immunoassay (ECLIA)
Expected Turnaround Time
1 day
Special Instructions
- Refrain from smoking for at least 30 minutes before the blood draw.
- For serial monitoring, use the same assay methodology for each measurement and avoid changing platforms.
How to use
Cancer Antigen 19-9 testing (also known as Carbohydrate Antigen 19-9 or CA 19-9) is used in patients with pancreatic cancer whose pretreatment CA 19-9 is elevated to follow response to therapy and to monitor for disease relapse over time. In pancreatic cancer, serial values may approximate tumor burden and contribute to evaluation for distant metastatic spread. When interpreted alongside other tumor markers and the clinical evaluation, this gastrointestinal cancer antigen can aid in distinguishing pancreatic malignancy from nonmalignant conditions such as pancreatitis.
Limitations
CA 19-9 is a large glycoprotein produced by gastrointestinal epithelial cells. Concentrations are frequently increased in gastrointestinal malignancies, with the strongest association observed in pancreatic cancer. Elevations can also be seen with colorectal, hepatic, gastric, biliary, and ovarian tumors. Nonmalignant disorders can raise CA 19-9 as well, including hepatitis, cirrhosis, cholelithiasis, pancreatitis, and cystic fibrosis. Because sensitivity and specificity are limited, CA 19-9 alone is not recommended for primary cancer diagnosis.
| Reference interval |
| ||||
|---|---|---|---|---|---|
| Indications | Workup of suspected pancreatic adenocarcinoma, with symptoms such as epigastric pain, unintended weight loss, obstructive jaundice, or nausea, Longitudinal surveillance in pancreatic cancer when the baseline CA 19-9 concentration is elevated, Use with other tumor markers when malignancy is suspected in the biliary tract, gallbladder, liver, stomach, or colon |
Specimen Requirements
| Specimen | Serum |
|---|---|
| Container | Gold/Tiger Top (SST, Gel Separator) |
| Volume | 0.8 mL (min 0.4 mL) |
| Storage Instructions | Room temperature, Refrigerated, Frozen |