How a Blood Test is Performed
Blood tests are a routine but vital part of a pancreatic cancer journey, providing critical information to guide your care. These tests help your medical team monitor your health, evaluate organ function, and assess the effectiveness of treatments like chemotherapy. In some cases, blood tests can also detect specific biomarkers or genetic information, which may guide more personalized treatment options.
Understanding what happens during a blood test can make the process feel less intimidating and give you a sense of control. Whether you are preparing for your first blood draw or have had multiple tests, knowing each step can provide reassurance and help you feel more at ease.
1. Preparation and Identification
Before starting the procedure, the healthcare provider will confirm the patient’s identity using identifiers like their name, date of birth, and a unique patient ID. This step ensures that the right patient is being treated and that the collected blood is labeled accurately.
2. Sanitization and tourniquets application
The healthcare provider will clean their hands and put on gloves to maintain a sterile environment, reducing the risk of infection. A tourniquet—a tight band—is applied around the upper arm to restrict blood flow temporarily, causing the veins to swell and become more prominent.
3. Vein selection and skin cleaning
The healthcare provider will visually inspect and palpate (feel) for a suitable vein, typically in the forearm. Once a vein is selected, the skin is cleaned with an antiseptic (like alcohol) to disinfect the area.
4. Needle insertion and blood collection
A sterile needle is inserted into the vein at the cleaned site. Blood is collected into one or more labeled tubes, depending on the number of tests required. The provider ensures a steady flow of blood while minimizing patient discomfort.
5. Tourniquet removal and post-draw care
After the required blood has been drawn, the tourniquet is released to restore normal blood flow. The needle is carefully withdrawn, and the site is immediately covered with gauze or cotton to stop bleeding. Pressure is applied for 1-2 minutes to prevent bruising.
6. Bandage application and sample labeling
A small bandage is applied over the puncture site to protect it from dirt and bacteria. The blood samples are immediately labeled with the patient’s details, including date and time of collection, ensuring they are sent to the lab with accurate identification.
What to Expect
Before the test:
• Inform about medications
• Follow fasting instructions if given
• Wear suitable clothing
During the test:
• Brief procedure (less than 5 minutes)
• Possible slight discomfort
After the test:
• Resume normal activities
• Keep bandage on for 15 minutes
• Avoid strenuous activities
Potential Side Effects
• Slight bruising (common)
• Lightheadedness (rare)
Results
Processing time varies. Your healthcare provider will discuss the results with you. Remember, blood tests are routine and essential. Don’t hesitate to ask questions if you have concerns.
Carbohydrate Antigen 19-9
Carbohydrate Antigen 19-9 (CA 19-9) is the most extensively studied and validated serum biomarker for pancreatic cancer.
CA 19-9
Key points:
• Normal range: 0-37 U/mL
• Sensitivity: 70-90%
• Specificity: 68-91%
Clinical utility
• Differential diagnosis between pancreatic cancer and chronic pancreatitis
• Assessing treatment response
• Follow-up of pancreatic cancer
• Prognostic indicator
Limitations
• Not suitable for screening asymptomatic individuals
• Can be elevated in non-cancerous conditions like obstructive jaundice and pancreatitis
• Not all pancreatic cancer patients have elevated CA19-9 levels.
• False positives can occur in benign conditions like pancreatitis or obstructive jaundice
Carcinoembryonic Antigen (CEA)
CEA is another tumour marker associated with pancreatic cancer, though less specific than CA 19-9.
Normal ranges
• Non-smokers: <2.5 ng/mL
• Smokers: <5.0 ng/mL
Clinical utility
• Can be used in combination with CA 19-9 to predict resectability of pancreatic cancer
• May be associated with poor treatment outcomes
Liver Function Tests
• Bilirubin: Elevated levels may indicate bile duct blockage
• Alkaline phosphatase: Can be increased due to bile duct obstruction
• ALT and AST: Liver enzymes that may be elevated in pancreatic cancer
Interpreting Results
It’s important to note that blood test results alone cannot definitively diagnose pancreatic cancer. Doctors consider these results alongside other diagnostic tools such as imaging tests and biopsies. Factors to consider when interpreting results include:
• Individual patient history
• Presence of other medical conditions
• Potential for false positives or negatives
Emerging Blood-based Diagnostics
What’s on the horizon for diagnostic tests which use your blood.
Current research and clinical trials are ongoing to develop more accurate blood tests for pancreatic cancer detection.
• Circulating Tumor Cells (CTCs): Detection of cancer cells in the bloodstream
• Cell-free DNA: Analysis of tumor DNA fragments in the blood
• Protein Panels: Combination of multiple protein markers for improved accuracy
Testing in Pancreatic Cancer
Explore comprehensive testing options for pancreatic cancer—from MRIs to blood tests—and learn how to interpret your results.
Explore TestingNote on Medical Information
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