Diagnosing Pancreatic Cancer: Advanced Scans, Biopsies, and Biomarkers

Last updated and reviewed on June 24, 2026.

Diagnosing pancreatic cancer accurately and completely is one of the most important steps in the entire care process, and it is also one of the most challenging. The pancreas sits deep in the abdomen, surrounded by other organs and major blood vessels, which makes it physically difficult to access. The symptoms of pancreatic cancer are often vague and overlap with common conditions like digestive disorders, back problems, or diabetes, which can delay the initial evaluation. And once a mass is found on imaging, determining its exact nature requires a carefully planned combination of further imaging, blood tests, and, in many cases, tissue sampling.

Getting this diagnosis right matters because the type of pancreatic tumor, its exact location, its relationship to nearby blood vessels, and whether it has spread all drive the treatment plan. Being evaluated at a high-volume pancreatic cancer center by a multidisciplinary team is strongly recommended because the complexity of these decisions benefits from specialized expertise.

What Tests Are Used to Diagnose Pancreatic Cancer?

• Medical History and Physical Examination: The process starts with a thorough medical history and physical exam. Your doctor will ask about your symptoms, how long they have been present, whether you have known risk factors (like smoking, diabetes, chronic pancreatitis, or a family history of pancreatic cancer), and whether you have had any recent changes in weight, appetite, or bowel habits. The physical exam may reveal jaundice, an enlarged liver, or tenderness in the upper abdomen, all of which can be clues that something is wrong in or near the pancreas.
• Blood Tests: A number of blood tests are useful in the evaluation of suspected pancreatic cancer.
• A complete metabolic panel and liver function tests can reveal whether the bile duct is obstructed (elevated bilirubin) and assess how well the liver is functioning. Elevations in liver enzymes like alkaline phosphatase and bilirubin are common when a tumor in the pancreatic head blocks the bile duct.
• CA 19-9 is a tumor marker that is elevated in many people with pancreatic cancer. It is the most commonly used blood test in pancreatic cancer management, but it is not a reliable diagnostic test on its own. CA 19-9 can be elevated in benign conditions like pancreatitis, bile duct infections, and liver disease, and it is undetectable in people with the Lewis-negative blood type even when cancer is present. Its greatest value is in monitoring how a patient responds to treatment and watching for signs of recurrence.
• CEA (carcinoembryonic antigen) is another tumor marker that is sometimes checked, though it is even less specific than CA 19-9 for pancreatic cancer.
• CT Scan of the Abdomen and Pelvis: A high-quality CT scan with intravenous contrast is usually the first and most important imaging test for suspected pancreatic cancer. A special protocol called a pancreatic protocol CT (also called multiphasic CT) uses carefully timed scans at different intervals after contrast injection to get the clearest possible view of the pancreas, the tumor, and its relationship to the major blood vessels nearby. This is critical for determining whether the tumor can be surgically removed.
  • The CT scan can show the size and location of the primary tumor, whether it has grown into or wrapped around nearby blood vessels (which determines whether surgery is technically possible), whether nearby lymph nodes are enlarged, and whether the cancer has spread to the liver or other organs. A high-quality pancreatic protocol CT at a specialized center is essential for accurate surgical planning.
• MRI and MRCP: MRI (magnetic resonance imaging) with MRCP (magnetic resonance cholangiopancreatography) provides a complementary view to CT that is particularly useful for characterizing cysts, evaluating the pancreatic duct and bile duct, and assessing the liver for metastases. MRCP creates detailed images of the bile duct and pancreatic duct without the need for an invasive procedure, which helps doctors understand the anatomy of the bile system before surgery or other interventions. MRI is also preferred over CT for patients with kidney problems who cannot receive CT contrast dye.
• Endoscopic Ultrasound (EUS): Endoscopic ultrasound involves passing a thin flexible tube with an ultrasound probe on the tip through the mouth and down into the stomach or small intestine, where it can be positioned right next to the pancreas. Because the probe is so close to the pancreas, EUS can detect very small lesions that CT or MRI might miss. It can also be used to guide a needle biopsy (called EUS-guided fine needle aspiration or fine needle biopsy) to obtain tissue from a suspicious mass for pathological analysis. EUS is particularly valuable when the diagnosis is uncertain or when tissue is needed before starting treatment.
• ERCP (Endoscopic Retrograde Cholangiopancreatography): ERCP uses an endoscope combined with X-ray to look at the bile duct and pancreatic duct from the inside. When a tumor is blocking the bile duct and causing jaundice, ERCP can be used to place a small tube called a stent inside the bile duct to relieve the obstruction and allow bile to flow again. This is a critical palliative procedure for many pancreatic cancer patients. During ERCP, brush samples or small biopsies can be taken from the bile duct, though this is less reliable for getting a tissue diagnosis than an EUS-guided biopsy.
• PET Scan: A PET scan uses a radioactive glucose tracer to find areas of high metabolic activity, where cancer cells often gather because they consume more sugar than normal cells. PET scans are sometimes used in pancreatic cancer staging to look for spread to lymph nodes or distant organs that might not be visible on CT. They are more commonly used in research settings or to evaluate equivocal findings on other imaging, rather than as a routine diagnostic step.
• Biopsy and Tissue Diagnosis: Obtaining a tissue sample is the only definitive way to confirm a diagnosis of pancreatic cancer. For patients who are going to have surgery, a biopsy is often not needed beforehand, because the surgical specimen itself provides the diagnosis. But for patients whose cancer appears to have spread or who are going to receive chemotherapy before surgery (called neoadjuvant therapy), a tissue biopsy is needed first.
  • The most common method is EUS-guided fine needle aspiration or fine needle biopsy, which is done through the endoscope as described above. For liver metastases, a CT-guided percutaneous needle biopsy is often used, where a needle is passed through the skin directly into a liver lesion using CT imaging as a guide.
• Molecular and Genomic Testing of Tumor Tissue: Once a tissue sample is obtained, molecular and genomic testing of the tumor has become an essential part of the diagnostic workup. Testing the tumor for specific gene mutations can identify actionable targets for treatment. The most important tests include:
  • • Testing for BRCA1 and BRCA2 mutations, because tumors with these mutations may respond to PARP inhibitor therapy (such as olaparib) after platinum-based chemotherapy.
    • Testing for mismatch repair deficiency (dMMR) or microsatellite instability (MSI-H), because tumors with these features may respond very well to immunotherapy (specifically pembrolizumab, which is FDA-approved for MSI-H tumors regardless of cancer type).
    • Testing for KRAS mutations, which are present in about 90 percent of PDAC cases, and are important for understanding the tumor biology.
    • Testing for NTRK gene fusions, which are rare but, when present, predict response to TRK inhibitor drugs. And germline (inherited) genetic testing for BRCA1, BRCA2, PALB2, ATM, and other cancer predisposition genes, which has implications for both treatment and for the patient's family members.

Sources:

1. American Cancer Society. Tests for Pancreatic Cancer. https://www.cancer.org/cancer/types/pancreatic-cancer/detection-diagnosis-staging/how-diagnosed.html
2. National Cancer Institute. Pancreatic Cancer Treatment (PDQ) Patient Version. https://www.cancer.gov/types/pancreatic/patient/pancreatic-treatment-pdq
3. National Comprehensive Cancer Network (NCCN). NCCN Guidelines: Pancreatic Adenocarcinoma. 2024. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1455
4. Pancreatic Cancer Action Network. Diagnosing Pancreatic Cancer. https://www.pancan.org/facing-pancreatic-cancer/learn/diagnosis/
5. Golan T, et al. Maintenance Olaparib for Germline BRCA-Mutated Metastatic Pancreatic Cancer. New England Journal of Medicine. 2019;381(4):317-327. https://www.nejm.org/doi/full/10.1056/NEJMoa1903387