Investigations
1st investigations to order
pancreatic protocol CT
Test
CT is used to diagnose and stage pancreatic cancer, and determine whether a tumour is resectable.[1][41]
All patients with suspected pancreatic cancer should undergo pancreas-specific CT.[1][68] This has been shown to achieve 97% diagnostic rates of pancreatic cancer with accurate prediction of resectability in 80% to 90% of patients.[18][44][45]
In the UK, urgent CT scan (or ultrasound if CT is not available) is recommended for patients ≥60 years with weight loss and any of the following: diarrhoea, back pain, abdominal pain, nausea, vomiting, constipation, or new-onset diabetes.[46] Patients aged 40 years and over with jaundice should be referred directly for an urgent hospital appointment.[46]
Result
may demonstrate a mass in the pancreas and the extent of local or distant spread
abdominal ultrasound
Test
Useful for initial work-up of abdominal pain or jaundice. There is a higher sensitivity for tumours in the head of the pancreas; sensitivity is lower for early disease, or for tumours in the body or tail of the pancreas.[18] May be difficult to visualise the pancreas due to overlying bowel gas or body habitus.[47] A normal ultrasound does not exclude pancreatic cancer, and where suspicion is present a pancreatic protocol CT is recommended.[1][46]
Result
pancreatic mass, dilated bile ducts, liver metastases
LFTs
Test
Demonstrates the degree of obstructive jaundice, but cannot distinguish between any cause of obstructive jaundice or liver metastases.
Result
bilirubin, alkaline phosphatase, and gamma glutamyl transpeptidase elevated in obstructive jaundice; aminotransferases (alanine aminotransferase) normal or slightly elevated
Investigations to consider
prothrombin time (PT)
Test
A derangement of vitamin K-dependent clotting factors will cause a prolonged PT. An FBC and clotting profile should be performed before any invasive diagnostic procedure.
Result
prolonged
FBC
Test
An FBC and clotting profile should be performed before any invasive diagnostic procedure.
Result
platelets decreased in disseminated intravascular coagulation; anaemia in gastrointestinal bleeding
cancer antigen (CA)19-9 biomarker
Test
Sensitivity of 70% to 90% and a specificity of 90%. False-positive results are often obtained in benign obstructive jaundice or chronic pancreatitis. Particularly useful as an aid in preoperative staging, in identifying recurrence in patients who have undergone resection, and in assessing the response to treatment in advanced disease.[18]
Result
elevated
positron emission tomography
Test
Often used in addition to CT scans if the diagnosis is still unclear.
PET/CT may be used as an adjunct to pancreatic protocol CT to assist detection of extrapancreatic metastases in high-risk patients. High-risk indicators are high symptom burden, borderline resectable disease, large primary tumour, large regional lymph nodes, and markedly elevated CA 19-9.[1]
PET/CT or PET/MRI may be considered to detect extrapancreatic metastases in patients with high-risk disease, but they should not be used as a substitute to contrast-enhanced CT.[1]
Result
may demonstrate a mass in the pancreas and the extent of local or distant spread
endoscopic retrograde cholangiopancreatography (ERCP)
Test
ERCP facilitates sample collection for cytology or histology and stent placement to palliate biliary obstruction when surgery is not elected or must be delayed.[18]
Result
ampullary tumour may be seen; all other pancreatic tumours are only detectable if there is pancreatic duct involvement
MRI
Test
Abdominal MRI is an alternative to CT.[1][47] High cost and limited availability mean it is most frequently used when CT findings are indeterminate or visibility of suspected pancreatic tumours is poor.[1] Abdominal MRI without contrast may be appropriate when contrast-enhanced CT is not possible.[41][47] MRI liver can be used to clarify ambiguous liver lesions, especially in the presence of biliary obstructions.[41]
Result
Can show suspected pancreatic tumours not visible on CT and characterise liver lesions not determined by CT
magnetic resonance cholangiopancreatography
endoscopic ultrasound
Test
Should be considered if there is no mass on CT but a clinical suspicion of pancreatic cancer. Highly sensitive in detecting small tumours (as small as 2-3 mm) and the involvement of major vascular structures (but less accurate in imaging the superior mesenteric artery), and in characterising pancreatic cystic lesions.[56]
Can be used for fine needle aspiration (FNA) of the pancreas and perivascular tissue cuffs; FNA of the latter can detect extravascular migratory metastases that are not visible on CT or MRI.[57][58][59] Risks of EUS-FNA include perforation, infection, iatrogenic pancreatitis, bleeding, bile peritonitis, and malignant seeding.[60]
Result
small tumours in the pancreas can be detected, as well as the involvement of certain veins: for example, portal vein
staging laparoscopy (with laparoscopic ultrasound)
Test
Can detect occult metastatic lesions in the liver and peritoneal cavity not identified by other imaging modalities. Particularly useful for lesions in the body or tail of the pancreas, or in patients with a higher risk of disseminated disease (borderline resectable, large primary tumour, high CA19-9).[61][62][63]
Result
can identify peritoneal, capsular, or serosal involvement, or small hepatic metastases not seen on CT
biopsy
Test
Diagnosis by histology is not required before surgical resection; a non-diagnostic biopsy should not delay appropriate surgical treatment when clinical suspicion of pancreatic cancer is high.[1] By contrast, in patients with advanced, unresectable disease selected for palliative therapy, biopsy confirmation is required.[65]
All patients should be referred to a centre with expertise in dealing with pancreatic diseases, without waiting for biopsy.
Guided biopsy or fine needle aspiration under endoscopic ultrasound, or pancreatic ductal brushings, or biopsies at ERCP, are preferable to a transperitoneal approach taken transcutaneously under ultrasound or CT guidance in patients with non-metastatic disease.[1] The two main concerns of transperitoneal techniques are the risk of a false-negative result and tumour cells spreading along the needle track or within the peritoneum.[66]
Biopsy proof of malignancy is not required before surgical resection, and a non-diagnostic biopsy should not delay resection if the clinical suspicion for pancreatic cancer is high.[1] Metastatic disease should ideally be confirmed by core biopsy from a metastatic site.[1]
Result
may confirm pancreatic ductal adenocarcinoma
Emerging tests
genomic testing
Test
Testing for actionable genomic mutations is recommended, if available, in selected patients with metastatic pancreatic cancer. Results are used to select the most suitable second-line treatment. Germline and tumour testing are recommended.[43]
Result
genomic alterations of interest include microsatellite instability/mismatch repair deficiency, BRCA mutations, and NRTK gene fusions
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