Diagnostics of pancreatic cancer
Clinical examinations performed to diagnose pancreatic cancer should focus on jaundice, epigastric tumors, an enlarged liver, ascites, an enlarged gallbladder (Courvoisier's sign), and enlarged lymph nodes in the neck (Virchov's gland). When symptoms, signs, and blood test results cause suspicion of pancreatic cancer, a swift and to-the-point work-up is of importance.
- A transabdominal ultrasound scan is usually the primary examination pancreatic cancer is considered. The examination is sensitive for detection of liver metastasis and ascites, and can show invasion of blood vessels. When ultrasound shows liver metastasis bioptically verified as adenocarcinoma, additional histological diagnostics of the primary tumor in the pancreas are not necessary.
- CT is sensitive for detection of the primary tumor and metastasis, and gives good information about the local extension of the tumor, especially the relation of the tumor to surrounding vessels. It is the standard for diagnosis and stage determination. The examination should be performed as a spiral CT with intravenous contrast and imaging of uptake in both early pancreatic parenchymal phase and portal venous phase, which is equivalent to late pancreatic parenchymal phase. This method is suitable for detection of invasion into vessels and/or vessel surrounding growth, as well as detection of variations in vessel anatomy. If the tumor is < 1 cm in diameter, the accuracy decreases significantly for the tumor both with US and CT.
- MRI of the pancreas with intravenous contrast can provide good morphological information about the extent of the tumor and invasion of blood vessels. MRCP (magnetic resonance cholangiopancreaticography) completed in the same session provides good visualization of the bile ducts and pancreatic duct. MRCP can be performed without contrast fluid and is non-invasive. Image examples: MRCP overview , MRCP and MRCP 3D . An MR examination does not necessarily provide better information of the tumor and vessel invasion than a CT scan. For practical purpose, CT often provides better visualization of the blood vessels than MRI. An X-ray of the thorax should be performed early in the work-up even though lung metastasis is relatively rare. In ambiguous cases, a CT of the thorax should be performed.
- Ampullary tumors growing into the duodenum can be visualized and biopsied using duodenoscopy. Pancreatic cancer in advanced cases, can grow into the stomach and may bediagnosed endoscopically.
- Endoscopic ultrasound (EUS) has shown to be a relatively good method to assess local invasion and allows for taking specimens for cytology. EUS provides high-resolution images in the parts of the pancreas with proximity to the duodenal wall.
- In resectable patients, obtaining tissue samples for cytological/histological examination should be avoided. Fine-needle aspiration cytology and/or core biopsy (tissue cylinder) are considered necessary to confirm the diagnosis before chemotherapy for patients who will not be operated.
- For an inoperable tumor, a biopsy is recommended to obtain definite diagnosis, especially to clarify whether the tumor is endocrine and not an adenocarcinoma.
- In patients with pancreatic cancer, ascites is a sign of an advanced, inoperable disease. A cytological examination of ascites may be of diagnostic value.
Chemical and molecular biological diagnostics, tumor markers
At present, there is no laboratory test of blood or urine, or a combination of tests, which is sufficiently sensitive and specific for this diagnosis.