How is pancreatic cancer diagnosed?

Dr Daleen Geldenhuys explains the diagnostic process of exocrine pancreatic cancer.

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Pancreatic cancer is one of the most feared cancers with an extremely poor prognosis. The best survival chance would be to diagnose the disease early and yet again the average survival time is 36 to 42 months in early disease.

The pancreas is an important abdominal organ that lies in front of the vertebral column and behind the stomach. It looks like an upside-down smoking pipe and has several important structures around it. If the cancer grows too closely or involves the structures mentioned below, surgery becomes difficult or impossible.

There are major blood vessels associated with the same anatomical position. The splenic artery runs in close proximity to the pancreas and with cancers that are in tail of the pancreas, the spleen is sacrificed when the tumour is removed. The blood supply to the largest part of the small bowel (superior mesenteric artery) traverses the organ close to the head of the pancreas and makes resection difficult or impossible if the tumour grows circumferentially around these vessels.

The bile duct connects with the pancreatic duct in the head of the pancreas. This opens into the small bowel and delivers bile and digestive juices. This makes diagnosis difficult and surgical removal even more difficult.

Symptoms

There are many symptoms that a patient may present with, taking in mind that a few of these symptoms are shared with other cancers and even non-cancerous conditions.

The most common presenting symptoms are pain, jaundice, and non-intentional weight loss. Generalised weakness and severe abdominal pain often radiating to the back are common non-specific symptoms. 

Diagnostic tests

Blood tests may reveal abnormal liver function, like raised bilirubin and other enzymes in the liver, such as alkaline phosphatase (ALP) or gamma glutamyl transferase (GGT). The tumour marker we often use is Ca19-9 but it’s by no means diagnostic, just useful to see if the patient improves on treatment.

Imaging is an important tool in decision-making. An abdominal ultrasound can be useful to see a tumour in the pancreas but because of the proximity of the stomach, air may hinder the sonographer to accurately assess the whole organ and more extensive imaging is advised.

With a CT or PET-CT scan, it’s possible to identify a tumour in the pancreas. Occasionally it may be so small, it may be missed, but with enough clinical information from the referring doctor, the radiologist will find the tumour and will be able to see if there are suspicious lymph nodes in the area. CT scanning is useful to identify and stage the cancer by identifying the areas where it may have metastasised to.

The key diagnostic test: a biopsy

A tissue biopsy is necessary to accurately make the diagnosis and to plan therapy. The fine-needle aspiration or a bigger core needle biopsy (preferable to get better tissue) can be used to make a diagnosis.

The biopsy can be done in a radiology department as an outpatient, under local anaesthetic if the radiologist can safely puncture the skin with no large or small bowel loops in the way of the needle. Ultrasound- or CT-guided techniques are used to accurately place the needle.

If it’s not possible, an endoscopist (usually a medical or surgical gastroenterologist) can do a similar procedure during a gastroscopy, whilst you are sedated, puncturing the stomach wall under endoscopic ultrasound-guidance and placing the needle directly into the tumour. This is a very safe procedure.

If that isn’t possible because the tumour can’t be reached, a laparoscopic biopsy under general anaesthetic may be the only solution to attain tissue for evaluation.

Looking at the patient

The most important person in the diagnostic process is the patient. A family history of pancreas cancer and/or BRCA mutations (known germline, present from birth or somatic, diagnosed in another tumour) will confer a higher risk to develop the cancer than in the normal population. 

A significant smoking and/or drinking history adds to the risk of developing this cancer but in the absence, doesn’t nullify the risk to be diagnosed with pancreas cancer. Don’t think that vaping may be a safer option. 

Unexpected weight loss is most likely not attributed to a new fad diet. Don’t ignore significant tiredness, not everything is related to age.

If you’re constantly feeling unwell; have unexplained backpain that doesn’t relent by changing posture; have jaundice; or feeling nauseous all the time, seek medical attention and don’t ignore the symptoms. This is a fast-growing tumour and early diagnosis is key.

Header image by Freepik