The rising incidence of pancreatic cancer

Cancer of the pancreas is a lethal disease with poor prognosis. The average lifetime risk of developing pancreatic carcinoma is one in 67, with an increasing number of cases diagnosed each year. The average five-year survival rate for pancreatic cancer is only five percent.

Surgical resection of pancreatic cancer remains the only chance for cure. In the last 20 years, continued progress has been made in the development of more effective perioperative management and refinement of surgical techniques.

Why is pancreatic cancer such a deadly disease?

The poor prognosis of pancreatic cancer is due to several factors. Early stage pancreatic cancer – when it is most treatable – often shows no symptoms. A small pancreatic tumour at the head of the pancreas may cause painless jaundice, but cancer at other locations in the pancreas routinely does not cause any symptoms until the tumour has become advanced or cancerous.

Up to 80 percent of patients with pancreatic cancer will present at a late stage of the disease. Their symptoms may include back pain, jaundice, weight loss, poor appetite, and steatorrhea.

Unfortunately, there is no effective screening method for detecting early pancreatic cancer at the asymptomatic stage. Carbohydrate Antigen 19-9 (CA 19-9) is a commonly used tumour marker for pancreatic cancer, however the main disadvantage of using CA 19-9 for screening is its high false positive rate. It is often elevated in other hepatobiliary conditions, such as jaundice due to non-cancerous causes, hepatitis, cirrhosis, and chronic pancreatitis.

In addition, the tumour biology of pancreatic cancer is such that it is one of the most intrinsically drug-resistant tumours. In advanced unresectable cases, chemotherapy alone offers a limited survival advantage of a few months (the average survival rate is five to nine months). There is also a high rate of relapse, even among early stage patients who undergo surgical resection and adjuvant chemotherapy.

Risk factors for pancreatic cancer

Smokers are twice as likely to develop pancreatic cancer compared to non-smokers. Obese people are at a 20 percent increased risk of pancreatic cancer. Other risk factors include age and family history. In some families, the risk of pancreatic cancer is due to inherited gene mutation syndromes, for example a mutation in the BRCA2 gene – the same gene that causes hereditary breast and ovarian cancer syndrome.

The best radiological modalities to investigate pancreatic cancer

The first line of imaging for patients with suspected pancreatic cancer is a multidetector computed tomography (CT) scan of the abdomen. This is usually performed with oral water contrast and intravenous iodinated contrast, scanning with thin (2mm-3mm) collimation during the pancreas phase.

Pancreatic cancer usually appears darker or of similar brightness when compared to the rest of the pancreas. Characteristics of the lesion on CT scan usually distinguish pancreatic cancer from other types of pancreatic masses.

Another option for cross-sectional scanning is magnetic resonance imaging (MRI) of the abdomen. MRI uses magnetic waves and therefore does not expose the patient to radiation.

It is, however, more expensive, takes longer to complete and may be limited by artefacts. CT and MRI have similar results in the detection and assessment of resectability for pancreatic carcinoma.

After detection of the pancreatic mass, further imaging of other parts of the body may be required to rule out metastatic disease and to stage the disease.

Obtaining a tissue biopsy for diagnosis

After appropriate imaging studies and staging, patients with resectable pancreatic cancer who are fit for major surgery do not necessarily need a histological confirmation of the diagnosis prior to surgery. A biopsy should be performed if other diagnoses which mimic pancreatic cancer are suspected, particularly in chronic or autoimmune pancreatitis.

Endoscopic ultrasound (EUS) – guided biopsy is the best method for obtaining a tissue diagnosis. An endoscopic ultrasound is a specialised side-viewing endoscope, which is combined with an ultrasound probe at the tip of the scope. It is advanced into the stomach and duodenum and used to visualise adjacent structures, particularly the pancreas and common bile duct.

A fine-needle aspiration (FNA) biopsy of the pancreatic mass may be performed under direct ultrasound guidance using the EUS. EUS-FNA has a high positive predictive value (99 percent) and a negative predictive value of 64 percent. Most surgeons will offer resection if imaging is suspicious for cancer even though FNA might be negative. EUS is also useful for evaluation of vascular invasion of the adjacent portal vein, superior mesenteric vein, superior mesenteric artery and celiac axis.

If EUS is not available, tissue diagnosis may be obtained using percutaneous FNA with image guidance.

Surgical options for resectable pancreatic cancer

For tumours in the head of the pancreas, the conventional pancreaticoduodenectomy (Whipple) procedure removes the pancreatic head, duodenum, proximal jejunum, gallbladder, common bile duct and partial gastrectomy. Modern modifications to this technique include the pylorus-preserving pancreaticoduodenectomy (PPPD), which preserves the gastric antrum and pylorus. This technique decreases the complications associated with a partial gastrectomy and has similar long-term survival compared to the Whipple procedure.

For tumours in the body and tail of the pancreas, surgical resection usually involves a distal pancreatectomy and splenectomy. This may be performed laparoscopically, though data assessing the oncological long-term outcome compared to the open technique is still limited.

Pancreatic cancer: the final word

Pancreatic cancer is a lethal cancer due to poor biology and late presentation. Surgical resection remains the best chance for cure and outcomes of resection have steadily improved due to refinement of techniques and perioperative management.

Dr Cheah Yee Lee is a general surgeon at the Asian American Liver Centre at Gleneagles Hospital Singapore. She is specialised in liver transplantation and surgery of the pancreas, the bile ducts and the liver. She completed her general surgery training from 2003 to 2008 at the General Surgery Residency Program at Brown University in Rhode Island, United States, where she was appointed Executive Chief Resident of General Surgery in 2008. She underwent advanced training in liver transplantation and hepatopancreatobiliary surgery at the Lahey Clinic in Massachusetts in the United States. She was also an Adjunct Assistant Professor at the National University Singapore, as well as a founding member of the Hepatopancreatobiliary Association of Singapore.

Gleneagles Hospital Singapore
6A Napier Road, Singapore 258500
Tel: (+65) 6735 5000
www.gleneagles.com.sg  

Asian American Liver Centre Pte Ltd (Gleneagles)
6A Napier Road #02-37, Singapore 258500
Tel: (+65) 6476 2088
www.aamg.co/liver