Carcinoma of the pancreas

Epidemiology:

• Fourth leading cause of death from cancer in the Western world
• In the UK ~ 5000 deaths per year
• Peak incidence is 50-70 yrs (although it occasionally occurs in those as young as 30 yrs)

Aetiology:

• Putative factors in exocrine pancreatic cancer:
• ‘Western’ lifestyle
• Cigarette smoking (perhaps due to nitrosamine inhalation)
• High-fat diet
• Working in chemical industries:
• beta-naphthylamines
• benzidine
• petroleum
• dry cleaning
• nuclear fuels
• coke and coal gas
• Men >> women (2 : 1)

Pathological features:

• 95% of tumours are adenocarcinomas, originating from the pancreatic ducts
• 70% of tumours occur in the pancreatic head
• Spread of the tumour is by four typical routes:
• Direct invasion
• Lymphatic
• Haematogenous
• Transcoelomic

Direct invasion:

Cancers arising from the pancreatic head invade and obstruct the lower end of the common bile duct to produce extra-hepatic obstructive jaundice

The development of obstruction causes the biliary tree to dilate

Of those pts with a tumour of the head of the pancreas, 15-20% have direct invasion of the duodenum, resulting in gastric outflow obstruction and vomiting

Lymphatic:

The most common nodes involved are the:

Pre-aortic coeliac nodes

Nodes of the porta-hepatis

Haematogenous:

The tumour drains into the portal vein and liver metastases are most common

Transcoelomic:

Spread across the peritoneal cavity resulting in:

peritoneal seedlings

ascites

Carcinoma of the pancreas

Clinical features:

Obstructive jaundice

Pruritus

Weight loss

Epigastric pain, which radiates through to the back and can sometimes be alleviated by sitting crouched forward

Recent dx of diabetes mellitus

Vomiting (if duodenal invasion has occurred – a sign of advanced disease)

Signs:

Virchow’s node (a palpable, hard, left supraclavicular lymph node)

Abdominal distension

Ascites

A palpable, enlarged, gallbladder

A palpable mass in the epigastrium which characteristically transmits aortic pulsation

Differential dx:

Choledocholithiasis

Malignant compression of the bile duct by metastases in portal lymph nodes

Drug-induced cholestatic jaundice

A carcinoma of the duodenum or papilla at the lower end of the common bile duct

Carcinoma of the bile duct

Mirizzi’s syndrome:

Cholecystitis and a gallstone in Hartmann’s pouch with local inflammation and oedema and sometimes erosion into the common hepatic duct

Sclerosing cholangitis

Investigations:

LFTs:

Show an obstructive pattern

Impaired glucose tolerance

Prolonged INR

Ultrasound:

Excludes gallstones in the gallbladder

May show a normal common bile duct

Dilated intra- and extra-hepatic biliary tree

May show a mass in the head of the pancreas

Possible liver metastases

Endoscopy:

Can demonstrate a malignant mass infiltrating the medial wall of the second part of the duodenum (from which a biopsy may be taken)

ERCP may indicate a malignant stricture of the common bile duct or pancreatic duct

Carcinoma of the pancreas

Percutaneous Transhepatic Cholangiography (PTC):

Done by direct puncture of the bile duct through the liver substance

Usually reserved for pts in whom ERCP has failed

CT:

Valuable in demonstrating the relationship of the tumour to the superior mesenteric vessels and portal vein

May show lymphatic and hepatic metastases

Specific serum tumour markers:

Elevated CEA (Carcinoembryonic antigen)

Elevated CA 19-9 (Carbohydrate antigen 19-9):

This is 90% specific for pancreatic cancer

Mx:

Resection of the primary lesion for cure (feasible on < 20%)

Alleviation of obstructive jaundice:

Stenting

Palliative surgical decompression (either cholecystojejunostomy or hepaticojejunostomy)

Pain control:

Narcotics

Coeliac plexus nerve block by alcohol injection

Rx of exocrine/endocrine failure:

Replacement therapy

Radiation and chemotherapeutic palliation:

Prognosis:

Very poor

Most pts are dead within two years of dx – more than 50% within 6 months

Even for those pts fortunate to present with a surgically resectable lesion, the 5yr survival after successful removal is < 20%