21 - Pancreatic and hepatobiliary cancer

Summary

Definitions

Pancreatic and hepatobiliary cancers are named after their respective anatomical organ sites. Pancreatic cancer does not refer to tumors arising from the endocrine pancreas, which are termed islet cell tumors. Biliary tract cancers include gallbladder cancers, and cholangiocarcinomas arising from the intrahepatic, or perihilar, or distal extrahepatic duct. Cancers arising at the bile duct bifurcation are called Klatskin's tumors. Cancers arising from the ampulla of Vater (the common point of entry of the bile and pancreatic ducts into the duodenum) and surrounding ampulla are termed ampullary cancers and periampullary cancers respectively (Figure 21.1).

Epidemiology and etiology

Pancreatic cancer

Pancreatic cancers afflict about 28 000 Americans per year and rank in fifth place in cancer mortality. The fact that the annual mortality rate of pancreatic cancer almost matches its annual incidence rate best illustrates its grave prognosis and lethality. Men, especially black men, are particularly at risk for the disease. The major risk factors for pancreatic cancer are smoking, with a relative risk of 4.0, and exposure to industrial carcinogens such as benzidine and naphthalamine. Poor dietary habits (high fat and low vegetable and fruit consumption), alcohol consumption, chronic pancreatitis, and diabetes are considered secondary risk factors. Patients with certain hereditary conditions, such as familial adenomatous polyposis (FAP) and Lynch syndrome II, BRCA1 and 2 carriers are also predisposed to pancreatic cancer as well as other types of cancers.

Biliary tract cancer

In the US, gallbladder cancer and cholangiocarcinoma account for 7000 and 5000 cases per year, respectively.