Chapter 73: Cancers of the Periampullary Region and Pancreas

INTRODUCTION

Periampullary adenocarcinomas are a set of neoplasms that arise near the ampulla of Vater. Although they are all adenocarcinomas, they arise from the different mucosal tissues of the pancreatic duct, bile duct, ampulla, and duodenum. They are often discussed together because they often share a common clinical presentation, they can be hard to distinguish on cross-sectional imaging, and when respectable, they are treated with pancreaticoduodenectomy.

Pancreatic adenocarcinoma is by far the most common of the 4 periampullary tumors. In fact, in 2016, it became the third most common cause of cancer death in the United States, and it is predicted that in the near future, it will become the second most common cause of cancer death.¹ Pancreatic adenocarcinoma accounts for a vast majority of the periampullary cancers, with the other 3 types being much less frequent. The 4 cancers have different resectability rates and long-term survival rates. Long-term survival is dependent on where cancer arose from, stage at diagnosis, degree of differentiation, and ability to completely resect cancer with negative margins.

In addition to these 4 types of adenocarcinomas, other less common tumors arise in the periampullary region including neuroendocrine tumors, acinar cell cancers, squamous cell carcinomas, gastrointestinal tumors, lymphoma, and metastases from other sites.

PERIAMPULLARY CANCER TYPES

Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma is the third leading cause of cancer death in the United States. In 2016, there will be an estimated 53,000 new cases diagnosed with 42,000 deaths from this disease.^1,2 The peak incidence of pancreatic cancer occurs in the seventh decade of life. African Americans have a higher risk of developing pancreatic ductal adenocarcinoma than do whites. There is a slightly higher incidence in men compared to women. The lifetime risk of developing pancreatic cancer is 1 in 65 and 1 in 67 in men and women, respectively, in the United States. Smoking is one of the strongest risk factors for the development of pancreatic cancer. Obesity has also been implicated, and other factors, such as diabetes and alcohol use, have also been implicated.

It is estimated that up to 10% of patients who develop pancreatic ductal adenocarcinoma have a familial predisposition. In the majority of these families, the genetic predisposition has not been identified. We do know, however, that mutations in the following genes can increase the risk of pancreatic cancer: BRCA2 (familial breast and ovarian cancer), PRSS1 (hereditary pancreatitis), p16 (familial atypical multiple mole and melanoma), and HNPCC (hereditary nonpolyposis colorectal cancer).³

Distal Bile Duct Cancer (Cholangiocarcinoma)

Distal cholangiocarcinoma is the second most common of the periampullary adenocarcinomas. Bile duct cancers or ­distal cholangiocarcinomas are typically grouped into 3 forms based on anatomic origin. Peripheral or proximal bile duct adenocarcinomas arise in the intrahepatic biliary tree. ­Perihilar cholangiocarcinomas arise near the ...