Pancreatic Cancer

What Is Pancreatic Cancer?

Most pancreatic cancers are exocrine cancers. Pancreatic neuroendocrine tumours (NETs), or islet cell tumours, are less common but tend to have a better outlook (prognosis).

If you have pancreatic cancer or are close to someone who does, knowing what to expect can help you cope. Here you can find out all about pancreatic cancer, including risk factors, symptoms.

Pancreatic cancer is a type of cancer that starts in the pancreas. (Cancer starts when cells in the body begin to grow out of control.

Pancreatic adenocarcinoma is the most common type of pancreatic cancer. Pancreatic neuroendocrine tumour’s (NETs) are a less common type and are discussed in

Where pancreatic cancer starts

The pancreas

The pancreas is an organ that sits behind the stomach. It's shaped a bit like a fish with a wide head, a tapering body, and a narrow, pointed tail. In adults it's about 6 inches (15 centimetres) long but less than 2 inches (5 centimetres) wide.

• The head of the pancreas is on the right side of the abdomen (belly), behind where the stomach meets the duodenum (the first part of the small intestine).

• The body of the pancreas is behind the stomach

• The tail of the pancreas is on the left side of the abdomen next to the spleen.

• The most common type of pancreatic cancer, adenocarcinoma of the pancreas, starts when exocrine cells in the pancreas start to grow out of control. Most of the pancreas is made up of exocrine cells which form the exocrine glands and ducts. The exocrine glands make pancreatic enzymes that are released into the intestines to help you digest foods (especially fats). The enzymes are released into tiny tubes called ducts which eventually empty into the pancreatic duct. The pancreatic duct merges with the common bile duct (the duct that carries bile from the liver), and empties into the duodenum (the first part of the small intestine) at the ampulla of Vater.

• Endocrine cells make up a smaller percentage of the cells in the pancreas. These cells make important hormones like insulin and glucagon (which help control blood sugar levels), and release them directly into the blood. Pancreatic neuroendocrine tumors start in the endocrine cells.

Types of pancreatic cancer

Exocrine cancers are by far the most common type of pancreas cancer. If you are told you have pancreatic cancer, it's most likely an exocrine pancreatic cancer.

Pancreatic adenocarcinoma

About 95% of cancers of the exocrine pancreas are adenocarcinomas. These cancers usually start in the ducts of the pancreas. Less often, they develop from the cells that make the pancreatic enzymes, in which case they are called acinar cell carcinomas.

Less common types of exocrine cancer

Other, less common exocrine cancers include adenosquamous carcinomas, squamous cell carcinomas, signet ring cell carcinomas, undifferentiated carcinomas, and undifferentiated carcinomas with giant cells.

Ampullary cancer (carcinoma of the ampulla of Vater)

This cancer starts in the ampulla of Vater, which is where the bile duct and pancreatic duct come together and empty into the small intestine. Ampullary cancers aren’t technically pancreatic cancers, but they are included here because they are treated much the same.

Ampullary cancers often block the bile duct while they're still small and have not spread far. This blockage causes bile to build up in the body, which leads to yellowing of the skin and eyes (jaundice). Because of this, these cancers are usually found earlier than most pancreatic cancers, and they usually have a better prognosis (outlook).

Risk Factors

A risk factor is anything that increases your chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, like smoking, can be changed. Others, like a person’s age or family history, can’t be changed. In some cases, there might be a factor that may decrease your risk of developing cancer or has an unclear effect. That is not considered a risk factor, but you may see them noted clearly on this page as well.

Having a risk factor, or even many, does not mean that you will get cancer. And some people who get cancer may have few or no known risk factors.

Here are some of the risk factors known to increase your risk for pancreatic cancer.

Risk factors you can change

Diabetes

Pancreatic cancer is more common in people with diabetes. The reason for this is not known. Most of the risk is found in people with type 2 diabetes. This type of diabetes is increasing in children and adolescents as obesity in these age groups also rises. Type 2 diabetes in adults is also often related to being overweight or obese. It’s not clear if people with type 1 (juvenile) diabetes have a higher risk.

Chronic pancreatitis

Chronic pancreatitis, a long-term inflammation of the pancreas, is linked with an increased risk of pancreatic cancer. Chronic pancreatitis is often seen with heavy alcohol use and smoking.

Workplace exposure to certain chemicals

Heavy exposure at work to certain chemicals used in the dry cleaning and metal working industries may raise a person’s risk of pancreatic cancer.

Age

The risk of developing pancreatic cancer goes up as people age. Almost all patients are older than 45. About two-thirds are at least 65 years old. The average age at the time of diagnosis is 70.

Sex

Men are slightly more likely to develop pancreatic cancer than women. This may be due, at least in part, to higher tobacco use in men, which raises pancreatic cancer risk .

Family history

Pancreatic cancer seems to run in some families. In some of these families, the high risk is due to an inherited syndrome . In other families, the gene causing the increased risk is not known. Although family history is a risk factor, most people who get pancreatic cancer do not have a family history of it.

Inherited genetic syndromes

Inherited gene changes (mutations) can be passed from parent to child. These gene changes may cause as many as 10% of pancreatic cancers. Sometimes these changes result in syndromes that include increased risks of other cancers (or other health problems). Examples of genetic syndromes that can cause pancreatic cancer include:

1. • Hereditary breast and ovarian cancer syndrome, caused by mutations in the BRCA1 or BRCA2 genes
2. • Familial atypical multiple mole melanoma (FAMMM) syndrome, caused by mutations in the p16/CDKN2A gene and associated with skin and eye melanomas
3. • Familial pancreatitis, usually caused by mutations in the PRSS1 gene
4. • Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC), most often caused by a defect in the MLH1 or MSH2 genes
5. • Peutz-Jeghers syndrome, caused by defects in the STK11 gene. This syndrome is also linked with polyps in the digestive tract and several other cancers.

Coffee

Some older studies have suggested that drinking coffee might increase the risk of pancreatic cancer, but more recent studies have not confirmed this.

Alcohol

Some studies have shown a link between heavy alcohol use and pancreatic cancer. Heavy alcohol use can also lead to conditions such as chronic pancreatitis, which is known to increase pancreatic cancer risk.

Infections

Some research suggests that infection of the stomach with the ulcer-causing bacteria Helicobacter pylori (H. pylori) or infection with Hepatitis B may increase the risk of getting pancreatic cancer.