Adenocarcinoma (Head of pancreas, periampullary, tail)

Pancreatic cancer is a type of cancer that begins as a growth of cells in the pancreas. The pancreas lies behind the lower part of the stomach. It makes enzymes that help digest food and hormones that help manage blood sugar.

The most common type of pancreatic cancer is pancreatic ductal adenocarcinoma. This type begins in the cells that line the ducts that carry digestive enzymes out of the pancreas.

Pancreatic cancer rarely is found at its early stages when the chance of curing it is greatest. This is because it often doesn't cause symptoms until after it has spread to other organs.

Your health care team considers the extent of your pancreatic cancer when creating your treatment plan. Treatment options may include surgery, chemotherapy, radiation therapy or a mix of these.

Symptoms

Pancreatic cancer often doesn't cause symptoms until the disease is advanced. When they happen, signs and symptoms of pancreatic cancer may include:

• Belly pain that spreads to the sides or back.
• Loss of appetite.
• Weight loss.
• Yellowing of the skin and the whites of the eyes, called jaundice.
• Light-colored or floating stools.
• Dark-colored urine.
• Itching.
• New diagnosis of diabetes or diabetes that's getting harder to control.
• Pain and swelling in an arm or leg, which might be caused by a blood clot.
• Tiredness or weakness.

Causes

It's not clear what causes pancreatic cancer. Doctors have found some factors that might raise the risk of this type of cancer. These include smoking and having a family history of pancreatic cancer.

Understanding the pancreas

The pancreas is about 6 inches (15 centimeters) long and looks something like a pear lying on its side. It releases hormones, including insulin. These hormones help the body process the sugar in the foods you eat. The pancreas also makes digestive juices to help the body digest food and take in nutrients.

How pancreatic cancer forms

Pancreatic cancer happens when cells in the pancreas develop changes in their DNA. A cell's DNA holds the instructions that tell a cell what to do. In healthy cells, the instructions tell the cells to grow and multiply at a set rate. The cells die at a set time. In cancer cells, the changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes there to be too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body.

Most pancreatic cancer begins in the cells that line the ducts of the pancreas. This type of cancer is called pancreatic ductal adenocarcinoma or pancreatic exocrine cancer. Less often, cancer can form in the hormone-producing cells or the neuroendocrine cells of the pancreas. These types of cancer are called pancreatic neuroendocrine tumors or pancreatic endocrine cancer.

Risk factors

Factors that might raise the risk of pancreatic cancer include:

• Smoking.
• Type 2 diabetes.
• Chronic inflammation of the pancreas, called pancreatitis.
• Family history of DNA changes that can increase cancer risk. These include changes in the BRCA2 gene, Lynch syndrome and familial atypical multiple mole melanoma (FAMMM) syndrome.
• Family history of pancreatic cancer.
• Obesity.
• Older age. Most people with pancreatic cancer are over 65.
• Drinking a lot of alcohol.

Complications

As pancreatic cancer progresses, it can cause complications such as:

• Weight loss. People with pancreatic cancer might lose weight as the cancer uses more of the body's energy. Nausea and vomiting caused by cancer treatments or a cancer pressing on the stomach might make it hard to eat. Sometimes the body has trouble getting nutrients from food because the pancreas isn't making enough digestive juices.

• Jaundice. Pancreatic cancer that blocks the liver's bile duct can cause jaundice. Signs include yellowing of the skin and the whites of the eyes. Jaundice can cause dark-colored urine and pale-colored stools. Jaundice often occurs without belly pain.

  If the bile duct is blocked, a plastic or metal tube called a stent can be put inside it. The stent helps hold the bile duct open. This is done using a procedure called endoscopic retrograde cholangiopancreatography, also called ERCP.

  During ERCP, a health care professional puts a long tube with a tiny camera, called an endoscope, down the throat. The tube goes through the stomach and into the upper part of the small intestine. The health professional puts a dye into the pancreatic ducts and bile ducts through a small tube that fits through the endoscope. The dye helps the ducts show up on imaging tests. The health professional uses those images to place a stent at the right spot in the duct to help hold it open.

• Pain. A growing tumor may press on nerves in your abdomen, causing pain that can become severe. Pain medications can help you feel more comfortable. Treatments, such as radiation and chemotherapy, might help slow tumor growth and provide some pain relief.

  When medicines aren't helping, a health care professional might suggest a celiac plexus block. This procedure uses a needle to put alcohol into the nerves that control pain in the belly. The alcohol stops the nerves from sending pain signals to the brain.

• Bowel blockage. Pancreatic cancer can grow into or press on the first part of the small intestine, called the duodenum. This can block the flow of digested food from the stomach into the intestines.

  A health care professional might suggest putting a tube called a stent in the small intestine to hold it open. Sometimes, it might help to have surgery to place a feeding tube. Or surgery can attach the stomach to a lower part of the intestines where the cancer isn't causing a blockage.