Pancreatic Liver Cancer

What is Pancreas?

The pancreas is a 6-inch long organ located behind the stomach in the back of the abdomen. It is spongy and shaped somewhat like a fish, extended horizontally across the abdomen. The head of the pancreas is on the right side of the abdomen where the stomach is attached to the first part of the small intestine (the duodenum). The tail of the pancreas - its narrowest part - extends to the left side of the abdomen next to the spleen.

The pancreas contains exocrine and endocrine glands that create pancreatic juices, hormones, and insulin. Pancreatic juices, or enzymes, made by the exocrine glands are released into the intestines by way of a series of ducts in order to help digest fat, proteins, and carbohydrates. Over 95% of the pancreas is made up of exocrine glands and ducts. The endocrine cells are arranged in small clusters called islets of Langerhans, which release insulin and glucagon into the bloodstream. These two hormones manage levels of sugar in the blood. When they are not working properly, the result is often diabetes.

1. What is Pancreatic Cancer?

Cancers that build up within the pancreas fall into two major categories: (1) cancers of the endocrine pancreas (the part that makes insulin and other hormones) are called "islet cell" or "pancreatic neuroendocrine" cancers and (2) cancers of the exocrine pancreas (the part that makes enzymes). Islet cell cancers are uncommon and usually grow slowly compared to exocrine pancreatic cancers. Islet cell tumors often release hormones into the bloodstream and are further characterized by the hormones they produce (insulin, glucagon, gastrin, and other hormones). Cancers of the exocrine pancreas develop from the cells that line the system of ducts that carry enzymes to the small intestine and are commonly referred to as pancreatic adenocarcinomas. Adenocarcinoma of the pancreas comprises most of all pancreatic ductal cancers and is the subject of this review.

Bilirubin: A substance produced in the liver when the body breaks down hemoglobin, the molecule in red blood cells that carries oxygen.

Cells that line the ducts in the exocrine pancreas split more rapidly than the tissues that surround them. For reasons that we do not understand, these cells can make a mistake when they copy their DNA as they are reproducing to replace other cells. In this manner, an abnormal cell can be made. When an irregular ductal cell begins to divide in an unregulated way, a growth can form that is made up of abnormal looking and functioning cells. The abnormal changes that can be recognized under the microscope are called "dysplasia." Often, dysplastic cells can undergo added genetic mistakes over time and become even more abnormal. If these dysplastic cells invade through the walls of the duct from which they arise into the surrounding tissue, the dysplasia has become a malignant tumor (cancer).

What are pancreatic cancer causes and risk factors?

Most people who develop pancreatic cancer do so without any predisposing danger factors. Perhaps the biggest risk factor is increasing age. Being over the age of 60 puts an individual at greater risk. Rarely, there can be genetic syndromes that run in families that put individuals at higher risk such as BRCA-2 and, to a smaller extent, BRCA-1 gene mutations. Familial syndromes are curious but it is important to let your doctor know if anyone else in your family has been diagnosed with cancer. Moreover, certain actions or conditions are thought to slightly increase an individual's risk for developing pancreatic cancer. For example, African-Americans may be at greater risk as many individuals with close family members who have been previously diagnosed with the disease. Other behaviors or conditions that may put people at risk include tobacco use, obesity, a sedentary lifestyle, a history of diabetes, chronic pancreatic inflammation (pancreatitis), and a fatty (or Western) diet. Prior stomach surgery may moderately increase one's risk as can certain chronic infections such as hepatitis B and H. pylori (an infection of the stomach lining). Certain types of pancreatic cysts may put individuals at risk of developing pancreatic cancer. Despite these associated risks, no identifiable cause is found in most people who develop pancreatic cancer.

What is Pancreatic Cancer?- Video

What are the symptoms and signs of pancreatic cancer?

Because the pancreas lies deep in the belly in front of the spine, pancreatic cancer often grows silently for months before it is discovered. Early symptoms can be absent or quite subtle. More easily identifiable symptoms develop once the tumor grows large enough to press on other nearby structures such as nerves (which causes pain), the intestines (which affects appetite and causes nausea along with weight loss), or the bile ducts (which causes jaundice or a yellowing of the skin and can cause loss of appetite and itching). Symptoms in women rarely differ from those in men. Once the tumor sheds cancer cells into the blood and lymph systems and metastasizes, additional symptoms usually arise, depending on the location of the metastasis. Frequent sites of metastasis for pancreatic cancer include the liver, the lymph nodes, and the lining of the abdomen (called the peritoneum). Unfortunately, most pancreatic cancers are found after the cancer has grown beyond the pancreas or has metastasized to other places.

How is the diagnosis of pancreatic cancer made?

Most people with pancreatic cancer first present to their primary care doctor complaining of nonspecific symptoms. These complaints trigger an evaluation often including a physical examination (usually normal), blood tests, X-rays, and an ultrasound. If pancreatic cancer is present, the likelihood of an ultrasound revealing an abnormality in the pancreas is about 75%. If a problem is identified, frequently a computed tomography (CT) scan is performed as the next step in the evaluation. A pancreatic mass and the suspicion of pancreatic cancer is then raised and a biopsy is performed to yield a diagnosis.

Different strategies can be used to perform a biopsy of the suspected cancer. Often, a needle biopsy of the liver through the belly wall (percutaneous liver biopsy) will be used if it appears that there has been spread of the cancer to the liver. If the tumor remains localized to the pancreas, biopsy of the pancreas directly usually is performed with the aid of a CT. A direct biopsy also can be made via an endoscope put down the throat and into the intestines. A camera on the tip of the endoscope allows the endoscopist to advance the endoscope within the intestine. An ultrasound device at the tip of the endoscope locates the area of the pancreas to be biopsied, and a biopsy needle is passed through a working channel in the endoscope to obtain tissue from the suspected cancer. Ultimately, a tissue diagnosis is the only way to make the diagnosis with certainty, and the team of doctors works to obtain a tissue diagnosis in the easiest way possible.

In addition to radiologic tests, suspicion of a pancreatic cancer can arise from the elevation of a "tumor marker," a blood test which can be abnormally high in people with pancreatic cancer. The tumor marker most commonly associated with pancreatic cancer is called the "CA 19-9." It is often released into the bloodstream by pancreatic cancer cells and may be elevated in patients newly found to have the disease. Unfortunately, the CA 19-9 test is not specific for pancreatic cancer. Other cancers as well as some benign conditions can cause the CA 19-9 to be elevated. Sometimes the CA 19-9 will be at normal levels in the blood despite a confirmed diagnosis of pancreatic cancer, so the tumor marker is not perfect. It can be helpful, however, to follow during the course of illness since its rise and fall may help guide appropriate therapy.

How Can Pancreatic Cancer Be Prevented?

There are no established guidelines or recommendations for preventing pancreatic cancer, according to the American Cancer Society. However, it is advisable to quit smoking because cigarette use is thought to be a main factor in 20-30% of pancreatic cancers. In general, physicians recommend standard preventive measures such as keeping a healthy weight, exercising, and increasing consumption of fruits, vegetables, and whole grains while decreasing red meat intake. There is no evidence, however, that following these dietary guidelines will prevent or reduce pancreatic cancer.

Some studies suggest that certain vitamins can reduce the risk of pancreatic cancer. Vitamin D has been associated with reducing the risk of several types of cancer, including pancreatic cancer. B vitamins such as B12, B6, and folate that are consumed in food (not in pill or tablet form) have also been suggested to reduce pancreatic cancer risk.