Pancreatic cancer, also called pancreas cancer, occurs when cancer cells form in the tissues of the pancreas. The pancreas has two different functions:
- It makes enzymes that help digest food in the small intestine
- It makes hormones, such as insulin, that are secreted into the bloodstream Almost all pancreatic cancers start in the cells that make enzymes, and most pancreatic cancers are adenocarcinomas. The risk of pancreatic cancer increases with age, with most being diagnosed between 60 to 80 years old.
The most common malignant cancer of the pancreas, adenocarcinoma, involves the production of enzymes necessary for digestion. These cells make up the lining of the pancreatic duct (duct cells), through which pancreatic juice containing digestive enzymes flow. Cancer can also occur in the islet cells, which are clusters of cells that produce insulin, but tumors of this type are less common.
Adenocarcinoma is the most common cancer of the pancreas, accounting for 95 percent of cases. Adenocarcinoma involves cells that secrete digestive enzymes. Islet cell carcinoma involves cells that secrete a variety of hormones. Tumors can be functional and produce abnormally high amounts of hormones, or non-functional and not produce any hormones. Most islet cell tumors are malignant, but some are benign, such as insulin-producing islet cell tumors.
Isolated sarcomas and lymphomas can occur in the pancreas, but these are exceedingly rare.
Pseudopapillary neoplasms occur mostly in young women in their teens and twenties.
Pancreatic cancer often develops without early symptoms. The majority of symptoms arise because of the location of the pancreas and its relationship to organs of the digestive system.
Symptoms of pancreatic cancer include:
Jaundice occurs when bilirubin, a substance produced in the liver, builds up in the blood. Normally, bilirubin travels down the bile duct and passes through the pancreas just before emptying into the duodenum. However, if the bile duct becomes blocked, the level of bilirubin in blood rises, causing noticeably yellow skin and eyes.
Change of color in urine and stool: Urine may turn orange or the color of iced tea. Stool may turn yellow or reddish, or become grey or chalky-white. These are also symptoms of a blocked bile duct.
Pain occurs when a pancreatic tumor presses against or infiltrates nearby nerves. The pain may be a dull ache, a sensation of bloating or fullness or a burning type discomfort. Patients often find the pain difficult to describe.
Indigestion, lack of appetite, nausea, weight loss: These symptoms may occur when a pancreatic tumor presses against the stomach and small intestine. Nausea and weight loss may also occur if the release of pancreas enzymes is blocked for any reason and the body cannot absorb food completely.
Sudden-onset diabetes or a sudden change in blood-sugar control in diabetics: Diabetes may be an early symptom of pancreatic cancer as well as a risk factor.
Having one or more of the symptoms listed above does not necessarily mean you have pancreatic cancer. However, it is important to discuss any symptoms with your doctor, since they may indicate other health problems.
Diagnosing a tumor in the pancreas can be difficult. Symptoms are not always obvious, and usually develop gradually. Several medical tests are often required to establish the diagnosis and to determine whether it has spread beyond the pancreas.
Diagnostic tests for pancreatic cancer include:
Computerized tomography (CT): The CT scan is the primary test used to establish the stage of pancreatic cancer, which determines whether a tumor can be surgically removed. Using a special X-ray machine, this test gives detailed, three-dimensional pictures of the body and can help to determine if the tumor has spread.
Ultrasound is performed by placing a wand on the surface of the abdomen. The wand produces sound waves which form a picture of the inside of the body that is displayed on a computer screen. Ultrasound can help determine the size of the pancreas and possibly the presence of a pancreatic tumor. Endoscopic ultrasound (EUS) involves a special endoscope equipped with an ultrasound probe and a small needle at the end. The scope is placed inside the body through the mouth and esophagus and into the first portion of the small intestine. Surgical instruments, called biopsy forceps or brushes, may be inserted through the endoscope to collect a tissue sample for further testing (biopsy).
Endoscopic retrograde cholangiopancreatography (ERCP) is a procedure used to X-ray the ducts that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. An endoscope is inserted through the mouth, esophagus and stomach into the first part of the small intestine. A catheter (a smaller tube) is then inserted through the endoscope into the pancreatic ducts. A dye is injected through the catheter and an X-ray is taken. If the ducts are blocked by a tumor, a fine tube, or stent, may be inserted into the duct to unblock it. The stent may be left in place to keep the duct open.
Blood Tests: Currently, no single blood test can make the diagnosis of pancreatic cancer. Some blood tests, known as tumor markers, measure the levels of proteins produced by cancer cells. Known tumor markers for pancreatic cancer include carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA).
Although these tests may be useful when pancreatic cancer is suspected and to monitor the cancer, they are not an effective screening tool. Blood tests can also evaluate the function of the liver and other organs that may be affected by a pancreatic tumor.
Magnetic Resonance Imaging (MRI) uses a magnetic field and pulses of radio wave energy to make pictures of the inside of the body. The area of the body being studied is placed inside a special machine with a strong magnet. In some cases, a contrast material, or dye, may be used during the MRI to show pictures of organs or structures more clearly.
Positron Emission Tomography (PET) uses a special type of scanner and a form of sugar that contains a radioactive atom. This sugar is injected into a vein, and the scanner rotates around the patient's body and records the sugar as it moves through the body and collects in organs. Cancer cells show up brighter in the pictures because they absorb more sugar than normal cells.
Biopsy is the removal of a tissue sample so that it can be viewed under a microscope by a specially trained doctor to check for signs of cancer. There are several ways to do a biopsy for pancreatic cancer.
CT-guided Fine Needle Aspiration (FNA): The CT scan helps the doctor locate the tumor and guide a small needle through the skin and abdomen and into the pancreas to obtain a tissue sample.
Endoscopic Ultrasound FNA: A special endoscope equipped with an ultrasound probe and a small needle at the end is placed through the mouth into the esophagus and the first portion of the small intestine. The physician then performs an ultrasound and uses the needle to obtain a sample of any tissue that appears abnormal.
Laparoscopy: This procedure is done in the operating room under general anesthesia. A thin, lighted tube is guided through a very small (half inch) incision in the abdomen that enables the surgeon to directly visualize the pancreas and determine if the tumor has spread. Tissue samples can also be collected through the scope. Laparoscopy is not performed to diagnose pancreatic cancer, but it may be used to look for evidence that the cancer has spread to other organs, such as the intestines, liver, lymph nodes and stomach.
Staging is the process of describing the extent of the disease at the time of diagnosis. It is essential in choosing a treatment method and assessing prognosis (outcome). Cancer staging is based on the tumor's size, location and whether it has spread to other areas of the body.
Stage 0: Cancer is found only in the lining of the pancreas. Stage 0 is also called carcinoma in situ.
Stage I: Cancer has formed and is found in the pancreas only. Stage I is divided into stage IA and stage IB, based on the size of the tumor.
Stage IA: The tumor is two centimeters or smaller
Stage IB: The tumor is larger than two centimeters
Stage II: Cancer may have spread to nearby tissue and organs, and may have spread to lymph nodes near the pancreas. Stage II is divided into stage IIA and stage IIB, based on where the cancer has spread.
Stage IIA: Cancer has spread to nearby tissue and organs but has not spread to nearby lymph nodes
Stage IIB: Cancer has spread to nearby lymph nodes and may have spread to nearby tissue and organs
Stage III: Cancer has spread to the major blood vessels near the pancreas and may have spread to nearby lymph nodes.
Stage IV: Cancer may be of any size and has spread to distant organs, such as the liver, lung and peritoneal cavity. It may have also spread to organs and tissues near the pancreas or to lymph nodes.
Potentially curative surgery is used when diagnostic tests suggest that it is possible to remove the entire tumor. Most curative surgery is designed to treat cancers in the head of the pancreas, near the bile duct. Some of these cancers are found early enough because they block the bile duct and cause symptoms.
Only about 10 percent of pancreatic cancers appear to be contained entirely within the pancreas at the time of diagnosis. Attempts to remove the entire cancer may be successful in some patients. But even when there appears to be no spread beyond the pancreas at the time of surgery, cancer cells too few to detect may already have spread to other parts of the body.
There are three procedures used to remove tumors of the pancreas: Pancreaticoduodenectomy is the most commonly used surgery for attempted removal of a pancreatic tumor. Also known as the Whipple procedure, this operation removes:
- Head of the pancreas
- Body of the pancreas (in some patients)
- Part of the stomach
- Duodenum (first part of the small intestine)
- A small portion of the jejunum (second part of the small intestine)
- Lymph nodes near the pancreas
- Part of the common bile duct
This is a major operation that carries a relatively high risk of complications, even with experienced surgeons. About 30 percent to 50 percent of patients will suffer complications, including leakage from the various surgical connections, infections and bleeding. For the most successful outcome, patients must be treated by a specialized surgeon who has performed many of these operations at a cancer center with extensive experience in pancreatic surgery.
Distal Pancreatectomy removes only the tail of the pancreas, or the tail and a portion of the body of the pancreas. The spleen is usually removed as well. This operation is used more often with islet cell tumors.
Total Pancreatectomy, which removes the entire pancreas and the spleen, was once used for tumors in the body or head of the pancreas. However, when the entire pancreas is removed, patients are left without any islet cells, which produce insulin. This means patients will develop hard-to-manage diabetes and be totally dependent on injected insulin. There doesn't appear to be any treatment advantage to removing the whole pancreas.
Patients with potentially resectable (removable) pancreatic tumors may receive chemotherapy before or after surgery. Chemotherapy is often used to treat pancreas cancer that has metastasized. The kind of chemotherapy you receive and the length of your treatment will be determined by your doctor.
Often, patients may receive low doses of chemotherapy along with radiation to increase the effectiveness of the treatment. Patients with resectable pancreas cancer may receive radiation therapy before or after surgery.
New treatments are always being tested in clinical trials and some patients with cancer may want to consider participating in one of these research studies. These studies are meant to help improve current cancer treatments or obtain information on new treatments. Talk to your doctor about the clinical trials that may be right for you.