The pancreas is a long, flat gland that lies in the abdomen behind the stomach. It produces enzymes that aid digestion and certain hormones that help maintain the proper level of blood sugar. The American Cancer Society estimates that in the U.S. in 2009, there will be 42,470 people diagnosed with pancreatic cancer and 35,420 deaths from pancreatic cancer, making it the nation's fourth leading cause of cancer death overall. Unlike other cancers, there is no screening test for pancreatic cancer. There are also no symptoms until the cancer has begun to spread, which accounts for the cancer's dismal survival rate.
Pancreas cancer remains one of the most lethal forms of human cancer, with a 5 year survival rate of only 3-5%. More than 80% of patients present with advanced disease at diagnosis and therefore are not candidates for potentially curative surgical resection. Gemcitabine, remains the standard approach for the treatment of locally advanced and metastatic pancreatic cancer since 1997 with a median survival of approximately 6 months.
Pancreatic cancer has been brought to the forefront by the diagnoses of several prominent figures, including the late actor Patrick Swayze, who died of pancreatic cancer in September 2009, Apple cofounder and CEO Steve Jobs, and U.S. Supreme Court Justice Ruth Bader Ginsburg. The lifetime risks of pancreatic cancer is about 1 in 76. Pancreatic cancer ranks as the fourth deadliest cancer.
Causes of Pancreatic Cancer
Although the exact cause of pancreatic cancer is not known, smoking is the main risk factor, with smokers 2-3 times more likely to have the disease than nonsmokers. Age is also related, with the disease usually striking after age 45. Diabetes is also linked to pancreatic cancer, with about 10-20% of those diagnosed with the cancer having diabetes. Other risks include chronic pancreatitis and cirrhosis of the liver. And family history of pancreatic cancer, high fat diet, obesity, and lack of exercise can also play a part.
Diagnosing Pancreatic Cancer
The challenge of this disease is finding it early. A doctor cannot see or feel a tumor during a routine exam. To help make the diagnosis (and determine the most appropriate treatment), imaging tests are performed (such as an ultrasound or CT scan) to view pictures of the abdomen and determine the extent of the problem. The green region shown in this colorized CT scan appears to be cancer in the pancreas and liver. The diagnosis comes from a biopsy — taking a tissue sample from the tumor — performed either with a needle through the skin or during an operation.
Stages of Pancreatic CancerStage is a term used in cancer treatment to describe the extent of spread. The stages of pancreatic cancer exist partly to guide treatment, but also to classify patients for clinical trials. The stages of pancreatic cancer are:
Stage 0: No spread. Pancreatic cancer is limited to a single layer of cells in the pancreas. The pancreatic cancer is not visible on imaging tests or even to the naked eye.
Stage I: Local growth. Pancreatic cancer is limited to the pancreas, but has grown to be less than 2 centimeters across (stage IA) or greater than 2 centimeters (stage IB).
Stage II: Local spread. Pancreatic cancer has grown outside the pancreas, and/or has spread to nearby lymph nodes.
Stage III: Wider spread. The tumor has expanded into nearby major blood vessels or nerves. As yet, pancreatic cancer can't be seen in other organs.
Stage IV: Confirmed spread. Pancreatic cancer is found in distant organs.
Recent advances into the molecular pathogenesis of pancreatic cancer have allowed researchers to better understand the involvement of multiple pathways and defined mutations associated with this tumor. This molecular heterogenicity is a major reason for failure of many targeted therapy. However, research over the last few decades have has led us to belief that pancreatic cancers show a progression model similar to that of colon cancer.
Chemotherapy uses drugs to destroy cancer cells by stopping them from growing or multiplying. Treatment may consist of just one drug or a combination of drugs. It may be given by mouth or by injection into a muscle or vein. The drugs enter the bloodstream and travel through the body, making chemotherapy a good choice for cancer that has spread. It is also useful after surgery to kill any cancer cells left behind.
Most if not all pancreatic cancer cllinical trials use gemcitabine -based chemotherapy in combination with a new study drug. It is likely that gemcitabine will continue to be a key drug in clinical trial design until another active agent is studied conclusively.
Pancreatic cancer clinical trials are necessary to determine whether new treatments developed in the laboratory are beneficial to people living with pancreatic cancer. The United States Food and Drug Administration (FDA) monitors most clinical trials to protect the participants and the general public. Ultimately, the FDA reviews and analyzes data from successful clinical trials to determine whether the experimental treatment should be approved for the treatment of a specific disease or disorder, such as pancreatic cancer.
Table Reference: Wong and Lemoine (2009). Nat. Rev. Gastroenterol. Hepatol. 6, 412.
Living with pancreatic cancer isn't easy; a support system is critical to help cope with the emotional and practical aspects of this aggressive disease. Many avenues for support exist within the local community and beyond, both for the patient and their family and friends. These organizations exist to help navigate the day-to-day treatment issues and the "big picture" worries about the future.