It is hard to say anything good about cancer, but actually, some cancers are better than others. For example, we often have good things to say about colon cancer which can largely be prevented by regular screening exams. Every colon polyp discovered and removed is a potential colon cancer prevented. The same is true for cervical cancer where Pap smears have saved thousands of lives. It is much more rewarding to prevent a cancer than to find one.
Unfortunately, the same can not be said for pancreatic cancer. At present, there are no early screening techniques for this disease. By the time pancreatic cancer is diagnosed, it is usually too late for a promising outcome. In fact, pancreatic cancer has the lowest 5 year survival of any cancer.
Where is the pancreas?
The pancreas is an elongated gland located deep in the abdomen. It is surrounded by the stomach, intestines, and other organs. The pancreas is about 6 inches long and is shaped like a long, flattened pear - wide at one end and narrow at the other. The wide part of the pancreas is called the head, the narrow end is the tail, and the middle section is called the body of the pancreas. The majority of pancreatic cancer, 80%, occurs within the head of the pancreas gland.
What does the pancreas do?
The pancreas has two main functions. One is to produce hormones such as insulin, which regulates the blood sugar. The other is to secrete digestive enzymes into the small intestine to help digest fats and proteins in our diet. There are a series of ducts inside the pancreas that collect these enzymes. Like branches of a tree, these small ducts come together to form the main pancreatic duct which carries the digestive enzymes to the small intestine.
What is pancreatic cancer?
The organs of the human body are made of billions of small cells. There is a natural balance. When old cells die, they are replaced at the same rate by newly formed younger cells. Cancer occurs when cells multiply too rapidly and begin to invade and destroy the tissue around them. There are many kinds of cancer. Pancreatic cancer occurs when a malignant tumor forms within the pancreas - usually starting in the lining of the pancreatic duct. Pancreatic cancer is not an uncommon illness. For unknown reasons, the number of cases has increased three-fold in the last 40 years. We are not sure whether its incidence is truly increasing or if it is just better diagnosed now. In either case, most people are unaware that pancreatic cancer is now the number 4 leading cancer killer in this country, accounting for over 29,000 deaths each year.
Who gets pancreatic cancer?
Anyone can develop this disease, but certain risk factors have been identified.
Family history. People in affected families have about a three-fold higher risk compared to the general population. Five to ten percent of patients with pancreatic cancer report a family history of the disease.
Cigarette smoking. Smoking is believed to cause up to a third of pancreatic cancers. People who smoke for twenty years or more have double the risk of those who have never smoked, and recent evidence indicates that this risk may be even higher when certain genetic factors are present.
Long-standing diabetes. There is a two-fold increased risk of pancreatic cancer among people who were diagnosed with diabetes mellitus at least five years before their diagnosis of pancreatic cancer.
Chronic pancreatitis. Pancreatic cancer risk among individuals with pancreatitis (inflamed pancreas) is 20 times higher than those without chronic pancreatitis. This is even more pronounced in cases of hereditary pancreatitis.
Diet and nutrition. Subjects who ingest a diet high in fat and cholesterol are at higher risk for development of pancreatic cancer than those who eat a low-fat low-cholesterol diet.
What are the symptoms of pancreatic cancer?
The diagnosis of pancreatic cancer is almost always delayed due to lack of early warning signs and symptoms. Pain is usually the complaint that motivates patients to seek a physician's care, but by this time the cancer has already reached an advanced stage. Even then, pancreatic cancer may be diagnosed as another illness because of the nonspecific nature of the symptoms.
Common symptoms include:
Unexplained weight loss
Nonspecific digestive or bowel symptoms such as diarrhea, bloating or gas, nausea, vomiting or loss of appetite
Occurrence of progressive painless jaundice, a yellowish discoloration of the skin and whites of the eyes with dark-colored urine
Sudden onset of new diabetes
A complete medical history and physical exam is usually done. Routine blood work and CA 19-9 tumor markers are often obtained. In most cases, special imaging studies are also performed. These may include:
Although pancreatic cancer starts in one duct, it quickly spreads throughout the pancreas. Eventually the cancer breaks free of the pancreas and invades local lymph nodes and other organs. It is disappointing that pancreatic cancer metastasizes early. Many primary tumors that are less than 1-2 cm in size have already spread beyond the pancreas when discovered. The lungs and liver often become breeding grounds for the cancer to grow.
Staging refers to finding out how far advanced the cancer has become. In many other cancers, accurate staging is an important part of treatment. However, in pancreatic cancer the importance of staging beyond that of "resectable" and "unresectable" is uncertain since state-of-the-art treatment has demonstrated little impact on survival.
Treatment
Three types of treatment exist for pancreatic cancer: surgery, radiation therapy, and chemotherapy - but all generally have little influence on the outcome. Surgery involves removal of the head of the pancreas (Whipple procedure), or the total removal of the pancreas (total pancreatectomy). These surgical resections are performed only when the potential for a cure exists. Pancreatic cancer is a deadly cancer. At the time of diagnosis 90% of tumors have already spread beyond the confines of the pancreas and cannot be resected. Bypasses are done for areas which are obstructed by tumor growth such as the bile ducts or duodenum.
Radiation Therapy is used to kill cancer cells and shrink tumors by use of x-rays or internal radiation therapy with radioisotopes. It is also used post operatively as a supplement to chemotherapy, but the decrease in mortality is not conclusive and gastrointestinal bleeding and distress are adverse effects.
Chemotherapy uses drugs to kill the cancer cells and is given intravenously, by injection or by mouth. This method can kill the cells inside and outside the pancreas. Side effects include low white blood cell counts, nausea, fatigue, hair loss, and diarrhea.
All treatments, even with early detection, have yielded poor results. So far, there is no drug that is greatly effective. Radiation and Chemotherpapy only improve survival by a couple of months. Most patients die within six months of diagnosis even with treatment. For this reason, treatment is often not directed towards a cure, but rather to temporarily improve symptoms. This is called palliation.
Pain Control
Pain control is an important part of treatment. It may not affect overall survival, but does improve the quality of life. Early treatment of pain is almost always more effective than waiting until the pain is severe or unbearable. Today, there is no reason that cancer pain should go untreated or ignored. Pain control techniques include nerve blocks, and various drugs that can be taken by mouth or injection.
Stress Palliative efforts may also be directed to dealing with the anxiety and depression associated with the diagnosis and treatment of pancreatic cancer.
Nutrition
A person with pancreatic cancer may no longer be able to produce enough pancreatic juices and hormones - especially if surgery is performed. This may lead to a malabsorption of nutrients and cause malnutrition. Prescription pancreatic enzyme supplements can help reduce this problem. It is also important to monitor and control blood sugar which is often elevated.
Prognosis
Pancreatic cancer disease is still considered largely incurable. According to the American Cancer Society, for all stages of pancreatic cancer combined, the one-year relative survival rate is 20%, and the five-year rate is 4%. When a cure is not possible, progression of the disease may be accompanied by worsening weakness, weight loss, and abdominal and back pain. Since the liver and pancreas share a common drain into the duodenum, many patients with advanced pancreatic cancer develop a blockage of the liver bile duct. If the liver can't drain properly, yellow liver bile backs up into the bloodstream and stains the skin yellow, a condition called jaundice. There are a variety of effective non-operative techniques available, such as ERCP, to treat bile duct obstruction and temporarily reduce jaundice. But even with modern advances in surgery and cancer treatment, the average life expectancy once the diagnosis of pancreatic cancer is made is usually less than six months.
How can you reduce your risk of pancreatic cancer?
To reduce risks for pancreatic cancer one should eliminate cigarette smoking and eat a diet high in fruits and vegetables. Also the main source of fat should be olive oil and fish. If this disease runs in your family, ask your doctor to refer you to a cancer specialist (oncologist) to discuss a screening program.
Unfortunately, there are currently no reliable early screening tests available. However, some "tumor markers" in the blood are used in an attempt to make an early diagnosis of pancreatic cancer. CA19-9 is the most studied tumor marker for following the progression of the disease but is only 80% accurate in identifying patients with pancreatic cancer. Even then, it does not usually detect the disease until it is advanced. Better screening and diagnostic techniques are urgently needed. When hereditary pancreatic cancer is suspected, other family members are often offered screening exams realizing that there is no proven screening. This may be a combination of xrays and blood work. Recently, there has been interest in using endoscopic ultrasound in an attempt to make an early diagnosis. There is much room for improvement in this field and research is underway at many major medical centers.