Although it is the tenth most common cause of cancer in the U.S., pancreatic cancer is the fourth leading cause of cancer deaths and has an overall survival rate of less than 4%.
The only potentially curable patients are those whose tumor is truly confined to the pancreas, but this represents only 20% of pancreatic cancer patients. For this reason, it is critical to identify and diagnose patients as early in the course of their disease as possible in order to increase the success of treatment.
More than 90% of pancreatic tumors are exocrine carcinomas. The most common histology is adenocarcinoma. Pancreatic tumors may develop in the head, body or tail of the pancreas. Those in the body or tail often do not cause symptoms until late in the course of the disease. Pancreatic tumors in the head of the pancreas lead to bile duct obstruction and jaundice earlier in the disease and are more often amenable to surgical resection.
Common Signs and Symptoms
The early common signs and symptoms of pancreatic cancer are quite non-specific and may be attributable to other more benign conditions, such as pancreatitis or reflux. As such, the diagnosis is often delayed in patients, with 70 to 80% presenting with widespread disease at the time of diagnosis.
Presence of the following, particularly in elderly patients with a smoking history (the most common risk factor), should alert clinicians to the possibility of pancreatic cancer:
- Jaundice (yellowing of the skin due to a blocked bile duct; often accompanied by itching)
- Unexplained Weight Loss
- Floating Stools (this indicates malabsorption of fats due to pancreatic insufficiency)
- Early Satiety
- Epigastric and/or Abdominal Pain
Other Signs and Symptoms
Pancreatic cancer can result in the onset of diabetes. It should be considered in the differential in an elderly patient who suddenly develops diabetes. Pancreatic cancer can also develop in patients who already have diabetes. This should be a particular concern in diabetics who develop abdominal symptoms and continued weight loss.
Because of the location of the pancreas in the upper abdomen, pancreatic tumors often involve the celiac plexus nerves. As such, chronic pain commonly accompanies this diagnosis, and it may be severe. There are two general treatment approaches: surgical intervention and oral analgesics. For surgical intervention, an EUS- or CT-guided celiac plexus neurolysis (or block) is performed. This involves injection of a local anesthetic directly into the affected nerves. The procedure is not overly invasive and can result in significant pain relief for many weeks. For patients who do not respond to or are not candidates for a celiac plexus block, strong opioid analgesics are the drugs of choice. The gold standard is long-acting oral morphine, but there are many options, including other oral agents and transdermal patches. With these strategies, the vast majority of pancreatic cancer patients can achieve excellent pain control.
Pancreatic insufficiency is caused by tumor destruction of normal pancreatic tissue and/or the pancreatic ducts. It is also an obvious complication of surgical resection of the pancreas. The most common symptom of pancreatic insufficiency is malabsorption of fat due to the lack of pancreatic enzymes. This is also called steatorrhea. The stools will be oily in appearance and float. Treatment is relatively simple: Patients take oral replacement pancreatic enzymes with each meal. The dose is titrated to each individual’s dietary fat intake, and the replacement enzymes have few side effects.
Biliary obstruction occurs in two-thirds of patients with pancreatic cancer. The bile ducts allow enzymes produced by the pancreas and bile produced by the liver to flow into the duodenum. Blockage leads to jaundice (see Common Signs and Symptoms) and can ultimately damage normal pancreatic and liver tissue. Biliary obstruction is managed by placing a biliary stent to keep the bile ducts open. If the patient undergoes pancreatic resection, the surgeon may opt to perform a biliary-enteric bypass during the surgery.
GASTRIC OUTLET OBSTRUCTION
Gastric outlet obstruction is a less common complication of pancreatic cancer. It occurs in 10 to 25% of patients and is due to tumor-compression of the pylorus (the connection between the stomach and the duodenum). Symptoms include severe vomiting, often not preceded by nausea, as well as abdominal pain. Gastric outlet obstruction is managed by placing a stent to keep the pylorus open or by performing a gastrojejunostomy, which connects the stomach to the jejunum and bypasses the duodenum. To aid with nutrition, a J-tube may be placed in the small intestine. This tube allows liquid nutrition to be delivered despite the obstruction.
Patients with pancreatic cancer have a significantly increased risk of developing blood clots in the veins of the legs (so-called DVTs). This in itself is not a fatal complication. The concern is that parts of the clot may break off and go to the lungs (pulmonary emboli), which is very often fatal. This complication is sometimes referred to as Trousseau’s syndrome. For patients who develop a DVT, treatment options include blood thinners such as warfarin or enoxaparin. These drugs are usually recommended to be continued indefinitely in cancer patients, once a blood clot has developed.