SURGERY  FOR  CANCER  OF  THE  PANCREAS

Introduction

Cancer of the pancreas is currently the fifth leading cause of cancer-related death in the United States. In fact, it is associated with the lowest survival rate of any cancer. Why is it such a fatal disease? When it is diagnosed, the cancer is usually in the late stages, meaning that it has already spread to various organs of the body. This makes complete cure extremely difficult. Only 15 to 20% of patients with pancreatic cancer are diagnosed early enough so that the cancer is still confined to the pancreas. For these patients, surgical resection (removal) of the cancer is the best option for treatment. The good news is that while pancreatic resection was formerly associated with a high rate of complications and even death, it has evolved into a much safer procedure. This article will focus on the surgical treatment of patients with potentially curable pancreatic cancer.

Usually specialized tests are required to ensure that the cancer has not spread to other organs and is still confined to the pancreas. Most of these tests are imaging tests that yield a characteristic picture of the anatomy in question. One of these tests actually involves investigative surgery.

Spiral Computed Tomography

Spiral computed tomography scanning (ˇ°spiral CTˇ±) is considered the best initial test for detecting pancreatic cancer. It is relatively inexpensive, noninvasive, and very effective at diagnosing the cancer and determining the extent of spread. In spiral CT, the patient lies down on a movable table. A special dye is injected into the veins. As the patient is passed through a large ring, images of cross-sectional planes of the body are obtained. The patient's own cardiovascular system pumps the dye through the blood vessels so that certain tissues of the body are illuminated on the images. Spiral CT is almost 100% effective at showing large tumors of the pancreas (greater than 15 mm), but less effective for smaller masses. Overall, spiral CT can detect pancreatic cancer 85 to 95% of the time.

The technique is also good at determining whether the cancer has invaded major blood vessels (arteries or veins). If so, the tumor is much less likely to be resectable. A recent study in 25 patients with pancreatic cancer found that if the cancer invaded less than 25% of the circumference of a major artery or vein, the cancer could be surgically resected. But if the tumor involved more than half of the circumference of the vessel, it was usually unresectable.

As no test is perfect, spiral CT has its limitations. It does not always detect if the cancer has spread to the liver or to the peritoneum (the smooth membrane that lines the walls of the abdominal cavity and folds inward to enclose the abdominal organs). Also, it cannot definitively determine if an enlarged lymph node is cancerous or not.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is an alternative imaging test useful for patients who are allergic to the injection dye required for spiral CT. It is also helpful when pancreatic cancer is not detected by spiral CT but is still suspected for other reasons. MRI is approximately equivalent to spiral CT with regard to detecting pancreatic cancer and determining whether the tumor has invaded blood vessels. Special techniques allow visualization of the bile ducts and pancreatic ducts, which may allow detection of cancer that is localized to these ducts.

Positron-Emission Tomography

Positron-emission tomography (PET) is a newer imaging method that takes advantage of the increased uptake of glucose by pancreatic cancer cells. After the glucose molecules are tagged with a small amount of radioactivity and are taken up by the cancer cells, the PET scanner detects the radioactivity to make an image. This can help localize areas in the liver, lymph nodes, or peritoneum where the cancer has spread.

Endoscopic Procedures

Endoscopic procedures involve the use of an endoscope - a thin, flexible, well-lit tube for visually examining the interior of a bodily canal or a hollow organ such as the gastrointestinal tract, bladder, or airways.

Endoscopic ultrasound (EUS) allows the operator to introduce a small ultrasound probe into the small intestine where the pancreas secretes its juices. The ultrasound probe emits ultrasonic sound waves and records the pattern in which the waves are reflected back by the body's tissues, thus creating an image. EUS can be useful in detecting pancreatic cancers if the CT scan is not definitive. With EUS as a guide, a fine needle can be used to aspirate cells from a pancreatic mass in order to confirm the diagnosis of cancer.

Endoscopic retrograde cholangiopancreatography (ERCP) is another endoscopic procedure which involves injecting dye into the pancreatic duct from the opening in the small intestine to obtain images of the pancreatic duct. Sometimes pancreatic cancer is initially confined to the inside of the duct.

Laparoscopy

In the treatment of pancreatic cancer, the first question to answer is if the tumor may be safely resected with reasonable benefit to the patient. Resection may be impossible if the cancer involves certain blood vessels or has spread widely. If conventional imaging or endoscopic procedures fail to provide enough information, further invasive testing with laparoscopy may be required. Laparoscopy is a surgical procedure that allows the surgeon to directly assess the tumor, lymph nodes, peritoneum, and other abdominal organs without making a large incision in the abdomen. An ultrasound probe may be used during the procedure. If the tumor appears resectable, and the patient is healthy enough to tolerate the operation, surgery remains a viable option. If the cancer is unresectable, then the patient may be spared further surgery at the least. However, the role of laparoscopy may diminish as the technology for CT scans improve.

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AUTHOR: Kevin Hwang, MD
Reviewed by Jiade J. Lu, MD
The Cancer Information Network
Date Modified: 04/05/02