Surgery for Pancreatic Neuroendocrine Tumor

Two general types of surgery can be used for pancreatic neuroendocrine tumors (NETs):

• Potentially curative surgery is used when the results of exams and tests suggest that it’s possible to remove (resect) all the cancer.
• Palliative surgery may be done if imaging tests show that the cancer is too widespread to be removed completely. This surgery is done to reduce tumor size to relieve symptoms from excess hormone production or to prevent certain complications like a blocked bile duct or intestine. The goal is not to try to cure the cancer.

To know if the cancer can be surgically removed, it is staged before the surgery, and sometimes, during the surgery.

• Staging before surgery: This uses imaging tests such as CT scans, MRI scans, and/or radionuclide scans, to see if the cancer has spread beyond the pancreas, both locally and distantly. Exploratory laparoscopy may also be done to help determine if the cancer has spread and if it can be resected. For this procedure, the surgeon makes a few small incisions (cuts) in the abdomen (belly) and inserts long, thin instruments. One instrument has a small video camera on the end so the surgeon can see inside the abdomen. The surgeon can look at the pancreas and other organs for tumors and take biopsy samples of abnormal areas to learn how far the cancer has spread.
• Staging during surgery: Even after imaging tests are completed, the pancreas may still need to be looked at closely to understand if the tumor can be removed safely. In these cases, intraoperative imaging, such as an intraoperative ultrasound, will need to be done. Intraoperative ultrasound is used during the surgery to better understand structures near the pancreas tumor.

Potentially curative surgery

Pancreatic NETs that have not spread outside the pancreas should be completely removed, if possible, because these tumors are more likely to be cured with surgery.  Sometimes, however, after the surgeon starts the operation it becomes clear that the cancer has grown too far to be completely taken out. If this happens, the operation may be stopped, or the surgeon might continue with a smaller operation to help prevent or relieve symptoms. (See “Palliative surgery” below.) This is because the planned operation would be very unlikely to cure the cancer and could still lead to major side effects. It would also make the recovery time longer, which could delay other treatments.

Many of these types of surgery are complex and can be very hard for patients. They can cause complications and can take weeks or months to make a full recovery. If you're thinking about having this type of surgery, it’s important to weigh the potential benefits and risks carefully.

Types of potentially curative surgery include:

• Enucleation (removing only the tumor)
• Central pancreatectomy
• Distal pancreatectomy
• Whipple procedure (pancreaticoduodenectomy)
• Total pancreatectomy

The type of surgery needed depends on several factors, including the location, size, and specific kind of pancreatic NET (functioning or nonfunctioning).

Enucleation (removing just the tumor)

Sometimes if a pancreatic NET is small, just the tumor itself is removed. This is called enucleation. This operation may be done using a laparoscope, so that only a few small cuts on the belly are needed.

This operation may be an option for patients with an insulinoma or a gastrinoma that is smaller than 2 cm (less than 1 inch), since these PNETs are believed to be less aggressive. For PNETs that are located close to the common bile duct or pancreatic duct, are larger than 3 cm (a little more than an inch), and are suspected of having spread to nearby lymph nodes, enucleation is commonly not the first surgical approach.

Central pancreatectomy

A central pancreatectomy is a surgical option for small, low-grade PNETs that are located in the neck or upper body of the pancreas, if enucleation can not be safely done. During this operation, the surgeon removes only the neck and upper body of the pancreas, keeping the pancreatic head and tail intact. This helps keep most of the functions of the pancreas.

Distal pancreatectomy

A distal pancreatectomy is used to treat pancreatic NETs found in the tail and body of the pancreas. In this operation, the surgeon 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, but can be saved in certain situations. The spleen helps the body fight infections, so if it’s removed you’ll be at increased risk of infection with certain bacteria. To help with this, doctors recommend that patients get certain vaccines before havingthis surgery.

Whipple procedure (pancreaticoduodenectomy)

A Whipple procedure is used to treat pancreatic NETs found in the head of the pancreas that cannot be removed by enucleation. During this operation, the surgeon removes the head of the pancreas and sometimes the body of the pancreas as well. Nearby structures such as part of the small intestine (duodenum), part of the bile duct, the gallbladder, lymph nodes near the pancreas, and sometimes part of the stomach are also removed. The remaining bile duct and pancreas are then attached to the small intestine so that bile and digestive enzymes can still go into the small intestine. The small intestine (or the stomach and small intestine) is then reattached so that food can pass through the digestive tract.

Most often, this operation is done through a large incision (cut) down the middle of the belly. Some doctors at major cancer centers also do the operation laparoscopically, which is sometimes known as keyhole surgery .

This is a very complex operation that requires a surgeon with a lot of skill and experience. It carries a relatively high risk of complications that can be life threatening. When the operation is done in small hospitals or by doctors with less experience, as many as 15% of patients may die as a result of surgical complications. In contrast, when the operation is done in cancer centers by surgeons experienced in the procedure, less than 5% of patients die as a direct result of surgery.

In general, people having this type of surgery do better when it's done at a hospital where at least 15 to 20 Whipple procedures are done per year.

Still, even under the best circumstances, many patients have complications from the surgery. These can include:

• Leaking from the various connections between organs that the surgeon has joined
• Infections
• Bleeding
• Trouble with the stomach emptying after eating
• Trouble digesting some foods (which might require taking pancreatic enzymes in pill form to help with digestion)
• Weight loss
• Changes in bowel habits
• Diabetes

Total pancreatectomy

Total pancreatectomy might be an option if the cancer has spread throughout the pancreas but can still be removed. This operation removes the entire pancreas, as well as the gallbladder, part of the stomach and small intestine, and the spleen. But this type of surgery is used less often than the other operations because there doesn’t seem to be a major advantage in removing the whole pancreas, and it can have major side effects.

It’s possible to live without a pancreas. But when the entire pancreas is removed, people are left without the cells that make insulin and other hormones that help maintain safe blood sugar levels. These people develop diabetes, which can be hard to manage because they are totally dependent on insulin shots. People who have had this surgery also need to take pancreatic enzyme pills to help them digest certain foods.

Before you have this operation, your doctor will recommend that you get certain vaccines because your spleen will be removed.

Palliative surgery

If the cancer has spread too far to be removed completely, any surgery being considered would be palliative (intended to relieve symptoms and improve your quality of life). This type of surgery may be considered in some people with pancreatic NETs whose tumor has recurred and is causing local problems or is making too many hormones that are causing symptoms. 

Sometimes surgery might be started with the hope it will cure the patient, but once it begins the surgeon discovers this is not possible. In this case, the surgeon might do a less extensive, palliative operation known as bypass surgery instead to help prevent or relieve symptoms.

Cancers growing in the head of the pancreas can block the common bile duct as it passes through this part of the pancreas. This can cause pain and digestive problems because bile can’t get into the intestine. The bile chemicals will also build up in the body, which can cause jaundice, nausea, vomiting, and other problems.

There are 2 main options for relieving bile duct blockage: stent placement, and bypass surgery.

Stent placement

The most common approach to relieving a blocked bile duct does not involve actual surgery. Instead, a stent (small tube, usually made of metal) is put inside the duct to keep it open. This is usually done through an endoscope (a long, flexible tube) while you are sedated. Often this is part of an endoscopic retrograde cholangiopancreatography (ERCP). The doctor passes the endoscope down the throat and all the way into the small intestine. The doctor can then insert the stent into the bile duct through the endoscope. The stent can also be put in place through the skin during a percutaneous transhepatic cholangiography (PTC). (This is described in Tests for Pancreatic Neuroendocrine Tumor.)

The stent helps keep the bile duct open even if the surrounding cancer presses on it. But after several months, the stent may become clogged and may need to be cleared or replaced.

A bile duct stent can also be put in to help relieve jaundice (a yellowing of the skin and whites of the eyes) before curative surgery is done (which would typically be a couple of weeks later). This can help lower the risk of complications from surgery.

Larger stents can also be used to keep parts of the small intestine open if they are in danger of being blocked by the cancer.

Bypass surgery

In people who are healthy enough, another option for relieving a blocked bile duct is surgery to reroute the flow of bile from the common bile duct directly into the small intestine, bypassing the pancreas. This typically requires a large incision (cut) in the abdomen, and it can take weeks to recover from this. Sometimes surgery can be done through several small cuts in the abdomen using special long surgical tools (laparoscopicsurgery).

Having a stent placed is often easier and the recovery is much shorter, which is why it is done more often than bypass surgery. But bypass surgery can have some advantages:

• It can often give longer-lasting relief than a stent, which might need to be cleaned out or replaced.
• It might be an option if a stent can’t be placed for some reason.
• During surgery, the surgeon may be able to cut some of the nerves around the pancreas or inject them with alcohol. This may reduce or get rid of any pain caused by the cancer.

Sometimes, the end of the stomach is disconnected from the duodenum (the first part of the small intestine) and attached farther down the small intestine during this surgery as well. (This is known as a gastric bypass.) This is done because over time the cancer might grow large enough to block the duodenum, which can cause pain and vomiting and often requires urgent surgery. Bypassing the duodenum before this happens can sometimes help avoid this.

Bypass surgery can still be a major operation, so it’s important that you are healthy enough to withstand it and that you talk with your doctor about the possible benefits and risks before you have the surgery.

Surgery for cancer that has spread

Surgery may be used to remove metastases if a pancreatic NET has spread to the liver (the most common site of spread) or the lungs. Surgically removing metastases can improve symptoms and help patients with pancreatic NETs live longer.