Surgery for Gastric Neuroendocrine Tumors

If you’ve been diagnosed with a gastric neuroendocrine tumor (NET) and are discussing treatment options with your cancer care team, your doctors may recommend surgery as part of your treatment plan. While the intricate details about surgery and its procedures can leave you feeling confused and overwhelmed, understanding how this type of treatment works is very useful. Not only will it help you stay on top of medical discussions, it can also prepare you for what to expect during your treatment journey.

Surgery is a type of treatment where a part of your body is cut open by your doctors to remove, repair or replace diseased or damaged tissue.

Depending on factors such as the type and grade of the NET, the aim of surgery could be either curative or palliative.

Curative

Surgery is currently the only possible way to effectively remove NETs completely. This explains why it is traditionally the first-line of treatment for NETs and recommended by doctors whenever possible.

Curative surgery is achieved by removing the tumor(s) entirely. Early-stage, low-grade gastric NETs that are localized (i.e. contained within the stomach) can often be cured with surgery. Curative treatment is sometimes possible for tumors with limited spread to nearby tissues. This is known as regional spread.

Palliative

When the cancer has spread to distant parts of the body and cannot be removed completely and safely with surgery, curing the disease is unlikely. The goal of surgery is then to relieve symptoms and slow tumor progression. This is known as palliative surgery. It is often used to treat unresectable low and intermediate-grade (G1 or G2) metastatic NETs.

Palliative surgery includes either of two approaches:

• Debulking (or cytoreductive) surgery: This involves removing as much tumor tissue as possible. Debulking helps to improve symptoms and control the growth of larger tumors. It can also make medical therapies, such as hormone therapy, more effective by reducing circulating hormones and shrinking the tumor.
• Bypass (or palliative) surgery: In some instances, the NET may develop too close to blood vessels and/or nearby organs. This can interfere with how these vital structures work and potentially cause symptoms like abdominal pain or pressure. Creating a bypass or passage to go around these tumors can help to prevent blockages and lower the chances of future complications.

Be it debulking or bypass surgery, the primary gastric tumor should be removed if possible. This lowers your risk of developing localized complications and can prevent further spread of the cancer.

When deciding which type of procedure is best for your condition, your doctors will take several factors into consideration. This includes the size and location of the gastric NET, whether it has spread and your overall health.

There are various types of surgical operations used in the treatment of primary NETs of the stomach, which are endoscopic resection (ER), local excision (wedge resection) and partial or total gastrectomy.

Endoscopic resection (ER)

Minimally-invasive procedures of this sort involve the insertion of a thin, tube-like instrument called an endoscope down the esophagus and into the stomach. Surgical cutting tools passed through the tube are then used to remove the tumor.

ER procedures are usually performed under conscious sedation. This means you will be administered sedatives through your vein (intravenous) to keep you relaxed and sleepy, but not unconscious. You will still be able to hear what your doctors or nurses are saying to you and carry out simple instructions. While you may feel slight movement or pressure, you shouldn’t feel any pain and you might not be fully aware of what goes on during the procedure. You may also be given anesthetic spray beforehand to numb your throat. This makes it easier for the endoscope to pass through your throat and into the esophagus.

There are two types of ER procedures — endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). Both are typically used to treat stomach carcinoid tumors of 1 to 2 cm that are contained within the stomach mucosa or submucosa. These NETs are almost always successfully treated with surgery alone.

Local excision (or wedge resection)

In this operation, surgical incisions are made in your abdomen through which the primary gastric tumor(s) and some surrounding healthy tissue are removed. The edges are then sewn together. Compared to ER procedures, local excisions are performed under general anesthesia. This means you’ll be put to sleep and will be unconscious during surgery.

Local excisions are typically done for carcinoid tumors that are no larger than 2 cm, confined to the stomach mucosa or submucosa but technically difficult to remove via endoscopy. This happens when the anatomic position of the tumor within the stomach is unfavorable.

Partial or total gastrectomy

Tumors that are larger than 2 cm, growing into deeper layers of the stomach wall or spreading to nearby lymph nodes usually require more extensive surgery, such as a gastrectomy. A gastrectomy is a surgical procedure where all or part of the stomach is removed. Depending on the location of the NET in your stomach and how far it has spread, your doctors will decide if you are due for a partial or total gastrectomy. In a partial gastrectomy, only part of your stomach is removed whereas a total gastrectomy involves the removal of the entire organ.

> Find out more about partial and total gastrectomy here

While most gastric NETs are slow-growing, some tumors can spread to other parts of the body. The most common site of cancer spread is the liver. When this happens, circulating hormones, which are responsible for causing symptoms of carcinoid syndrome like flushing and diarrhea, can no longer be metabolized by the liver. This explains why carcinoid syndrome is more common among those with NETs that have spread to this particular organ.

Apart from removing the primary tumor in the stomach, surgical operations targeting liver metastases are important too. While they may not cure the cancer completely, these procedures can help to relieve the symptoms of carcinoid syndrome.

Liver resection

Potentially curative surgery can be done if there is limited cancer spread in the liver (i.e. only one or two tumors). This procedure is known as a liver resection, where all cancerous parts of the liver are removed completely. Curative resection is possible in approximately 10% of all liver metastases cases.

Cytoreductive surgery

If it is not possible to remove all areas affected by the cancer, your doctors may still perform cytoreductive surgery to remove as much tumor tissue as they can. This is also known as debulking. Examples of such procedures include liver-directed therapies such as ablation and embolization.

> Find out more about liver-directed therapies here

Cytoreductive surgery is generally considered palliative care. However, if your doctors believe that your cancer can be completely destroyed with the use of other medical treatments, cytoreductive surgery can make these treatments work more effectively.

Liver transplant

If you have liver-only metastatic disease and the NETs in the liver cannot be removed completely, you may be offered a liver transplant. This procedure involves removing your diseased liver and replacing it with healthy donated liver. A liver transplant is rarely recommended as a treatment option, unless you are suffering from life-threatening uncontrolled carcinoid syndrome and are not responding to multiple systemic treatments.

There are a few surgical approaches that your doctors can take when performing an operation, which include:

Open surgery

To access your stomach, a single, large incision (cut) or laparotomy is made in the upper part of your abdomen, just below the breastbone down to the belly button. This allows your surgeons to remove, debulk or bypass your cancer, after which the incision is closed with staples or sutures.

Laparoscopic (or keyhole) surgery

This surgical approach is typically offered in specialist cancer centers with specially trained surgeons. During this minimally-invasive procedure, several small incisions are first made in the abdomen. Through one of the incisions, your surgeon will insert a thin, lighted tube with a tiny video camera at its tip. This is known as a laparoscope. The use of this instrument allows images of the inside of your abdomen to be projected on a screen, which your surgeon uses for guidance as they perform the operation. Through the other incisions, long surgical tools are inserted and used to remove, debulk or bypass your cancer.

Robotic surgery

This minimally-invasive procedure involves an advanced surgical device with surgical instruments mounted on the ends of robotic arms. An additional arm consists of a camera that generates magnified, high-definition, three-dimensional images of the inside of your abdomen. These images are displayed on a screen to help guide your surgeon during the procedure. After inserting the surgical instruments and camera through small abdominal incisions, your surgeon controls these tools from a console in the operating room and uses them to carry out the procedure.

If you have any questions about surgery and whether you are a good candidate for one, please consult your doctors and cancer care team.