Treatment for large bowel and rectal NETs
The treatment you have for a large bowel or rectal neuroendocrine tumour (NET) depends on a number of factors. This includes where the cancer started, its size and whether it has spread (the stage).
Which treatment do I need?
A team of doctors and other professionals discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).
The treatment you have depends on:
- where the large bowel or rectal NET started and its size
- whether it has spread
- how the cells look under the microscope (the grade)
- the symptoms you have
- your general health
You are likely to have a clinical nurse specialist (or CNS). They go to the MDT meetings. They can help answer your questions and support you. They are often your main point of contact throughout your treatment.
Surgery for large bowel NETs
Endoscopic resection to remove a small part of the bowel lining
For a large bowel NET that is smaller than 1 cm, you usually have an endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). A surgeon or specialist doctor (colonoscopist) removes just the cancer and a border of healthy tissue around it. This is usually done when the NET is on the left side of the bowel.
Your doctor uses a long flexible tube (colonoscope) with a tiny camera and light on the end to look inside your bowel. They then remove the cancer by passing special instruments through the tube.
Surgery to remove a section of your bowel (colectomy)
You have a colectomy if your cancer is bigger than 2 cm and has grown through the muscle layer. Your surgeon removes the part of the bowel (colon) containing the tumour. How much your surgeon takes away depends on the exact position and size of the cancer.
Your surgeon might also remove the nearby lymph nodes.
Remember to click back to return to the neuroendocrine tumour section. The rest of the information in the bowel cancer section is not relevant to you.
Surgery for rectal NETs
Endoscopic resection to remove a small part of the rectum lining
For a rectal NET that is smaller than 1 cm, you usually have an endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). A surgeon or specialist doctor uses a long flexible tube (colonoscope) to remove just the cancer and a border of healthy tissue around it.
Surgery to remove a small part of the rectum
For a rectal NET that is between 1 and 2 cm, your surgeon might remove the cancer in an operation called a trans anal resection (or TEMS).
You usually have this operation in the operating theatre under a general anaesthetic. This means that you will be asleep and you won't feel anything.
Your surgeon uses special instruments to be able to see the rectum and remove the cancer.
Surgery to remove a section of the rectum (total mesorectal excision)
You have part of your rectum removed if the NET is bigger than 2 cm. Or if the cancer has spread to the area just outside the rectum (locally advanced NET). This operation is called total mesorectal excision. Your surgeon removes:
- the cancer
- a border of healthy tissue around the cancer
- some fatty tissue around the bowel
- a sheet of tissue called mesorectum
Remember to click back to return to the neuroendocrine tumour section. The rest of the information in the bowel cancer section will not apply to you.
Treatment for NETs that have spread to the liver
NETs of the large bowel and rectum can spread to other parts of the body. One of the most common places where it spreads to is the liver.
For NETs that have spread to the liver you might have:
You might be able to have the liver tumour removed at the same time you have the main surgery. Or you may have a second operation to remove it.
Your surgeon might remove just the tumour, or the part of the liver where the tumour is.
Radiofrequency ablation uses heat made by radio waves to kill cancer cells. You might have this treatment alone, or at the same time you have surgery for a large bowel or rectal NET.
Trans arterial embolisation aims to block the blood supply to a NET that has spread to the liver. The tumour can’t survive without a blood supply. Blocking the blood supply also stops the tumour releasing its hormones into the blood system. It’s also called hepatic artery embolisation.
Doctors might give a chemotherapy drug directly into the liver at the same time as blocking the blood vessel. This is called chemoembolisation or trans arterial chemoembolisation (TACE). This is a less common treatment for people with a neuroendocrine tumour.
A liver transplant is an operation to remove your liver and replace it with a healthy one from a donor. It is a big operation and is only suitable for a very small number of people. You doctor will let you know if this kind of operation is possible for you.
Remember to click back to return to the neuroendocrine tumour section. The rest of the information in the liver cancer section is not relevant to you.
Treatment to help with symptoms
You might have treatments to help with symptoms if:
- you can’t have surgery to remove the tumour
- the NET has spread to another part of the body
- the NET came back after the initial treatment
These treatments can control your symptoms and help you feel better, but won’t get rid of the NET. Treatment you might have include:
You might have a type of internal radiotherapy called peptide receptor radionuclide therapy (PRRT). Internal radiotherapy means having radiotherapy from inside the body.
PRRT uses a radioactive substance called lutetium-177 or yttrium-90. Neuroendocrine cells have proteins on the outside of them called somatostatin receptor proteins. The hormone somatostatin attaches itself to this receptor protein and normally would slow down the production of hormones by the cell.
By attaching the radioactive substance to a man made form of the hormone somatostatin (a somatostatin analogue) it can deliver the radiotherapy directly inside the neuroendocrine cell and destroy it.
Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. You may have it if the large bowel or rectal NET continued to grow despite having other treatments. You might have:
- fluorouracil (5-FU)
- capecitabine
- streptozocin
You may also have carboplatin and etoposide if you have a high grade NET. A high grade NET means that the cells look very abnormal and not like normal cells.
Cancer cells have changes in their genes (DNA) that make them different from normal cells. These changes mean that they behave differently. Targeted drugs work by ‘targeting’ the differences that a cancer cell has and destroying them.
You may have a type of targeted drug called everolimus.
Somatostatin is a protein made naturally in the body. It does several things including slowing down the production of hormones. Somatostatin analogues are man made versions of somatostatin.
You may have somatostatin analogues to try to slow down the tumour and help with symptoms. They include:
- octreotide (Sandostatin)
- lanreotide (Somatuline)
You usually have somatostatin analogues if your large bowel or rectal NET picks up somatostatin. Doctors can check for this using special scans. This isn't common for large bowel and rectal NETs, so not everyone can have this treatment.
Clinical trials
Doctors are always trying to improve treatments, and reduce side effects. As part of your treatment, your doctor might ask you to take part in a clinical trial. This might be to test a new treatment or to look at different combinations of existing treatments.
