Neuroendocrine Tumors – An Introduction

Last Updated: June 9, 2020

A neuroendocrine tumor (NET) is a cancerous tumor that begins in the specialized cells of the body’s neuroendocrine system. These cells have traits of both hormone-producing endocrine cells and nerve cells. In this video, Dr. Pamela Kunz explains the basics of NETs, including staging, grading, and treatment options.

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Cancer.Net: Doctor-Approved Patient Information from ASCO®

Neuroendocrine Tumors – An Introduction

Voiceover: A neuroendocrine tumor can start in almost any organ throughout the body. These tumors are cancerous. They begin in the specialized cells of the body's neuroendocrine system. And this type of tumor most commonly occurs in the gastrointestinal, or GI, tract, as well as the lungs and pancreas.

Illustration of the body’s organs shows the gastrointestinal tract, the lungs, and the pancreas.

Pamela Kunz, MD; Medical Oncologist; Member, American Society of Clinical Oncology (Filmed June 2019):  "Neuroendocrine tumors" is a bit of a mouthful and so we will often use the abbreviation "NET," N-E-T, when we refer to neuroendocrine tumors. They get their name "neuroendocrine" because they can secrete hormones. About probably 20 to 40 percent of these cancer types secrete hormones and it does depend on where they originate and whether they secrete hormones or not. These also tend to be slower growing cancers so the number of patients alive at any given time is actually quite high, as patients are alive and living with their neuroendocrine tumors for quite a while. It is a very hopeful time in this particular field. So when I meet a new patient now, compared to when I met a new patient ten years ago, I have so many other therapies that I can offer.

Voiceover: When diagnosed with a neuroendocrine tumor, there are several important questions to ask your oncologist.

Dr. Kunz: Patients should ask their doctor, where did my cancer start? The second would be, is my cancer localized, or has it spread? That will also affect the treatments, which whe can talk about in a little bit. For example, if the cancer is localized to the pancreas, a surgery would be something that could be considered. If it’s, however, spread to the liver or the lungs, the treatment needs to be more systemic. And then the third question would be, what is the grade of my tumor?

NET Questions to Ask

  • Where did my cancer start?

  • Has my cancer spread?

  • What is the grade of my tumor?

Voiceover: When talking to your doctor it is important to understand that stage and grade are different. Stage refers to if, or where in the body the cancer has spread and grade refers to what the cancer cells look like when the when the pathologist looks at them under the microscope.


Where in the body the cancer has spread.


What the cancer cells look like.

Dr. Kunz: For neuroendocrine tumors, grade is put into three main buckets: grade 1, grade 2, and grade 3. Grade 1 and 2 tend to be the lower growing tumors, and grade 3 arethe faster growing tumors.

Grade One & Two

Slower growing tumors

Grade Three

Faster growing tumors

Dr. Kunz: And so grade 1 and 2 are treated similarly and grade 3 has a separate set of treatments. Grade 1 and 2 are the lower grade tumors. They have a number of treatments, and in fact, in the last decade, we’ve had about seven new FDA approvals. So it’s really been an active area of investigation and new therapies, which I think is very exciting and I think provides a lot of hope for patients. One of the main treatments for neuroendocrine tumors is a class of medications called somatostatin analogues. These include two medications. One is octreotide and the other is lanreotide. They are more of a hormone treatment and they are at once-a-month injection. They serve two purposes. They can help slow down secretion of hormones, but they can also slow down the growth of these cancers. We would not generally expect them to shrink the cancer, but stability is still a win for patients who have metastatic disease.

Voiceover: There were also other types of treatments, including systemic therapies, called biologic therapies, used to treat neuroendocrine tumors.

Dr. Kunz: Everolimus is a daily pill that's approved for lung neuroendocrine tumors, small bowel neuroendocrine tumors and pancreatic NETs. And this pill also at best would yield stability, it also does not generally shrink the cancer. And then for pancreatic NETs, we have another biologic or targeted therapy called sunitinib. And that is also a pill and it blocks the vascular endothelial growth factor pathway, which is a blood vessel pathway. And then more recently we've had an FDA approval of a brand new class of therapy. The overall class is called PRRT, or peptide receptor radionuclide therapy. It is—think of it like one of those somatostatin analogues, like octreotide, linked with a dose of radiation. It's given via infusion. It was just FDA-approved about a year ago, and has the chance of both slowing down the growth of neuroendocrine tumors, and also about one in five patients had a reasonable tumor shrinkage. This was FDA-approved for patients with gastroenteropancreatic NETS, so primarily GI and pancreas.

So the sequencing of therapies, I think is a really important question that is being studied in some clinical trials. So for example, do you start with chemotherapy first, or do you start with this peptide receptor radionuclide therapy first?

Voiceover: Grade three neuroendocrine tumors are treated differently than grades one and two because of their more aggressive nature.

Dr. Kunz: Those patients tend to have more fast-growing disease, they tend to need only chemotherapy. So IV chemotherapies that are often used for that patient population are platinum and etoposide IV chemotherapies. This is also a very active area of research.

Voiceover: For the latest information on neuroendocrine tumors, you can visit Cancer.Net, the patient education website from ASCO, the American Society of Clinical Oncology.

Dr. Kunz: Cancer.Net can be an incredible resource. It has included some of the recent treatments and advances, FDA approvals, and diagnostics.

[Closing and Credits]

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