On This Page – Quick Medical Summary
A pancreatic neuroendocrine tumor (pNET) grows from the islet cells of the pancreas, the cells that make hormones such as insulin. Those are different cells from the duct cells that give rise to the far more common pancreatic adenocarcinoma. When a pNET is found before it has spread beyond the pancreas, people are on average about 91% as likely to be alive five years later as people without the tumor, based on American Cancer Society survival figures.
That difference in cell type shapes the tests you will have and the treatments you will be offered.
This is not the pancreatic cancer you may have read about
Search results for “pancreatic cancer” mostly describe adenocarcinoma, a different disease with a much poorer outlook. pNETs are rare by comparison, and grade 1 and grade 2 tumors tend to grow slowly. The symptoms and stages of the more common type follow a different pattern from the one described here.
More pNETs are diagnosed each year than in the past. Part of the reason is that CT and MRI scans done for unrelated problems now pick up small tumors that once went unnoticed.
No one knows what triggers most pNETs, and there is no known way to prevent one. Nothing you did or didn’t do caused it.
Four lines on your pathology report that shape everything
Pull out your pathology and imaging reports and look for four details. Together they predict how the tumor is likely to behave far better than the word “pancreatic” does.
| Report detail | What you might see | What it tells your team |
|---|---|---|
| Differentiation | Well-differentiated neuroendocrine tumor (NET), or poorly differentiated neuroendocrine carcinoma (NEC) | NET is the usual pNET. NEC is a separate, high-grade cancer with its own treatment plan. |
| Grade and Ki-67 | G1: Ki-67 under 3% · G2: 3–20% · G3: over 20% | Ki-67 is the share of tumor cells preparing to divide. A higher grade means faster growth. |
| Size | Centimeters, measured on CT, MRI or endoscopic ultrasound | 2 cm is the cutoff specialists use when weighing surveillance against surgery. |
| Spread | Localized, regional (nearby tissue or lymph nodes) or distant (liver, lungs, bone) | The strongest single influence on survival figures |
Grading cutoffs: Endotext review of pancreatic neuroendocrine neoplasms. Spread categories: American Cancer Society.
Pathologists also count dividing cells under the microscope. Fewer than 2 per 2 mm² of tissue fits grade 1, 2 to 20 fits grade 2, and more than 20 fits grade 3.
Sample report (invented values for illustration): “Pancreatic tail mass, EUS-guided fine-needle biopsy. Well-differentiated neuroendocrine tumor, WHO grade 2. Ki-67 proliferation index 8%.” The CT report describes a 2.6 cm mass with no liver lesions.
Read together, this is an intermediate-grade tumor. It is larger than the 2 cm surgical threshold and appears to be confined to the pancreas. A team would usually look for hidden spread with a specialized PET scan and then discuss surgery. Swap in a 1.2 cm grade 1 tumor that releases no hormones and causes no symptoms, and regular scans instead of an operation could become a reasonable plan.
Does your tumor make hormones?
Most don’t. Tumors that release no excess hormone are called nonfunctional, and they outnumber the functional kind. With no hormone symptoms to give them away, they are often large by the time they are found. They are also more likely than functional tumors to behave as cancer.
Functional tumors are named for the hormone they overproduce. Insulinoma, the most common functional type, drives blood sugar down and causes weakness, headache, blurred vision and fatigue. Most insulinomas grow slowly and are not cancer. Gastrinoma floods the stomach with acid, leading to reflux, ulcers that keep returning, belly or back pain and diarrhea, and most gastrinomas are cancer.
Glucagonomas and VIPomas are rarer still.
Get emergency care now if: you become confused, slur your speech, have a seizure or pass out, especially with a known insulinoma or another cause of dangerously low blood sugar. The same applies if you vomit blood or pass black, tarry stools, or have severe watery diarrhea with dizziness and very little urine. Call 911.
Tests you will likely have next
A somatostatin receptor PET scan is the imaging test designed most specifically around pNETs. Somatostatin receptors are common on these tumors, and the scan’s tracer attaches to them, showing where tumor deposits sit. On your order the tracer may be listed as Ga-68 DOTATATE, Cu-64 DOTATATE or Ga-68 DOTATOC.
The scan is less reliable for insulinomas and high-grade tumors. A positive result also tells your team whether somatostatin-analog drugs or radionuclide therapy are likely to help (American Cancer Society guide to pNET tests).
CT or MRI with contrast dye maps the tumor and checks the liver. An endoscopic ultrasound (EUS) passes a thin scope through the mouth into the small intestine, right beside the pancreas. A needle passed through the scope collects cells to confirm the diagnosis and measure Ki-67. Blood work may include chromogranin A and pancreatic polypeptide. When symptoms point to a specific hormone, such as insulin, gastrin, glucagon or VIP (vasoactive intestinal peptide), that hormone is measured too.
Inherited (germline) genetic testing belongs on the list as well. About 1 in 10 pNETs is linked to an inherited syndrome such as MEN1, von Hippel-Lindau disease, neurofibromatosis type 1 or tuberous sclerosis. One study of 238 people with pNETs at two US cancer centers tested 106 of them regardless of family history. Of those 106, 21% carried a disease-causing variant, most often in MEN1 or DNA repair genes, and the authors called for offering testing to everyone with a pNET.
A positive result can affect later treatment and follow-up, and close relatives may want testing too. The process is described in genetic testing for pancreatic tumors.
Watch, operate or treat with medicine
Three facts drive the choice: whether the tumor makes hormones, its size and grade, and whether it has spread.
A small, low-grade tumor that releases no hormones and causes no symptoms can often be watched instead of removed. A 2018 review of the evidence reports that European Neuroendocrine Tumor Society guidelines recommend a wait-and-see approach for tumors under 2 cm. Watching means imaging every 6 months at first and yearly after that. Tumors 2 cm or larger and hormone-producing tumors are generally removed. Across the studies in that review, about 14% of people under surveillance went on to surgery over a median follow-up of 28 to 45 months.
Surgery is the treatment that can cure a pNET confined to the pancreas. The operation depends on where the tumor sits. A tumor in the head of the pancreas usually needs a pancreatoduodenectomy, known as the Whipple procedure. A tumor in the tail is removed with a distal pancreatectomy, sometimes along with the spleen.
When a pNET has spread or can’t be fully removed, the aim shifts to controlling its growth and its symptoms. Options include:
- somatostatin analogs such as octreotide or lanreotide, which can slow tumor growth and hormone release
- targeted drugs, including everolimus, sunitinib and cabozantinib
- peptide receptor radionuclide therapy (PRRT) with lutetium Lu 177 dotatate, for tumors that show up on the receptor PET scan
- chemotherapy
- liver-directed treatments such as ablation or embolization
The order depends on the tumor’s grade, its hormone activity, how far it has spread and the symptoms it causes. Because pNETs are uncommon, having the plan reviewed at a center that treats many pancreatic tumors can widen the options on the table.
What the survival numbers can and cannot tell you
The American Cancer Society reports these five-year relative survival rates for people diagnosed with a pNET between 2015 and 2021, drawn from the national SEER cancer registry:
| Stage at diagnosis | 5-year relative survival |
|---|---|
| Localized (within the pancreas) | 91% |
| Regional (nearby tissue or lymph nodes) | 64% |
| Distant (liver, lungs or bone) | 19% |
| All stages combined | 48% |
Source: American Cancer Society, pNET survival rates
These figures compare people with pNETs to people in the general population. They reflect stage at diagnosis only, not what happens after treatment. The distant-stage figure of 19% groups slow-growing grade 1 tumors with fast-growing ones, and tumor grade and response to treatment both shift an individual’s outlook. People diagnosed today may do better than the table shows, because the data come from people treated at least five years earlier. The numbers describe large groups and cannot predict any one person’s course.
Take these questions to a NET specialist
Your first specialist visit goes further when you bring copies of every report, so you can match the details above to your own.
- Is my tumor a well-differentiated NET or a neuroendocrine carcinoma?
- What are the grade and the Ki-67 index?
- Does it make a hormone, and which blood tests checked for that?
- Did the tumor show up on a receptor PET scan, or is one planned?
- With this size, location and grade, is surveillance an option, or which operation do you recommend?
- Should I have germline genetic testing, and should my relatives?
- Has a tumor board with neuroendocrine experience reviewed my case?
Call the specialist’s office before your next scheduled scan if new symptoms appear while you wait, such as low blood sugar spells, ulcers that return or diarrhea that won’t settle.
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About this content
How this article was put together: researched from recognised health sources, drafted with the help of AI tools, and edited by hand, with sources linked throughout.
Dr. Pooja Sahu, MBBS, is a medical reviewer for MyMedicineAdvisor. She is a clinical physician whose experience includes serving as a Junior Resident in Nephrology at Dr. Ram…
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The content on My Medicine Advisor is provided for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Health information on this website should not be used to diagnose, treat, cure, or prevent any condition without guidance from a qualified healthcare professional. Always seek the advice of your doctor, physician, or another licensed healthcare provider with any questions you may have regarding a medical condition, symptoms, medications, or treatment decisions.
