Allison, WA
- Small Bowel
This experience has made me a firm believer in screening, early diagnosis, and specialist NET care. I feel incredibly lucky — and grateful — that my NET was found at such an early, treatable stage.
Duodenal Neuroendocrine Cancer
What is duodenal neuroendocrine cancer?
Duodenal neuroendocrine cancer, also known as duodenal neuroendocrine tumours (dNETs), is a rare cancer that develops in the duodenum, the first part of the small intestine. These tumours arise from neuroendocrine cells, which produce hormones that regulate digestion and other bodily functions.
Duodenal NETs are part of the broader group of gastroenteropancreatic neuroendocrine tumours (GEP-NETs). They account for a small proportion of digestive tract tumours, but their detection is increasing due to improved imaging and endoscopic techniques.
These tumours can be:
- Functioning, meaning they produce excess hormones and cause specific symptoms
- Non-functioning, meaning they do not produce hormones and may remain silent
Duodenal NETs originate in hormone-producing cells and may or may not cause hormone-related syndromes.
Key characteristics of duodenal NETs
Location and development
Most DNETs are located in the first or second part of the duodenum, with only 20% occurring in the periampullary area. They may also arise near the ampulla or within the intestinal lining.
Growth behaviour
Many are well-differentiated and slow-growing, although some, particularly high-grade tumours, can behave more aggressively.
Functional status
Most, (Up to 90%) are non-functioning. Functional tumours may produce hormones like gastrin or somatostatin.
Incidence
Incidences are rare overall but are being diagnosed more frequently due to routine endoscopy and imaging.
Types and subtypes of duodenal neuroendocrine tumours
Duodenal NETs are classified based on differentiation and hormone production.
By differentiation
Neuroendocrine tumours (NETs)
- Well-differentiated
- Slower growing
- Better prognosis
Neuroendocrine carcinomas (NECs)
- Poorly differentiated
- Fast growing and aggressive
- Require intensive treatment
By hormone production
Gastrinoma
- Produces gastrin
- Causes Zollinger–Ellison syndrome
- Leads to severe ulcers and reflux
Somatostatinoma
- Produces somatostatin
- May cause diabetes, jaundice, and digestive issues
Non-functioning tumours
- Most common
- Do not produce noticeable hormone symptoms
Symptoms of duodenal neuroendocrine cancer
Many duodenal NETs are asymptomatic and found incidentally. When symptoms do occur, they may be vague and easily mistaken for other conditions.
Common symptoms
- Abdominal pain or discomfort
- Nausea and vomiting
- Bloating
- Unexplained weight loss
- Fatigue
Hormone-related symptoms
If the tumour is functioning:
- Flushing
- Chronic diarrhoea
- Heartburn or acid reflux
Complications
- Gastrointestinal bleeding (black or bloody stools)
- Anaemia due to slow bleeding
- Jaundice may occur if the bile ducts become affected or obstructed
As reflected in the original content, symptoms may include abdominal pain, fatigue from anaemia, and hormone-related effects .
How duodenal neuroendocrine cancer is diagnosed
Diagnosis typically involves multiple steps to confirm the tumour and assess its spread.
Endoscopy (gold standard)
- Upper endoscopy (EGD) allows direct visualisation
- Biopsy confirms diagnosis
Endoscopic ultrasound (EUS)
- Determines tumour depth
- Assesses nearby lymph nodes
Imaging
- CT scan or MRI to evaluate spread
- PET scans (especially Ga-68 DOTATATE) to detect NET activity
Blood and urine tests
- Chromogranin A
- Hormone-specific markers
- 5-HIAA urine test if carcinoid syndrome is suspected
Grading of duodenal NETs (Ki-67 index)
Grading measures how quickly the tumour is growing.
| Grade | Ki-67 index | Behaviour |
| G1 (low grade) | <3% | Slow growing |
| G2 (intermediate) | 3–20% | Moderate growth |
| G3 (high grade) | >20% | Fast growing |
- G1 and G2 tumours are usually well-differentiated
- G3 tumours may be aggressive neuroendocrine carcinomas
Grading is one of the most important factors in determining treatment.
Treatment options for duodenal neuroendocrine cancer
Treatment depends on tumour size, grade, and whether the cancer has spread.
Endoscopic treatment (small tumours)
- Used for tumours typically less than 5mm
- Includes endoscopic mucosal resection (EMR)
- May be followed by surveillance
Surgery (larger tumours)
- Recommended for tumours larger than 10mm
- Tumour has spread to the submucosal layer, the supportive layer just beneath the inner lining of the bowel, and/or to the lymph nodes.
- Tumour grade 2 or 3
- Functioning tumour
- Options include:
- Local resection
- Pancreaticoduodenectomy (Whipple procedure)
Medical therapies (advanced disease)
Somatostatin analogues (SSAs)
- Control hormone symptoms
- Slow tumour growth
Peptide receptor radionuclide therapy (PRRT)
- Targeted radiation therapy
- Used in metastatic or progressive disease
Chemotherapy
- Typically for high-grade or aggressive tumours
Targeted therapies
- May be used in selected cases
Prognosis and survival
Prognosis varies depending on duodenal neuroendocrine tumour characteristics.
Favourable factors
- Small tumour size
- Low grade (G1)
- No metastasis
Survival rates
- Well-differentiated tumours: approximately 80–85% 5-year survival
- Poorly differentiated tumours: lower survival due to aggressive behaviour
As will all kinds of cancer, early detection significantly improves outcomes.
Genetic and hereditary factors
Most duodenal NETs are sporadic, but a minority are linked to inherited conditions.
Key syndromes
- Multiple Endocrine Neoplasia Type 1 (MEN1)
- Neurofibromatosis Type 1 (NF1)
- Zollinger–Ellison syndrome (linked to gastrinomas)
Patients with the following may benefit from genetic testing and specialist evaluation:
- Multiple tumours
- Family history of endocrine disease
Nutrition and lifestyle considerations
Diet and lifestyle can play an important role in managing symptoms, particularly in tumours that produce serotonin.
Dietary strategies
- Eat small, frequent meals
- Avoid trigger foods such as alcohol, spicy foods, and high-amine foods
- Maintain hydration
Nutritional risks
- Malabsorption in some cases
- Risk of niacin (vitamin B3) deficiency
Scheduling am appointment with a specialist dietitian from NECA can help tailor nutrition plans for patients at all treatment stages of neuroendocrine duodenal cancer.
Emerging treatments and research
Treatment for neuroendocrine cancers is evolving rapidly.
New developments
- Targeted therapies such as kinase inhibitors
- Next-generation radioligand therapies
Clinical trials
Patients with advanced disease may benefit from:
- Access to new therapies
- Personalised treatment approaches
Specialist care and support
Because duodenal NETs are rare, specialist care is critical. When treating duodenal NETs, your multidisciplinary care team may include:
- Gastroenterologists
- Oncologists
- Surgeons
- Nuclear medicine specialists
Frequently asked questions about duodenal neuroendocrine cancer
It is a rare cancer that forms in hormone-producing cells in the duodenum, part of the small intestine.
Yes. Many are slow-growing and less aggressive, but some can behave more aggressively depending on grade.
Non-functioning tumours are the most common, making up the majority of cases.
Small tumours may be removed endoscopically, while larger or advanced tumours may require surgery or systemic therapies.
Well-differentiated tumours have a high survival rate, often around 80–85% at five years.
Yes. Due to their rarity and complexity, treatment by a NET specialist team is strongly recommended.
If you’ve been diagnosed with duodenal neuroendocrine cancer, early specialist care and access to support services can significantly improve both outcomes and quality of life.
When to seek medical advice
You should speak to a doctor if you experience:
- Persistent abdominal pain
- Unexplained weight loss
- Chronic diarrhoea
- Ongoing fatigue or anaemia
- Gastrointestinal bleeding
Early investigation, beginning with a GP appointment, can lead to earlier diagnosis and better outcomes.
Next steps
If you’ve been diagnosed with a duodenal NET, or know someone who has been diagnosed, here are some next steps to take.
- Confirm tumour stage and pathology findings
- Understand whether further treatment is needed
- Discuss follow-up with a specialist
For guidance and support, contact the NECA NET Nurse.
Patient Stories
Bob, NSW
- Small Bowel
Having a family history of cancer, both mother and father, my own diagnosis of NETs probably shouldn’t have taken me by surprise but it did.
Brad, VIC
- Small Bowel
I went and got the diagnosis alone. Probably not a good idea. You hear the first words, ‘You’ve got cancer’ and then you don’t hear another word after that.
Bronwyn, NSW
- Small Bowel
I encourage everyone to share their story—on the NeuroEndocrine Cancer Australia website and within their own communities—so that NETs is recognised and diagnosed earlier. I also encourage fundraising for NeuroEndocrine Cancer Australia if possible.
Chris, WA
- Small Bowel
I have worked in healthcare my entire life I had never heard of NETs until my diagnosis and I’m pretty sure none of the doctors I had seen in the lead up to diagnosis knew about it either.
Denae, SA
- Small Bowel
The NECA NET Nurse gave me so much support and information. The phone support wasn’t rushed like medical appointments, the resources that she emailed me were full of useful information that I could share with my family. I feel better equipped to advocate for myself now. I don’t feel so alone anymore.
Denise, NSW
- Small Bowel
When the histopathology returned six days post-surgery, everything made sense. A slow-growing cancer: Carcinoid, or Neuroendocrine Tumour, a term only just coming into use at that time. My feelings? Overwhelmingly, relief. Validated after two and a half years of being dismissed. Some anger, too, but mostly relief to finally have a diagnosis I could understand and act on.
Denise, TAS
- Small Bowel
The specialist NECA NET Nurse was not only a sympathetic ear, but she was also practical and very efficient. Within weeks, she had secured me an appointment at Peter Mac, with Associate Professor Michael Michael, and for the first time in the many months since diagnosis, I felt heard, safe, and confident that my treatment was in the right hands.
Doreen, WA
- Small Bowel
Through attending NET meetings at FSH I was made more aware of NETS and found friendship and understanding from all who attended plus I had found a ‘home’ where others understood.
Greg, QLD
- Small Bowel
Greg’s symptoms included tiredness, fatigue and diarrhoea.
Helpful Resources
Fact Sheets
5HIAA
Causes & Risk Factors
Abdominal Pain in NETs
Booklets & Guides
About NETs
Booklets & Guides
Acronyms & Terminology for Neuroendocrine Cancer Patients
Causes & Risk Factors
Age and Gender as Risk Factors for NETs
Treatment Options
Anatomic Distribution of Neuroendocrine Tumours
Booklets & Guides
Associated Conditions
Clinical Trials
AUS-NET – Neuroendocrine Tumours
To improve patient quality of life and develop a cost-effective system that can be implemented across other rare cancers in the future.
Other Resources
Australian Patient Travel Subsidy Scheme
Booklets & Guides
