Pancreatic neuroendocrine tumours (pNETs), or islet cell tumours, are rare carcinomas (cancers arising from bone and soft tissuetissue/the material that joins, holds up or surrounds inside body parts such as fat, muscle, ligaments and lining around joints lining the organs) that develop in the pancreasa long, flat organ that sits between the stomach and the spine that plays a key role in digestion and blood sugar regulation. The pancreas has two primary functions; endocrine function, which is responsible for secreting hormones (such as insulin) to control bloodthe red bodily fluid that transports oxygen and other nutrients around the body sugar levels, and exocrine function, which produce pancreatic enzymes that aid in digestion.
Neuroendocrine cancers are a complex group of tumours that develop in the neuroendocrine system, which is responsible for regulating important bodily functions such as heart rate, blood pressure and metabolism. They most commonly develop in the gastro-intestinal tract, pancreas, and the lungs; however, they can develop anywhere in the body. These tumours develop from neuroendocrine cellsthe basic structural and functional unit of all living things, which are responsible for receiving signals from the nervous system and producing hormones and peptides (small proteins) in response.
This page will focus on a specific type of functional pNET called Somatostatinoma, which develops from delta cells in the pancreas. These cells are responsible for the production and secretion of the hormonea chemical substance produced by glands in the endocrine system that regulates various functions in the body somatostatin. Somatostatin, also known as the growth inhibiting hormone, inhibits the secretion of insulin and glucagon to maintain blood sugar (or glucose) levels.
pNETs have a higher incidence in males and are generally diagnosed in people over 55; however, people of any age and sex can develop this disease.
Treatment
If a Somatostatinoma is detected, it will be staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets and how the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumoura tissue mass that forms from groups of unhealthy cells) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissuea group of cells that work together to perform a function.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for somatostainomas may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Tumour resectionsurgical removal of tissue or part/all of an organ.
- Pancreaticoduodenectomyremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a Whipple procedure, also known as a Whipple procedureremoval of part of the pancreas (generally the head), the first part of the small intestine (duodenum), part of the stomach, the gallbladder, and part of the common bile duct; also known as a pancreaticoduodenectomy.
- Total pancreatectomycomplete removal of the pancreas.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells, potentially including peptide receptor radionuclide therapy (PRRT)a targeted cancer treatment that uses radioactive substances (radionuclides) to deliver radiation directly to tumour cells.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
The riskthe possibility that something bad will happen factors for this disease are similar across all types of pNETs. They include:
- Family history of cancer.
- Having conditions such as:
- Type 2 diabetes.
- Multiple endocrine neoplasia type 1 (MEN1).
- Neurofibromatosis type 1 (NF-1).
- Von Hippel-Lindau (VHL) disease.
- Tuberous sclerosis.
- Being a smoker or having a history of smoking.
- Excessive alcohol intake.
- Obesity.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
Unlike non-functional pNETs, functional tumourstumours that produce and secrete hormones such as somatostatinoma may present symptoms in the early stages of the disease. The symptoms of somatostatinoma are caused by excessive somatostatin production, which may lead to the following symptoms:
- Hyperglycaemiahigh blood sugar, which carries its own sets of symptoms:
- Headaches.
- Polyuriafrequent urination.
- Dry skin and/or mouth.
- Sudden hunger and/or thirst.
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Feeling weak.
- Diarrhoeafrequent discharge of watery or loose stools from the body.
- Steatorrheaa condition where there is too much fat in faeces/stool, causing very foul-smelling stool that floats.
- Gallstones.
- Jaundiceyellowing of the skin and the whites of the eyes.
- Unexplained weight loss.
- Anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection.
Not everyone with the symptoms above will have cancer, but see your GP if you are concerned.
Diagnosis
If your doctor suspects you have a somatostatinoma, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Endocrine studiesstudies that involve blood, urine and/or imaging tests to analyse hormone levels.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Exploratory surgeryan exploratory surgical procedure used for conditions that cannot be confirmed by scans and tests alone.
- Biopsyremoval of a section of tissue to analyse for cancer cells.