Neuroendocrine tumours are rare cancers that develop in specialised cells combining features of nerve cells and hormone-producing cells, most commonly appearing in the digestive system, lungs, and pancreas. The approach to managing these complex tumours depends heavily on their location, growth speed, hormone activity, and how far they have spread throughout the body.

How Treatment Decisions Are Made for Neuroendocrine Tumours

When someone receives a diagnosis of a neuroendocrine tumour, often abbreviated as NET, the journey ahead involves careful planning tailored to their unique situation. These tumours behave very differently from person to person, which means treatment cannot follow a single standard path. The primary goals of treatment focus on controlling symptoms, slowing or stopping tumour growth, improving quality of life, and when possible, removing the cancer entirely^[1].

Medical teams consider several important factors when developing a treatment plan. The tumour’s location matters enormously—whether it sits in the stomach, intestines, pancreas, lungs, or elsewhere determines which treatment approaches will work best. The size of the tumour and whether it has spread to other organs also shapes decisions. Additionally, doctors assess whether the tumour produces excess hormones, a characteristic that can cause specific symptoms requiring targeted management^[2].

Another crucial element is the grade of the tumour, which indicates how quickly the cells are dividing. Low-grade tumours grow slowly, while high-grade ones multiply rapidly. The stage describes how far the disease has progressed—whether it remains in one spot or has travelled to distant parts of the body. These classifications, determined through careful examination of tissue samples and imaging studies, guide the entire treatment strategy^[6].

Medical societies worldwide have published guidelines to help doctors make evidence-based treatment decisions. However, because neuroendocrine tumours are so varied and relatively uncommon, care is ideally delivered by a multidisciplinary team. This team typically includes surgeons, medical oncologists specialising in cancer treatment, radiologists who interpret scans, nuclear medicine specialists, and nurses with expertise in neuroendocrine cancers. Working together, they can address the complexity these tumours present^[16].

Standard Treatment Approaches

Surgery as the Primary Treatment

Surgery remains the cornerstone of treatment for many people with neuroendocrine tumours, particularly when the disease is detected early. The goal is typically to remove the tumour completely, along with any affected lymph nodes nearby. When surgeons can remove all visible cancer, this offers the best chance of cure. Even in advanced cases where the cancer has spread, surgery may still play a role—either to reduce the tumour’s size to alleviate symptoms or to remove tumours causing problems in specific organs^[13].

The type of surgery depends entirely on where the tumour is located. For tumours in the digestive tract, surgeons may remove portions of the intestine, stomach, or other affected structures. Pancreatic neuroendocrine tumours might require removal of part or all of the pancreas. In cases where tumours have spread to the liver—a common occurrence with these cancers—specialised techniques can remove or destroy liver metastases. Some centres offer extensive liver surgery called debulking, where surgeons remove as much tumour tissue as possible even when complete removal isn’t feasible^[14].

Minimally invasive surgical techniques, including robotic and laparoscopic surgery, are increasingly used when appropriate. These approaches involve smaller incisions, potentially leading to faster recovery and fewer complications. However, the complexity of the surgery depends on the tumour’s size, location, and relationship to surrounding blood vessels and organs. Not everyone is a candidate for surgery, particularly if the disease is too widespread or if other health conditions make surgery too risky^[15].

Somatostatin Analogues for Hormone Control

Many neuroendocrine tumours produce hormones that cause troublesome symptoms. When tumours make excessive amounts of hormones like serotonin, patients may experience flushing of the skin, severe diarrhoea, abdominal cramping, and other problems collectively known as carcinoid syndrome. To manage these symptoms, doctors often prescribe medications called somatostatin analogues^[13].

These medicines work by mimicking a natural hormone in the body called somatostatin, which regulates the release of other hormones. The two main somatostatin analogues used are octreotide and lanreotide. Patients typically receive these medications as monthly injections. Beyond controlling hormone-related symptoms, research has shown that somatostatin analogues can also slow tumour growth in certain types of neuroendocrine tumours, particularly those that are low to intermediate grade^[14].

These medications are generally well tolerated, with side effects usually mild. Some people experience digestive upset, including nausea, abdominal discomfort, or changes in bowel habits. Long-term use can sometimes lead to gallstones. Despite potential side effects, many patients remain on these treatments for years, maintaining good symptom control and stable disease^[16].

Chemotherapy

Chemotherapy uses powerful drugs to kill rapidly dividing cancer cells throughout the body. While chemotherapy is less commonly the first choice for slow-growing neuroendocrine tumours, it plays an important role for certain tumour types and situations. High-grade, rapidly growing neuroendocrine tumours often require chemotherapy as a primary treatment. Additionally, pancreatic neuroendocrine tumours may respond well to specific chemotherapy regimens^[13].

Several chemotherapy drugs have shown effectiveness against neuroendocrine tumours. Combinations might include temozolomide with capecitabine, or regimens using streptozocin combined with 5-fluorouracil. For more aggressive neuroendocrine carcinomas, doctors may use platinum-based chemotherapy similar to that used for small cell lung cancer. The choice of chemotherapy depends on the tumour’s grade, location, and prior treatments^[14].

Chemotherapy carries more significant side effects than some other treatments for neuroendocrine tumours. Common problems include fatigue, nausea and vomiting, hair loss, decreased blood cell counts leading to infection risk or anaemia, and numbness or tingling in the hands and feet. The severity and type of side effects vary depending on which drugs are used. Medical teams work to manage these effects with supportive medications and adjustments to treatment schedules when needed^[16].

Targeted Therapies

Targeted therapies represent a more modern approach to cancer treatment. Unlike chemotherapy, which attacks all rapidly dividing cells, targeted drugs aim at specific molecules involved in tumour growth. For neuroendocrine tumours, two targeted drugs have become important treatment options: everolimus and sunitinib^[11].

Everolimus works by blocking a protein called mTOR, which helps regulate cell growth and division. When mTOR is blocked, cancer cells receive signals to stop growing and dividing. This drug has shown effectiveness in both pancreatic neuroendocrine tumours and those originating in the gastrointestinal tract. Sunitinib targets different proteins called receptor tyrosine kinases that promote blood vessel formation to feed tumours. By blocking these proteins, sunitinib can starve tumours of their blood supply. It is primarily used for pancreatic neuroendocrine tumours^[16].

These medications are taken as pills, making them more convenient than intravenous treatments. However, they do cause side effects. Everolimus commonly causes mouth sores, infections, high blood sugar, and lung inflammation. Sunitinib may lead to fatigue, high blood pressure, skin colour changes, and digestive problems. Regular blood tests monitor for complications, and dose adjustments help manage tolerability while maintaining effectiveness.

Liver-Directed Therapies

Because neuroendocrine tumours often spread to the liver, several specialised treatments target liver metastases specifically. These procedures, performed by interventional radiologists, deliver treatment directly to liver tumours while sparing healthy liver tissue as much as possible^[15].

One approach is trans-arterial embolisation, or TAE, which involves blocking the blood vessels feeding liver tumours. The radiologist threads a thin tube called a catheter through arteries to reach the vessels supplying the tumours, then injects materials that block these vessels. Since tumours depend heavily on blood flow, cutting off their supply causes them to shrink or stop growing. A related technique, trans-arterial chemoembolisation (TACE), combines blocking the blood supply with delivering chemotherapy directly to the tumour^[13].

Other liver-directed options include radiofrequency ablation and microwave ablation. These treatments use heat—generated by radio waves or microwaves—to destroy tumour tissue. A probe is inserted directly into the tumour, usually guided by imaging, and heat is applied to kill cancer cells. These techniques work best for smaller tumours or a limited number of liver metastases. They may be repeated if new tumours appear^[13].

Innovative Treatments in Clinical Trials

Peptide Receptor Radionuclide Therapy (PRRT)

One of the most significant advances in treating neuroendocrine tumours is peptide receptor radionuclide therapy, known as PRRT. This treatment combines two elements: a targeting molecule that finds neuroendocrine tumour cells and a radioactive particle that destroys them. Many neuroendocrine tumours have receptors on their surface for somatostatin. PRRT takes advantage of this by attaching a radioactive substance to a somatostatin-like molecule. When injected into the bloodstream, this combination travels through the body and binds specifically to tumour cells, delivering radiation directly to the cancer^[8].

The most commonly used PRRT agent is called lutetium-177 dotatate. Treatment typically involves four doses given about eight weeks apart. Patients receive the medication through an intravenous infusion that takes several hours. Because the radiation is delivered precisely to tumour cells, PRRT causes fewer side effects than traditional external beam radiation. Clinical trials have demonstrated that PRRT can significantly slow disease progression and improve quality of life in patients with advanced neuroendocrine tumours that express somatostatin receptors^[14].

Not everyone is a candidate for PRRT. Before treatment, patients undergo a special imaging scan called a somatostatin receptor PET scan or dotatate PET scan to confirm that their tumours have enough receptors to make the treatment effective. Side effects of PRRT are generally mild and may include fatigue, nausea, and temporary changes in blood cell counts. A small percentage of patients may experience kidney or bone marrow problems, requiring careful monitoring. Despite being relatively new, PRRT has become an important option at specialised centres for patients with progressive disease^[16].

Immunotherapy

Immunotherapy represents an exciting frontier in cancer treatment. These drugs work by helping the patient’s own immune system recognise and attack cancer cells. While immunotherapy has revolutionised treatment for several cancer types, its role in neuroendocrine tumours is still being explored in clinical trials^[16].

The main types of immunotherapy being studied for neuroendocrine tumours are checkpoint inhibitors. These drugs block proteins that prevent immune cells from attacking cancer. By releasing these brakes on the immune system, checkpoint inhibitors can unleash a powerful anti-tumour response. Drugs like pembrolizumab and nivolumab, which target a protein called PD-1, are being tested in various clinical trials for neuroendocrine cancers.

Early research suggests that immunotherapy may be most effective in high-grade neuroendocrine carcinomas or in tumours with specific genetic characteristics called high microsatellite instability or high tumour mutational burden. These genetic features make tumours more visible to the immune system. Clinical trials are ongoing at major cancer centres in the United States, Europe, and other regions to better understand which patients will benefit most from immunotherapy. Because this is still an emerging area, immunotherapy for neuroendocrine tumours is primarily available through clinical trial participation^[11].

Novel Targeted Agents

Researchers continue developing new drugs that target specific molecular pathways involved in neuroendocrine tumour growth. Several promising agents are currently in various phases of clinical testing. These trials help determine whether new drugs are safe (Phase I), whether they work against the cancer (Phase II), and how they compare to existing treatments (Phase III)^[16].

One area of active investigation involves drugs that target the blood vessels feeding tumours, similar to sunitinib but with different mechanisms or improved tolerability. Another research direction focuses on drugs that interfere with DNA repair mechanisms in cancer cells. For example, drugs called PARP inhibitors, which have shown success in other cancer types, are being studied in neuroendocrine tumours, particularly those with certain genetic mutations.

Some trials are exploring combination approaches, using two or more drugs together to attack tumours through multiple pathways simultaneously. For instance, combining targeted therapy with immunotherapy or combining different types of targeted drugs may prove more effective than single-agent treatment. These studies often recruit patients whose disease has progressed despite standard treatments, offering access to cutting-edge therapies that wouldn’t otherwise be available^[14].

Gene Therapy and Viral Therapies

Emerging research is investigating even more innovative approaches. Oncolytic virus therapy uses specially engineered viruses that can infect and kill cancer cells while leaving normal cells unharmed. These viruses also stimulate an immune response against the tumour. While still highly experimental for neuroendocrine tumours, some clinical trials are beginning to test these approaches.

Gene therapy techniques aim to modify cells—either the patient’s own immune cells or the cancer cells themselves—to fight the disease. For example, researchers are exploring ways to enhance immune cells’ ability to recognise neuroendocrine tumour cells. These highly specialised treatments are available only at major research centres conducting clinical trials. Patients interested in these cutting-edge options should discuss clinical trial opportunities with their oncology team.

Supportive Medications for Symptom Control

Beyond treatments targeting the tumours themselves, research continues on medications that better control symptoms. For patients with carcinoid syndrome experiencing severe diarrhoea despite somatostatin analogues, a relatively new drug called telotristat offers additional help. Telotristat works by blocking the production of serotonin, the hormone that causes many carcinoid syndrome symptoms. Taken as pills three times daily, it can significantly reduce bowel movements and improve quality of life^[16].

Clinical trials are also investigating better ways to manage other complications of neuroendocrine tumours, such as nutritional deficiencies, bone health problems, and cardiovascular issues that can result from long-term hormone excess. Research into optimal supportive care helps patients maintain better health and wellbeing throughout their treatment journey.

Most Common Treatment Methods

• Surgery
  • Removal of tumours and affected lymph nodes, offering the best chance of cure when disease is localised
  • Debulking surgery to reduce tumour burden even when complete removal isn’t possible
  • Liver surgery including resection and transplantation for metastatic disease
  • Minimally invasive and robotic surgical techniques when appropriate
• Hormone-Targeted Therapy
  • Somatostatin analogues (octreotide, lanreotide) for symptom control and tumour growth inhibition
  • Telotristat for managing carcinoid syndrome diarrhoea
  • Monthly injections maintaining long-term symptom control
• Molecular Targeted Drugs
  • Everolimus blocking mTOR pathway to slow tumour growth
  • Sunitinib targeting blood vessel formation in pancreatic NETs
  • Oral medications taken daily at home
• Liver-Directed Treatments
  • Trans-arterial embolisation blocking blood supply to liver tumours
  • Radiofrequency and microwave ablation destroying tumours with heat
  • Chemoembolisation combining vessel blockage with chemotherapy delivery
• Peptide Receptor Radionuclide Therapy (PRRT)
  • Lutetium-177 dotatate delivering targeted radiation to tumour cells
  • Four treatments given over approximately six months
  • Available at specialised centres for advanced disease
• Chemotherapy
  • Temozolomide and capecitabine combinations for pancreatic NETs
  • Platinum-based regimens for high-grade neuroendocrine carcinomas
  • Streptozocin-based treatments for specific tumour types
• Immunotherapy (in clinical trials)
  • Checkpoint inhibitors like pembrolizumab and nivolumab
  • Being studied particularly for high-grade tumours
  • Available primarily through clinical trial participation
• External Beam Radiation
  • Stereotactic radiation for specific metastases, particularly in brain or bone
  • Palliative radiation to control pain from bone metastases
  • Less commonly used than in other cancer types but valuable in specific situations

Living With Neuroendocrine Tumours During Treatment

Managing a neuroendocrine tumour involves more than medical treatments. Because many patients live with their disease for years, even decades, quality of life becomes paramount. Many people continue working, maintaining relationships, travelling, and pursuing hobbies throughout their treatment^[17].

Diet plays an important role, especially for patients with carcinoid syndrome. Certain foods and drinks can trigger symptoms like flushing and diarrhoea. These include aged cheeses, red wine, chocolate, smoked meats, and fermented foods—all high in compounds called amines that affect body systems. Avoiding these triggers, eating smaller frequent meals, and choosing whole natural foods over processed options can help manage symptoms. Some patients work with dietitians specialising in neuroendocrine tumours to develop personalised eating plans^[20].

Regular exercise, tailored to individual ability and energy levels, helps maintain strength and wellbeing. Even gentle activities like walking for thirty minutes several times weekly can make a difference. Managing stress through meditation, support groups, or counselling helps many people cope with the emotional challenges of living with cancer. Connecting with others who have neuroendocrine tumours, either through in-person groups or online communities, provides valuable support and practical advice^[18].

Regular follow-up with the medical team is essential. This typically includes periodic blood tests to check tumour markers and organ function, along with imaging scans to monitor disease status. How often these tests occur depends on the tumour type, grade, and treatment plan. Patients should communicate openly with their healthcare providers about symptoms, side effects, and any concerns that arise between appointments^[13].