Neuroendocrine tumours (NETs) arise from neuroendocrine cells, which have the unique ability to produce and secrete hormones. These tumours can develop in various parts of the body, including the pancreas, gastrointestinal tract, and lungs.
Due to their ability to secrete hormones, NETs can significantly impact the body’s metabolism, including the regulation of blood sugar levels.
Neuroendocrine Cancer Australia (NECA), is dedicated to assisting individuals with neuroendocrine cancer and their families. NECA offers a wealth of resources, educational programs, and advocacy efforts aimed at deepening the understanding of NETs, improving patient care, and encouraging research advancements. Patients diagnosed with NETs can engage with NECA’s comprehensive support and information by calling the NET nurse line.
The hormones produced by NETs can have profound effects on the body’s metabolic processes, particularly blood glucose regulation.
Hormones like insulin, glucagon, and other peptides play crucial roles in maintaining normal blood glucose levels.
When NETs secrete these hormones in excess or when their production is dysregulated, it can lead to significant imbalances in blood glucose levels, contributing to:
We’ll investigate these impacts a bit further down under symptoms.
There are several causes of blood glucose imbalances in NET patients depending on the kind of tumour.
Insulinomas are a type of NET that originates from the insulin-producing cells of the pancreas. These tumours secrete excess insulin, which can cause blood glucose levels to drop dangerously low, leading to hypoglycemia.
Although insulinomas are relatively rare, accounting for about 4% of all NETs, their impact on blood glucose regulation can be profound and requires careful management.
Glucagonomas are another type of NET that affects blood sugar levels, but in the opposite direction. These tumours arise from the cells that produce glucagon, a hormone that raises blood glucose levels by stimulating the liver to release stored glucose into the bloodstream.
Glucagonomas are even more rare than insulinomas, making up less than 1% of NETs. However, they can significantly impact a patient’s quality of life by causing diabetes-like symptoms.
Other NETs, such as somatostatinomas or gastrinomas, can also influence blood sugar levels indirectly.
For instance, somatostatinomas can inhibit the secretion of insulin, leading to hyperglycemia.
The treatment of NETs can also have significant effects on blood glucose levels. Surgical removal of the tumour, for instance, can lead to fluctuations in hormone levels, potentially causing hypoglycemia or hyperglycemia as the body adjusts.
When a patient undergoes a pancreatectomy, depending on how much of the pancreas is removed it can result in minimal to no beta cells (insulin) or alpha cells (glucagon) left. This means the person needs to be treated with insulin for the rest of their life.
This is further complicated when the person experiences a hypoglycaemia episode, their pancreas cannot produce glucagon to resolve, increasing their risk for severe hypoglycaemia.
Additionally, treatments like chemotherapy, targeted therapy, or peptide receptor radionuclide therapy (PRRT) can impact the pancreas and other organs involved in glucose regulation, leading to further challenges in managing blood glucose levels.
NET patients should keep an eye out for a range of blood glucose related symptoms.
Hypoglycemia is a common and potentially dangerous condition for NET patients, particularly those with insulinomas.
Symptoms of hypoglycemia include:
And if untreated:
Patients with NETs that cause hypoglycemia must be vigilant in monitoring their blood glucose levels and managing their symptoms promptly.
Hyperglycemia, on the other hand, is typically seen in patients with glucagonomas or other NETs that disrupt normal insulin function.
Common symptoms include:
Persistent hyperglycemia can lead to long-term complications such as diabetic peripheral neuropathy, kidney damage, and cardiovascular disease, making it crucial for NET patients to manage their blood glucose levels effectively.
NET patients may also experience episodes of blood glucose fluctuations, where they swing between hypoglycemia and hyperglycemia.
These fluctuations can be particularly challenging to manage, as they require constant monitoring and adjustment of treatment plans.
Long-term complications of blood glucose imbalances in NET patients can be severe.
Chronic hyperglycemia can lead to:
One or several of these symptoms and conditions described above can be an indication of blood glucose levels being affected by NETs. Diagnosis and monitoring gives patients the best possible chance at managing the disease.
Here’s are some steps a patient might follow below:
Regular blood glucose testing is essential for diagnosing and monitoring blood glucose imbalances in NET patients. This includes measuring fasting glucose levels and HbA1c, a marker that reflects average blood glucose levels over the past three months.
For patients with insulinomas, frequent blood glucose testing is crucial to detect hypoglycemia early and prevent severe episodes.
Continuous Glucose Monitoring (CGM) is an advanced method that allows for real-time tracking of blood sugar levels. CGM devices are particularly useful for NET patients who experience frequent or unpredictable blood sugar fluctuations.
These devices provide continuous data, helping patients and their healthcare providers make informed decisions about diet, medication, and lifestyle adjustments.
Hormonal assays that measure levels of insulin and glucagon can provide valuable insights into the underlying causes of blood glucose imbalances in NET patients.
For instance, elevated insulin levels may indicate an insulinoma, while high glucagon levels could suggest a glucagonoma.
Imaging studies, such as MRI, CT scans, and functional tests like the Octreotide scan, are crucial in diagnosing NETs and assessing their impact on blood glucose regulation.
These tests help identify the location, size, and activity of the tumour, guiding treatment decisions and monitoring the effectiveness of interventions.
Fortunately, there are ways that NET patients can monitor and manage their blood glucose levels. This management can lead to better ongoing outcomes as the disease is treated.
Medical management of blood glucose levels in NET patients often involves a combination of medications and hormone therapies tailored to the specific needs of the patient.
Diet and lifestyle play a critical role in managing blood glucose levels in NET patients. Working with a nutritionist or dietitian can help patients develop meal plans that stabilise blood glucose levels and meet their nutritional needs.
Patients should work with their healthcare team to develop a safe diet or exercise routine that supports overall health without compromising blood glucosecontrol.
Surgery is often a key treatment for NETs that cause significant blood glucose imbalances.
Like any condition that affects blood glucose levels, NETs can have a significant impact on a patient’s quality of life. Constant monitoring of blood glucose levels can help patients feel relatively normalised as treatment progresses.
Managing blood glucose levels is a daily challenge for many NET patients, requiring constant vigilance and adjustments to diet, medication, and lifestyle. This ongoing need for monitoring and management can be stressful and time-consuming.
Coping with episodes of hypoglycemia and hyperglycemia can be both physically and emotionally taxing. Patients must be prepared to manage symptoms quickly and effectively, which can cause anxiety and fear, particularly if episodes occur frequently or unpredictably.
The emotional and psychological toll of living with blood glucose imbalances due to NETs cannot be underestimated. Anxiety about managing symptoms, fear of complications, and the stress of ongoing medical care can all contribute to emotional distress.
Further information and support for people diagnosed with NETs is available by calling the NECA NET nurse line.
