They are not cancerous by definition, and can be benign.
Bengaluru: Bollywood star Irrfan Khan announced Friday, a week after telling fans he had been diagnosed with a “rare disease”, that he had a neuroendocrine tumour. So, what exactly does it mean? ThePrint spells it out for you.
What are they? Neuroendocrine tumours (NETs) are rare abnormal growths of tissue — such as swelling — in the endocrine and nervous systems. The endocrine system deals with hormones (like testosterone, oxytocin, insulin) and glands that secrete them (like pituitary, thyroid, pancreas).
Are they cancerous? Not until they are diagnosed as “malignant”. Tumours that are benign (non-cancerous) can be operated out safely, for the most part. Sometimes, depending on where they grow or how big they are, a patient might also need chemotherapy or radiation to shrink them either before or after surgery. Use of chemotherapy and radiation does not imply these tumours are cancerous.
Where do they occur? The tumours can occur anywhere in the body. The most common region of occurrence is the intestine, but it can also be the lungs or the pancreas.
How are they detected? Symptoms of NETs are hard to find. Most NETs secrete hormones just like glands. Changes in the body resulting from excess hormone production are the only way to suspect they exist. This is doubly challenging because, firstly, such symptoms can be common. For example, an excess production of a hormone called glucogon results in episodic spikes of blood sugar. High blood sugar is exactly what diabetes, an extremely common disease, is. However, doctors have an informal metric of diagnosis called the index of suspicion. If a 22-year-old goes to a doctor exhibiting symptoms of not only episodic blood sugar spikes, but also high blood pressure and hot flashes, and she was perfectly fine six months ago, a doctor would know something doesn’t add up and maintain her index of suspicion as high.
Secondly, tumours that grow on glands don’t always necessarily secrete the same hormones as the gland. They can be located anywhere in the body, making them hard to find.
How are they confirmed? The most common methods are MRI scans, MIBG scans, blood samples, and biopsies.
Are they fatal? In many cases, they aren’t. Sometimes, they can secrete certain hormones whose overproduction in the body can kill a patient. For example, a tumour producing chronically excess serotonin can lead to heart failure. Their location is also a factor. A pancreatic endocrine tumour almost always has a high probability of fatality. Sometimes, tumours can also be detected very late, making them dangerous. The fatality of these tumours varies widely.
Are the operations risky? This again depends on the location and the size of the tumour. Specialised centres with skilled surgeons often ensure safety.
Are they genetic? Yes, and they can remain hidden for a long time.
Can you survive with them? Yes, several NETs can actually not be detected at all or secrete such low quantities of hormones that they don’t necessarily need to be operated out. If the production of one hormone needs to be combated with another, patients can take supplements and be perfectly healthy.
What are some institutes in India that work on NETs? NET research is conducted at premier institutes like AIIMS, JIPMER Puducherry, CMC Vellore, Apollo Hyderabad, and MIOT Chennai.
Where can I know more? Mayo Clinic has an informative page.