Actor Irrfan Khan can justifiably consider himself distinctly unlucky as the incidence of the neuroendocrine tumour is 5-6 per lakh people. Not only are these tumours extremely rare, they also arise from very special cells that are prevalent across the nervous system, especially in parts that serve the lungs, intestinal tracts and other organs.
These are very specialised, chemo-receptor kind of neuro cells, which enable the brain to monitor metabolic or chemical activities in the body. Known earlier as APUD (Amine Precursor Uptake Dehydrogenase Cells), the ‘carcinoid’ tumour cells are rare. However, owing to higher levels of awareness and advanced investigations, these tumours are now being increasingly detected.
The most common site for these tumours is the intestinal tract, starting from the small intestine and the appendix to the large bowel followed by the lungs – bronchial. Very rarely do these tumours occur in the pancreas, pelvic, ovary and uterine?. Most of these tumours are benign, but a small percentage of them can be aggressive and behave like malignant cancers. They can metastasise and spread to other parts of the body and be life-threatening.
However, due to better investigations, more and more tumours, even if they are very small, are being detected. These tumours, because of their specialised cells, not only produce mechanical symptoms, but they also cause chemical imbalances and abnormal metabolites in the body, which sometimes help in the diagnosis process.
Definitive diagnosis, however, still requires a biopsy. Once diagnosed, regardless of its location, it is easier and better to remove a tumour. If a tumour is suspected to be in the lungs, it is at times difficult to do a biopsy and we might have to use a test called the bronchoscopy to carry it out. Among the treatment modes available are chemotherapy, which needs to be administered in combination with radiation therapy in the case of metastatic tumours and large, if it is a single tumour, its removal leads to the best outcomes. If a tumour is benign, the five-year survival goal can be achieved in 45-90 per cent of the cases (depending on the location of a tumour). On the other hand, if a tumour is malignant this can drop to around 30-40 per cent.
Similar tumours in the blood vessels are called the carotid body tumour. Found in the carotid body in the carotid arteries, these are usually pressure and chemosensitive cells. The carotid body keeps the brain informed about blood pressure and also the character of the oxygenation of the blood. Such a tumour can cause a sudden fluctuation in the blood pressure. For example, a mere rub on the neck may send the blood pressure soaring and cause the patient to fall down, leading to brain haemorrhage and even a stroke. These types of tumours can be operated upon and removed completely. It will stop both the mechanical effects and the chemical disturbances.
Neuroendocrine tumours can occur in people of all ages, across all races and both sexes though women are at a slightly greater risk. Chemotherapy produces very good results; but in the case of a metastatic tumour, it needs to be combined with radiotherapy. All these tumour cases need continuous follow up for many years to ensure there is no relapse, recurrence or spread.
The author is Founder & Chief Neurosurgeon, Brains Neuro Spine Centre