Neuroendocrine tumors are those which arise from the neural cells and hormone-producing cells of the tissue. PNET’s or pancreatic neuroendocrine tumors usually consists of all the tumors related to hormone-producing cells of the pancreas including alpha, beta, gamma, and f cells separately as each individual tumor. The most common of the pancreatic neuroendocrine tumors is beta cell tumor known as insulinoma. Due to the maximum incidence of insulinoma in the neuroendocrine tumors, these are generally referred to as islet cell tumors.
What Causes Pancreatic Neuroendocrine Tumor?
Pancreatic neuroendocrine tumors are of idiopathic origin most of the times. Genetic mutations and hereditary factors are commonly responsible causes for PNET’s. Various syndromic associations have been found with them.
The most commonly and strongly associated cancer syndrome is multiple endocrine neoplasia type 1 also known as a men1 syndrome. Although the most commonly associated PNET with the MEN 1 syndrome is gastrinoma. It is usually associated with other tumors including pituitary and parathyroid glands. Other syndromes related to PNET’s are von Hippel Lindau syndrome, neurofibromatosis type 1, tuberous sclerosis, etc.
Modifiable factors responsible for the pancreatic neuroendocrine tumors are smoking, obesity, diabetes mellitus, drinking alcohol, etc.. History of radiation damage, immunosuppression, and exposure to X-ray, etc. are some of the other factors responsible for these tumors.
Is Pancreatic Neuroendocrine Tumor Curable?
The treatment and curability of these tumors are widely variable and unpredictable. Because this group consists of many types of tumors which vary in their prognosis, it is very difficult to tell that whether they would there be curable or not before the exact diagnosis of the type of pancreatic neuroendocrine tumor is made. If the pancreatic neuroendocrine tumors are detected in early stages of its development or the syndromic association is found in early age then the prophylactic treatment and early resection of the tumors can be done to make them curable.
The prognosis of the pancreatic neuroendocrine tumors also depends upon the site of the tumor in the pancreas. The tumors occurring in the tail region of the pancreas are having a good prognosis because of the success of surgical treatment. The tumors located in the head and neck region of the pancreas have a very poor prognosis because of the less success of the surgical treatment as well as these are located near vital structures. The surgical resection performed in these tumors is very extensive which has high morbidity and mortality rates of itself.
The most common PNET is insulinoma. It has an equal incidence in head body and tail of the pancreas. For the tumors located in the tail region of pancreas the surgical treatment is done is known as distal pancreatectomy which includes the removal of the defective area along with the associated draining lymph nodes. The tumors located in the head region of the pancreas are treated via a surgical procedure known as Whipple’s operation. It includes the removal of the pancreatic head, neck, associated part of duodenum, pylorus, common bile duct, etc.
When the tumor is beyond the resection limit of the surgery or the systemic symptoms has increased then the medical treatment is of preferred choice. The most commonly used drug for these tumors is octreotide. The recombinant form of octreotide is used which decreases the blood supply of the tumor to reduce its symptoms and also helps to shrink the tumor in size.
Pancreatic neuroendocrine tumors are not so common in their incidence but if found then these are mostly associated with some hereditary syndrome-like multiple endocrine neoplasias, neurofibromatosis, etc. The causes are unknown for these tumors but these are very troublesome tumors due to the hormonal imbalance created by them.
The curability of these tumors depends not only upon the diagnosis and staging of the tumors but also on the type of tumorlike gastrinomas are the most malignant of them all whereas insulinomas are the most common treatable ones of all the pancreatic neuroendocrine tumors.