The pancreas is a deep seated organ in the abdomen which lies horizontally from the right to left, just below the liver. The pancreas is divided into four parts, namely the head, neck, body and tail. Pancreatic tumours include those that are solid in nature, and those that have a large fluid component (cystic tumour of the pancreas). The most common solid pancreatic tumour is a cancer of the lining of the pancreatic ducts known as adenocarcinoma of the pancreas. The next most common type of solid tumour arises from cells in the pancreas which are known as neuroendocrine cells, hence they are known as pancreatic neuroendocrine tumours (PNET).
Symptoms arising from pancreatic tumours depend on their location. In the case of PNET, it also depends on whether the tumours are functional, ie if they produce excessive hormones which cause clinical syndromes. Tumours in the head of pancreas may cause jaundice, pain and vomiting. Tumours arising from the neck, body and tail of pancreas may be silent when small, and only produce symptoms of pain and discomfort when they get bigger.
Diagnosis of a pancreatic tumour is on imaging, most commonly with a CT or MRI scan. If a cancer is suspected, additionally tumour markers CA 19-9 and CEA may be performed. Although these tumour markers may indicate the presence of a cancer, a normal level does not exclude a cancer, nor is a raised level confirmative of one.
In the case of PNET, the tumour markers that are associated with it are Chromogranin A and Pancreatic polypeptide. Furthermore, when a pancreatic neuroendocrine cancer is suspected, further imaging with a radionuclide scan may be performed to examine if the cancer has spread. Confirmation of the type of tumour may be obtained through a biopsy. This is commonly done via endoscopy with the aid of an ultrasound (endoscopic ultrasound-EUS).
Pancreatic ductal adenocarcinoma
This is the most common cancer of the pancreas. Tumours in the head of pancreas often cause jaundice whilst those in the rest of the pancreas cause abdominal pain as the predominant symptom.
Pancreatic Neuroendocrine Tumour (PNET)
Most PNET are small and nonfunctional. The most common functional tumour is an Insulinoma, which produces insulin in an excessive manner. This can cause fainting and sweating spells due to low blood sugar levels. Surgery is indicated for functional tumours. For non-functional tumours, the indication for surgery is based on the risk of cancer which is related to the size of the tumour, and also on the risk profile of the patient as well as the risks associated with the surgical procedure required.
Cystic tumour of the pancreas
This entity is also known as cystic neoplasm of the pancreas. Cystic tumours in the pancreas can be benign, malignant or potentially malignant. When a cystic tumour in the pancreas is deemed to be benign, surgery is performed when symptoms are present that are attributable to the tumour. Else such tumours can be left alone. When a cystic tumour is deemed malignant, surgery is indicated. When a cystic tumour is deemed to be potentially malignant, the treatment will depend on the magnitude of the risk of turning malignant, the safety profile of the surgery that is required, the fitness of the patient for surgery as well as the age of the patient. Very often, this category of cystic tumour is further assessed with an endoscopic ultrasound (EUS).
Prior to surgery, additional procedures to decompress obstruction of the bile ducts if present might be undertaken. This can be in the done with a tube inserted into the bile duct via endoscopic (ERCP) access, or with a tube inserted directly through the skin into the liver known as Percutaneous Transhepatic Biliary Drainage (PTBD). The operative procedure depends on the location of the tumour.
Also known as pancreaticoduodenectomy, this operation is undertaken for tumours arising from the head of pancreas. It entails removal of the head of pancreas, together with part of the stomach, the first part of the small intestine as well as the bile duct. In some cases, the stomach may not be removed, and this is known as pylorus preserving pancreaticoduodenectomy (PPPD).
This is done for removal of pancreatic tumours that are located in the neck, body or tail of pancreas. The spleen may also be removed as part of the operation, but it may also be left intact when the nature of the tumour allows it. This operation is often carried out via laparoscopic (keyhole) access. Robotic surgery is also done for this type of surgery. Large tumours with extension beyond the confines of the pancreas may still require conventional open surgery.
Chemotherapy and radiotherapy
These may be administered following surgery to improve the chances of disease free survival and cure. In cases where the cancer has already spread, or is too extensive for surgery, or where the cancer has recurred, chemotherapy and occasionally radiotherapy is offered as a palliative treatment.
Patients who have been operated on for pancreatic cancers will be on surveillance for possible recurrence of the tumour. This is done through scans as well as blood tests for cancer markers. Patients will also be monitored for possible development of deficiency of digestive enzymes or blood sugar regulatory hormones that are produced by the pancreas.