The Pancreas
The pancreas is a small, organ which lies just under the curvature of the stomach and deep within the abdomen. The function of the pancreas is complicated, but one could say that it primarily does two things. It produces enzymes which are useful for the digestion of food and it secretes hormones which, among other things, help maintain and regulate body blood sugar levels.
Pancreatic Cancer
What is Pancreatic Cancer?
Malignant cancer is a tumor (or growth) in which an aggregation of individual cells begins to grow in a rapid, uncontrolled and abnormal manner; and which may spread by aggressive local extension or by the seeding of other organs through blood vessel channels or via the lymphatic system. Further, under the microscope, the appearance and arrangement of these carcinoma cells can appear as duct-like (or “adeno”) giving the term adenocarcinoma to this most common form of pancreatic cancer.
About three-quarters of exocrine tumors of the pancreas arise in the head and neck of the pancreas Some of these carcinomas arise in the body of the organ, and less than ten percent arise in the tail of the pancreas
Endocrine tumors have a different natural history than the exocrine tumors. They tend to be slower growing and have a better prognosis. The treatment of neuroendocrine tumors of the pancreas is distinct from that of adenocarcinoma of the pancreas.
Staging of Pancreas Cancer
What are the Stages of Pancreatic Cancer?
Stage I:
pancreatic cancer includes tumors which have not spread into certain proscribed sensitive areas and which have no involved regional nodes or distal metastasis.
Stage II:
includes tumors which have spread into the duodenum, bile duct, or “peripancreatic” tissues AND which have no involved regional nodes or distal metastasis.
Stage III:
cancer includes tumors which may have OR may not have spread into these aforementioned areas and which have involved regional nodes, but which show noevidence of distal metastasis.
Stage IV – A:
includes tumors which have spread into the stomach, spleen, large bowel OR the adjacent large vessels AND which have involved regional nodes, but show no evidence of distal metastasis.
Stage IV – B:
includes pancreatic tumors of any kind with node status of any kind AND with evidence of distal metastasis.
Diagnosis of Pancreatic Cancer
How is Pancreatic Cancer Diagnosed?
Signs and Symptoms
Generally, the most common symptoms of adenocarcinoma of the pancreas include loss-of-appetite, weight loss, abdominal discomfort and nausea. As these are all fairly non-specific symptoms, there is often delay in getting to the final diagnosis. The most common physical sign of pancreatic cancer is jaundice, with or without associated itching.
Laboratory
Often lab results show a high bilirubin (bile pigment found in the serum) and elevated liver function enzymes. The CA 19-9 marker, a Lewis blood group-related mucin, is frequently elevated in adenocarcinoma of the pancreas.
What are the steps in the work up and treatment of the tumor in the pancreas
The following questions are sequentially addressed when a patient is seen at my clinic with a pancreas mass
- Where is the tumor in the pancreas and has it spread
- What is the likely type of the tumor (adenocarcinoma or a less aggressive tumor type)
- Is the tumor surgically removable or what other approaches to follow
- Is laparoscopic approach possible for your tumor type
- Is chemotherapy and/or radiation therapy indicated
Staging Studies
How do you stage pancreas cancer?
- Ultrasonography Dynamic
- Spiral CT
- scan with contrast
- MRI Scan
- Endoscopy/ERCP/Endoscopic ultrasound
- Staging Laparoscopy/Laparoscopic ultrasound
Surgery
What is the surgical treatment of pancreatic cancer?
A denocarcinoma of the pancreas
The most common type of cancer of the pancreas is an adenocarcinoma and form 85% of all pancreatic tumours. Only about 20 to 40% of patients with adenocarcinoma of the pancreas have a tumor that is confined to the pancreas at the time of diagnosis. The 5-year survival for patients who undergo surgical resection of adenocarcinoma of the pancreas is about 20 to 40%.
Surgery is a treatment of choice for patients who have adenocarcinoma of the pancreas that is surgically removable. Careful selection of patients for surgery is important. since surgical removal is associated with the best outcome diagnostic testing to identify patients suitable for surgery is extremely important. Appropriate diagnostic testing will also avoid unnecessary surgeries in patients whose tumors are too advanced for surgical removal. We also do scans for heart and lungs to make sure this group of patients are fit for surgery as most of the patients are of elderly age group. I have done in patients upto 78 years and would offer the operations in age group up to 80 years and beyond if they are extremely fit. I have maintained a nil 30 day mortality for all my Whipple’s operation at NUH over the last 4 years.
The surgical procedure that is done depends on the location of the tumor in the pancreas. For tumors that occur in the head (which is the first part) of the pancreas, the Whipple operation is usually performed. For tumors that are located in the body and tail of the pancreas a distal pancreatectomy that removes the distal half of the pancreas is recommended. The results of surgery have dramatically improved in the last two decades such that today the mortality (death) rate from surgery is less than 5% in experienced hands.
Many patients will require chemotherapy and radiation therapy after the surgery based on lymphnode status and microscopic margins of clearance. Patients with unresectable tumors are often treated with chemotherapy and radiation therapy, and in some patients response to the treatment may allow subsequent surgical removal of the tumor.
Other tumors in the pancreas
15% of tumors that develop in the pancreas are not adenocarcinomas and these tumors often have a far better prognosis. Since many patients with these tumors are often cured after surgery, identification and aggressive treatment of these tumors is important.The tumor types that are found in this group include:
- cystic tumors or neoplasms including mucinous cystadenoma and serous cyst adenoma
- islet cell tumors also called neuroendocrine tumors
- papillary cystic neoplasms
- acinar cell tumors of the pancreas
The majority of these tumors are non-malignant or benign, however even malignant tumors have five year survival rates in the order of 40 to 80% depending on the tumor type. In view of the excellent outcome, aggressive surgical therapy is indicated for these tumors, and the part of the pancreas that is affected by the tumor is removed.
My emphasis emphasis has been to preserve as much of the pancreas as possible when removing benign and precancerous tumors to minimize the consequences of removal of large amounts of the pancreas such as diabetes and malabsorption (inability to digest food). I offer procedures like central pancreatectomy where only the central portion of the pancreas is removed for tumors in this location preserving the head and body and tail of the pancreas. I also offer laparoscopic procedures that emphasize minimal access surgical technique for more rapid recovery like laparoscopic distal pancreatectomy for benign tumors of the pancreas.
Locally Advanced Tumours
Generally, in locally advanced unresectable adenocarcinoma of the pancreas, chemotherapy plus radiation (in one form or another) is often prescribed as standard therapy. As early as 1981, a landmark report by the Gastrointestinal Tumor Study Group demonstrated significant survival advantage to those patients with locally unresectable adenocarcinoma of the pancreas who had received both chemotherapy and radiation. This combination chemoradiation gave better outcomes than either chemotherapy or radiation alone.
Pancreas Preserving Surgery
The pancreas plays an important role in the digestion of food and in regulation of blood sugar. Loss of pancreatic tissue after surgical removal increases the risks for the development of diabetes mellitus and mal-absorption of food.
Preservation of pancreatic tissue is an important goal during surgery for pancreatic and biliary diseases to reduce the risks of loss of pancreatic tissue.
The procedures we offer as an alternative to the Whipple operation or massive pancreas removal include
Central pancreatectomy
This procedure is indicated for patients who have low-grade malignant or benign tumors in the neck (in the middle of the pancreas). Removal of tumors in this area often require removing a large portion of the normal pancreas by surgical procedures such as either an extended Whipple operation or a subtotal pancreatectomy (removal of 80% of the pancreas).
We offer a highly specialized surgical procedure that removes only the tumorous portion of the neck of the pancreas. We therefore preserve the head of the pancreas avoiding the Whipple operation and also the body and tail of the pancreas.
Spleen preserving distal pancreatectomy
This procedure is indicated for patients with low-grade malignancy or benign disorders of the tail of the pancreas. The spleen is often removed with a standard distal pancreatectomy, however, in patients with low-grade malignancy or benign disorders of the tail of the pancreas there is often no indication for a splenectomy. We offer a procedure that would remove only the pancreas while preserving the spleen.
Enucleation of pancreatic islet cell tumors
Many functional pancreatic islet tumors such as insulinoma and gastrinoma are small tumors usually less than 1 to 2cm. Furthermore the tumors are often on the surface of the pancreas. The tumors have a lining around them that separates them from the pancreas.
An operation called enucleation is often performed for these tumors. In this operation the tumor is shelled out from the pancreas without removing any pancreatic tissue. We also offer Laparoscopic enucleation of a pancreatic islet cell tumor. This allows rapid recovery, early discharge from hospital and early return to work.
Wide resection of Ampulla Vater
This procedure is offered to patients with ampullary polyps or other benign disorders of the ampulla. Patients usually present with pancreatitis or jaundice. The Whipple operation is usually offered for these benign conditions. We prefer local resection of the ampulla vater for villous adenomas since the pancreas and duodenum are preserved. We widely remove the ampulla and then re-implant the cut ends of the bile duct and the pancreatic duct into the duodenum.
Isolated resection of the third and fourth portion of the duodenum
This procedure is an option for patients with tumors in the third and fourth portions of the duodenum. This procedure is performed to avoid a Whipple operation. In this surgical procedure only the third and the fourth portion of the duodenum is removed and the cut end of the intestine are then sutured together.
What about neuroendocrine (islet cell tumors)?
Neuroendocrine tumors of the pancreas (islet cell tumors) are much less common than tumors arising from the exocrine pancreas. About 75% of these tumors are “functioning.” That is they are found to be producing symptoms related to one or more of the hormone peptides that they secrete
Except for insulinomas, very roughly about 60% of islet cell tumors are malignant. This rate contrasts with about 10% of insulinomas which are eventually found to be malignant. The sites of metastasis of islet cell tumors most commonly are the liver and the lymph nodes in the vicinity of the pancreas.
Carcinoid cancer is the most common of the neuroendocrine tumors. The symptoms and signs of carcinoid tumors range widely, and depend on the location and size of the tumor, on the presence of metastases, and secretions. They can appear to the surgeon as firm nodules bulging into the intestinal lumen (can originate from pancreas, lungs, thymus, appendix, and ovaries, etc.), with possible local expansion, and possible metastases to mesenteric lymph nodes, liver, ovaries, peritoneum, testes, prostate, spleen and other anatomic locations. Carcinoid tumors can secrete any number of hormonal, growth and other factors. The treatment of choice for localized islet cell tumors is generally curative surgery.