Treatment of Pancreatic Cancer
Treatment of pancreatic adenocarcinoma depends on the stage of the tumor. All patients should be evaluated for surgical removal of the tumor since this provides the best option for long term survival. The determination of resectablity of the cancer is made after a complete workup of the extent of the tumor. We do not biopsy the tumor prior to the surgery since pathology of biopsy specimens can be erroneous in upto 20% of patients due to sampling errors.
Some of the studies that are performed to evaluate for surgical
removal of the tumor include:
After a comprehensive evaluation of the extent of the cancer
most of the patients fall in to one of three clinical stages:
Treatment of resectable pancreatic cancer
- Resectable (surgically removable) pancreatic cancer
- Unresectable pancreatic cancer
- Metastatic pancreatic cancer
Pancreatic cancer is considered resectable if the tumor appears to be localized to the pancreas without invasion into important surrounding structures such as the mesenteric blood vessels (that supply blood to the intestines) which are located adjacent to the head portion of the pancreas. Furthermore there should be no evidence of metastatic spread to liver or lining of the intestines.
Surgical removal of the tumor is a treatment of choice for patients with resectable pancreatic cancer. The surgery involves removal of all tumor that is visible at the time of surgery and the type and extent of surgery depends on the location of tumor in the pancreas. Since pancreatic adenocarcinoma is an aggresive disease, radical surgery is necessary to remove all the tumor.
Two operations are commonly performed for removal of pancreatic cancer:
The Whipple operation is performed for pancreatic cancer that is located in the head of the pancreas. The common presentation of pancreas with cancer of the head of the pancreas include weight loss, development of jaundice (yellowness of the skin) and occasionally pain in the abdomen and back. 80% of all adenocarcinomas of the pancreas occur in the head of the pancreas.
The head of the pancreas is closely associated with important blood vessels called the superior mesenteric vein and artery. These blood vessels supply blood to the intestine and the liver. An important criteria for removal of pancreatic cancer located in the head of the pancreas is absence of invasion of these blood vessels by the tumor. This is usually determined prior to surgery on a high quality CT scan and sometimes with endoscopic sonography. State of the art CT technology can provide this information in more than 85% of patients with a high degree of accuracy.
A Whipple operation involves removal of the head (first part) of the pancreas and usually about 20% of the pancreas is removed. The bottom half of the bile duct and the first portion of the intestine called the duodenum is also removed and the stomach is preserved. This procedure called the pylorus preserving Whipple operation. Occasionally part of the stomach may be removed and this operation is called the standard Whipple operation.
All patients who undergo a Whipple operation for adenocarcinoma of the head of the pancreas should be considered for chemotherapy and/or radiation therapy after the surgery. Recent studies from John Hopkins Hospital has shown that there is at least an additional 10% benefit is provided for long term survival when adjuvant chemotherapy and radiation therapy provided after the surgery. The medications used depend on the treating institution and preference of the treating oncologist.
Distal pancreatectomy and splenectomy
Adenocarcinoma of the body and tail of the pancreas is treated with a distal pancreatectomy and splenectomy. Tumors of the body and tail of the pancreas are often more aggressive that the tumors of the head of the pancreas and have often undergone metastatic spread to other organs at the time diagnosis. Surgery is only indicated in those patients in whom there is no evidence of metastatic spread. Surgery is often not possible in cancers of the body and tail of the pancreas if the tumor invades a blood vessel called the celiac artery.
Patients in whom the tumor is localized to the body and tail of the pancreas without invasion of the celiac artery and where there no evidence of metastatic spread to other organs should be candidates for surgery. The extent of the removal of the pancreas in the distal pancreatectomy depends on the location of the pancreas since an at least a half a centimeter of normal pancreas beyond visible tumor has to be removed with the cancer to ensure that all the cancer is removed. The surgeon should obtain a pathological evaluation of the cut end of the pancreas at the time of the surgery to ensure that there is no more tumor left behind in the pancreas during surgery.
All patients who undergo distal pancreatectomy and splenectomy for adenocarcinoma of the pancreas should receive chemotherapy and radiation therapy after recovery from surgery.
Locally Advanced Pancreatic cancer
A locally advanced pancreatic cancer has grown beyond the confines of the pancreas to invade surrounding vital structures. Locally advanced pancreatic cancer is not treated by surgery. A common symptom in unresectable pancreatic cancer is severe back pain.
The determination of unresectable pancreatic cancer is based on a careful evaluation of a high quality, detailed, thin section CT scan of the pancreas sometimes with supporting information from an endoscopic ultrasound. The determination of unresectability (surgically not removable) of a pancreatic cancer should be made by an experienced pancreatic surgeon since in selected situations apparent unresectable tumors may be resectable by an experienced pancreatic surgeon with specialized techniques including localized resection of the blood vessels.
A pancreatic cancer in the head of the pancreas is usually unresectable when the tumor has invaded blood vessels called the superior mesenteric artery and vein. Pancreatic cancer in the body and tail of the pancreas is unresectable if the tumor has invaded the blood vessels called celiac artery and the hepatic artery.
Treatment of locally advanced pancreatic cancer include chemotherapy and radiation therapy. The common chemotherapy drugs that are utilized for treatment of pancreatic cancer included 5 flouro-uracil, leukovirin and gemcitidine. Radiation therapy is delivered in daily fractions over a six week period to a total dose of approximately 5,000 rads. The chemotherapy may be administered together or sequentially with the radiation therapy. The exact type of chemotherapy would depend on the treating oncologist.
A small number of patients (approximately 15%), may have an excellent response to chemotherapy and radiation therapy. If the tumor undergoes a lot of shrinkage in response to the chemotherapy and radiation therapy, then surgery may be feasible. Patients with locally advanced pancreatic adenocarcinoma who have completed their treatment and in whom the CT scan suggest excellent response should be evaluated by an experienced pancreatic surgeon for possible removal of the tumor.
Metastatic Pancreatic Adenocarcinoma
Pancreatic adenocarcinoma metastasizes to the liver and/or to the lining of the intestine or peritoneal surfaces. The diagnosis of metastatic pancreatic adenocarcinoma is often made on CT scanning. Approximately 10% of patients who appear to have resectable adenocarcinoma on CT scan staging may be found to have metastatic cancer at the time of surgery. To avoid unnecessary surgery in this group of patients, a diagnostic laparoscopy is routinely performed at USC at surgery for removal of the cancer.
Metastatic pancreatic adenocarcinoma responds poorly to chemotherapy. In general the survival after the diagnosis of metastatic pancreatic adenocarcinoma is often less than one year.The goal of treatment in patients with metastatic pancreatic adenocarcinoma is to provide relief of their symptoms to improve the quality of their lives. In some patients treatment with chemotherapy drug called gemcitidine may lead to improvement in the symptoms and improvement in the performance status (increase in energy and ability to function).
Some of the symptoms that require treatment for improvement of quality of life include: