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:
- Resectable (surgically removable) pancreatic cancer
- Unresectable pancreatic cancer
- Metastatic pancreatic cancer
Treatment of resectable 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
Whipple
Operation
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:
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