Sunday, April 20, 2008

Pancreatic Cancer

The pancreas is an organ located in the upper middle of the abdomen. It is surrounded by the stomach, small intestine, liver and spleen. Pancreatic cancer occurs when there is an uncontrolled growth of abnormal cells in the pancreas or ducts. The exact cause of pancreatic cancer are still largely unknown, but certain factors are known as risk factors. The following factors are known to increase the risk of developing pancreatic cancer; age, gender, race, cigarette smoking, diet, diabetes, environment and family history.

Conducting an imaging study of the gland is often the first step in the pancreatic cancer diagnosis process. This can be achieved through an ultrasound or CT scan of the abdomen that produces a detailed picture of the organ.

While pancreatic cancer survival rates have been improving from decade to decade, the disease is still considered largely incurable.Survival RatesAccording to the American Cancer Society, for all stages of pancreatic cancer combined, the one-year relative survival rate is 20%, and the five-year rate is 4%. These low survival rates are attributable to the fact that fewer than 10% of patients' tumors are confined to the pancreas at the time of diagnosis; in most cases, the malignancy has already progressed to the point where surgical removal is impossible.In those cases where resection can be performed, the average survival rate is 18 to 20 months. The overall five-year survival rate is about 10%, although this can rise as high as 20% to 25% if the tumor is removed completely and when cancer has not spread to lymph nodes.Tumor SizeTumor size does appear to impact survival rates. The larger the tumor, the less likely it is to be cured by resection. However, even large tumors may be removed and a number of patients with tumors greater than 4-5 cm appear to have been cured by surgery.
There is increasing evidence that the best pancreatic cancer outcomes are achieved at major medical centers with extensive experience -- those that perform more than 20 Whipple procedures annually.ProgressionIn patients where a cure is not possible, progression of the disease may be accompanied by progressive weakness, weight loss, and pain. Effective techniques for pain management are widely available today and used by physicians experienced in the care of pancreatic cancer patients. The techniques include nerve blocks and various drugs that can be taken by mouth or injection. There are also a variety of effective techniques available to treat bile duct obstruction which may produce jaundice and stomach obstruction caused by growth of the tumor. Both surgical and non-surgical techniques may be effective.

At present, pancreatic cancer is treated either surgically, through radiation, chemotherapy, or a combination of these techniques.SurgerySurgery, which currently offers the greatest potential for prolonged survival, is generally only performed if the malignancy has not spread beyond the pancreas. In cases where tumors have been deemed resectable (capable of being surgically removed) the standard operation is the Whipple pancreaticoduodenectomy. This procedure involves partial removal of the stomach, complete removal of the gallbladder, a bile duct, head of the pancreas, portions of the small intestine, and regional lymph nodes. In some instances, the entire pancreas must be removed.Due to concern that the standard Whipple was associated with excessive weight loss and nutritional problems, many surgeons use a modified version of the procedure in which the stomach is preserved. It's believed this approach minimizes nutritional problems and is often recommended for those patients with smaller, less extensive tumors.In some instances, tumors are surgically removed, even though the patient is considered non-curable. In these cases, the operation is designed to reduce discomfort associated with the disease.When tumors aren't resectable, surgical intervention may still occur. This would include operating to relieve an intestinal blockage or to perform nerve blocks for pain.Surgical QuestionsIf the tumor is large, can it still be removed?Small pancreatic tumors (less than 2 cm diameter) are more likely to be resectable than larger ones. Nevertheless, the majority of pancreatic cancers located in the head of the gland are larger than that by the time the diagnosis is made and an operation is performed.At the University of Erlangen in Germany, of all resections of tumors in the head of the gland:• 15% were 1- 2 cm in diameter• 33.4% were 2 -3 cm• 23.3% were 3 -4 cm• 27.8% were larger than 4 cm.At UCLA Medical Center over the period 1989 – 1994:• 26% of the resections were for tumors 1 -2 cm in diameter• 17% were 2 -3 cm• 22% were 3 -4 cm• 26% were 4 -5 cm• 9% were larger than 5 cm in diameter.Thus, it should be apparent that no patient should be denied the chance for a resection because of a tumor that is considered "too large."What are the findings at the time of operation that make you decide against resection?In the absence of distant metastases (e.g., peritoneum, serosal surfaces of other organs, lymph nodes outside the usual limits of the resection, liver), resectability depends on whether the tumor has invaded major vascular structures. We usually will not resect if the tumor has invaded the superior mesenteric or portal vein, the superior mesenteric artery or the hepatic artery. However, in some cases, we have removed tumors with venous invasion, excising the involved segment of the vein with the specimen. Vascular continuity is restored by reconnecting the ends of the vessels.Occasionally, when the preoperative discussion has convinced us of the patient's desire for an aggressive approach to the problem, we will undertake the resection with prior knowledge that the vein is involved. In other cases, lateral or posterior involvement of the vein only becomes apparent after the neck of the pancreas has been transected as part of the Whipple. There is evidence that venous resections in those circumstances are associated with a similar survival as seen in patients who undergo resection when the vessels are not involved. Nevertheless, we view this as a palliative resection, and recommend adjuvant treatment later.Is advanced age a contraindication to operation?One author studied 206 consecutive patients over 70 years of age undergoing operation for pancreatic cancer. Forty-two of these patients underwent potentially curative operations, including pancreaticoduodenectomy, total pancreatectomy and distal pancreatectomy.Overall operative mortality rate: 9%Surgical morbidity: 28%Morbidity from medical complications: 12%The morbidity and mortality rates for these operations in these elderly patients did not vary significantly from published results for younger patients.Our experience has been similar. Each patient must be assessed individually, and an evaluation made of the associated risks due to coexistent cardiovascular, pulmonary, and renal disease. Many of our patients who have undergone Whipple resection are over the age of 80; some patients under age 65 have been unacceptable operative risks. At UCLA, the overall operative mortality rate for pancreatic resection since 1995 is less than 1%.Should the tumor be removed if cure is not possible?Since the Whipple resection is now done around the world with operative mortality rates less than 5%, pancreatic surgeons have discussed the possibility that it might be done for palliation. Indeed, there is anecdotal evidence that patients may live longer and enjoy a better quality of life if the tumor is removed than if it is not.Several recent reports which supported the performance of the Whipple for palliation were not appropriately designed to answer the question, however. One recent study from Japan in which patients with liver metastases underwent simultaneous resection of both the tumor and the liver lesions failed to show any benefit of resection. We have not performed resections in patients with hepatic, peritoneal, or other distant metastases. We have done knowingly non-curative resections in selected patients with locally extensive disease (vascular or adjacent soft tissue involvement), with the hope that it would provide palliation. Our experience is encouraging.What kind of operation should be done? Standard Whipple versus Pylorus-preserving Whipple versus Radical Resection?The standard operation for resectable pancreatic cancer in the head of the gland is the Whipple pancreaticoduodenectomy. This involves a partial removal of the stomach, removal of the gallbladder and distal common bile duct, head of the pancreas, duodenum, proximal jejunum and regional lymph nodes. Reconstruction requires a pancreaticojejunostomy, hepaticojejunostomy, and a gastrojejunostomy.Because of concern that the standard Whipple resection was associated with excessive weight loss, and nutritional problems, many surgeons have adopted the pylorus preserving modification. Here the stomach and pylorus are preserved, which maintains gastric reservoir function, and postoperative gastric emptying is closer to normal. It is widely believed that the modified procedure minimizes the nutritional disturbances, and that it can be done more quickly and easily. It has generally been accepted that this does not compromise the chance for cure of the cancer.Recently, we completed the only randomized, prospective study of the standard Whipple and the pylorus preserving variant. There were no differences in any of the postoperative complications, nutritional parameters, the frequency or type of gastrointestinal symptoms, weight loss, or in the ease or time required to perform the two operations. The 22 patients in the study were all operated upon by one surgeon, and were evaluated 9-12 months after the operation. Thus, the procedures appear to be equivalent. We did not compare the operations in regard to their efficacy as treatment for the underlying cancer, however. We now perform the two operations interchangeably, and usually select the pylorus preserving modification in patients with smaller, less extensive tumors.A more radical resection has been advocated by a number of surgeons in Japan. This operation involves a wider resection of peripancreatic soft tissue and lymph nodes, often with routine removal of segments of the superior mesenteric and portal veins, as well. Operative mortality rates were not increased significantly by this more aggressive approach. Although there is some evidence that this operation was associated with a longer survival, a critical analysis of the data does not support that conclusion. A prospective study in which approximately matched patients are randomized to both the standard and radical operations is needed. The operation is infrequently done in the United States.
Radiation and ChemotherapyFor patients whose tumors cannot be completely removed surgically, treatment generally focuses on the prevention and/or management of symptoms through radiation and/or chemotherapy.Radiation therapy is most often used to relieve painful disease sites, while chemotherapy is prescribed to reduce the rate of tumor growth and thus prolong survival. In some instances, radiation and chemotherapy are utilized together.Additionally, in a new approach developed by City of Hope Cancer Center in Duarte, Calif., radiation, chemotherapy and surgery are combined. The approach consists of 24-hour treatment with the chemotherapeutic agent gemcitabine, followed by surgical removal of the tumor, and radiation therapy administered locally during the operation. Post-operative treatment includes gemcitabine and external radiation.

Other Sources of Pancreatic Cancer Information
The Internet has many sources of information about pancreatic cancer; this section represents a growing archive of those resources. Here are the ones we've found so far:
Cancer Care, Inc.Hirshberg Foundation Grants are available for counseling and financial assistance.Johns HopkinsNational Familial Pancreas Tumor Registry at Johns HopkinsThe Lustgarten Foundation
Pancreatic Cancer Action NetworkCancer Legal Resource CenterA Joint Program of Loyola Law School & the Disability Rights Legal Center
National Cancer Institute
American Cancer Society
Cancer, Carcinoma and Tumor Resource InformationA comprehensive site for cancer related resources and links.
The journal PANCREASnote: "Nutritional Links to Plausible Mechanisms Underlying Pancreatic Cancer Executive Summary" will appear in the November issue, and should be available either a little before or on Oct. 24, 2003Community Care @ Home"trusted partner for quality care in the comfort of your home"
CenterWatch's Clinical Trials Listing
M.D. Anderson Cancer Center Pancreatic Tumor Study Group
CyberKnife SocietyA non-profit organization dedicated to educating the public on a range of medical conditions for which stereotactic radiosurgical treatment has proven to be of benefit.
Http://www.ctrintegrative.orgThe Center is a non-profit organization whose goal is to offer an operating clinic that offers a myriad of alternative and complementary therapies available to all populations.
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1 comment:

Advin Charles said...

Pancreatic is responsible for producing insulin which regulates the sugar level in the body. Pancreatic cancer survival rate can go up if the person with cancer will be proactive in his or her well being.

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