pancreatic cancer adenocarcinoma

The most common type of cancer of the pancreas is an adenocarcinoma of the pancreas. 85% of all cancerous tumors of the pancreas are adenocarcinomas. Pancreatic adenocarcinoma is the 4th leading cause of cancer deaths in men and women in the United States. The American Cancer Society estimates that each year 29,000 American are diagnosed with adenocarcinoma of the pancreas and approximately 28,000 die of pancreatic cancer.

About 20-40% of patients with pancreatic cancer appear to have the cancer contained entirely within the pancreas at the time of the diagnosis. Surgical removal of the tumor is recommended in this group of patients and this provides the best option for long term survival. Surgery for pancreatic cancer is a highly specialized operation and therefore the patient should be evaluated by a surgeon who is highly experienced in treating this disorder.

About 60-80% of the patients are found to have a locally advanced cancer because it is invading into the surrounding tissues outside the pancreas or where the cancer has metastasized (spread outside of the pancreas).

Risk factors for cancer of the pancreas:
Some of the risk factors for cancer of the pancreas include:

Cigarette Smoking: Cigarette smoking is the single most risk factor for pancreatic cancer. Approximately 30% of pancreatic cancers are thought to be related to excessive cigarette smoking.

Diet: A diet high in meat and fats increase pancreatic cancer risks while fruits, vegetables and dietary fiber appear to have a protective effect.
Diabetes Mellitus: While it is not clear whether diabetes mellitus is a risk factor for pancreatic cancer often patients develop diabetes few months to two to three years prior to manifestation of their cancer. Development of diabetes in an elderly patient should raise concern for pancreatic cancer and lead to a work up for pancreatic cancer.

Chronic pancreatitis: Chronic pancreatitis is long term inflammation of the pancreas. This condition is associated as an increased risk for pancreatic cancer.
Family History: Cancer of the pancreas seems to run in some families. An inherited tendency to develop this cancer may occur in about 5 to 10% of all cases of pancreatic cancer. Some of the DNA changes that give rise to pancreatic cancer can be recognized by genetic testing.

Staging and treatment of pancreatic cancer:
A simplified staging of pancreatic cancer places patients in the following groups for determining appropriate treatment:

Surgically resectable (removable) pancreatic cancer
Advance cancer that is surgically not removable with no evidence of spread to other organs

Metastatic cancer or cancer that has spread to other organs
Resectable (surgically removable) pancreatic cancer
For patients whose tumors are in the pancreas based on information from preoperative staging removal of the tumor by surgical means is the optimal form of therapy.

The type of the surgery depends on the location of the tumor. For tumors that are located in the first part or the head of the pancreas a whipple operation is the required treatment.

For patients whose tumors are located in the body and tail of the pancreas removal of the bottom half with a distal pancreatectomy together with removal of the spleen is the preferred form of surgical treatment.

All patients who undergo resection (removal) of the pancreas will require chemotherapy and/or radiation therapy after the surgery.

Locally advanced cancer:
Here the cancer has grown outside the pancreas to involve surrounding structures particularly blood vessels that are closely associated with the pancreas such as the superior mesenteric artery and superior mesenteric vein. Invasion of the cancer into these blood vessels precludes surgical removal of the tumor.

A determination of a locally advanced cancer should be made by an experienced surgeon based on careful evaluation of radiological (x-ray) studies such as a high quality CT scan. It is important to note that CT scans that are not done in centers specialized in the treatment of pancreatic cancer may not provide optimal information for staging of patients with pancreatic cancer. Removal of the pancreas for pancreatic cancer is a highly specialized operation and therefore the evaluation of the patient for possible surgery should be by a surgeon who is highly experienced in treating this disorder.

In patients who are determined to have unresectable cancer at a center specialized in the treatment of pancreatic cancer, treatment with chemotherapy and/or radiation therapy is recommended since this treatment has been shown clinical studies to provide improved survival.

Some patients with locally advanced tumor may have excellent response to chemotherapy and/or radiation therapy and shrinkage of the tumor may allow an experienced pancreatic surgeon to remove the cancer.

Metastatic pancreatic cancer:
In patients with metastatic pancreatic cancer the tumor is found to have spread outside of the pancreas. The common sites for spread of the tumor is to the liver and to the lining of the intestines or peritoneal surfaces. In general the prognosis is poor when pancreatic cancer is metastatic and treatment is directed toward relief of symptoms to provide a good quality of life. In some patients chemotherapy may provide an improvement in their symptoms.