Background : Staging : Treatments : Radiation Therapy

BACKGROUND

The pancreas is located in the abdomen and is surrounded by the stomach, intestines, and the main blood vessels called the aorta and vena cava. The organ is divided into three portions. The widest portion is located next to the duodenum and is called the head. The central portion is called the body and the narrowest part near the spleen is called the tail. The pancreas is part of the endocrine system which is involved with digestion and metabolism. It secretes enzymes directly into the intestines to aid in digestion, particularly the breakdown of fats. In the pancreatic head, the duct which carries these enzymes joins a duct from the from the gallbladder and liver called the common bile duct. This empties directly into the duodenum to digest food. The pancreas also produces insulin, which is released into the bloodstream to lower the level of sugar. Cancer of the pancreas can begin in any part of the gland.

Epidemiology:
Approximately 28,000 cases of pancreatic cancer are diagnosed each year in the United States. The typical age at diagnosis is 70 years and males are more commonly affected. Pancreatic cancer is the forth leading cause of cancer death in adults. Risk factors for the disease include cigarette smoking (doubles the risk), a high fat diet, chronic pancreatic inflammation (pancreatitis), and exposure to certain chemicals (benzidine, B-naphthylamine). Diabetics are twice as likely to be diagnosed with pancreatic cancer.

Signs and Symptoms:
Pancreatic cancer is difficult to detect in its early stages. Patients are typically diagnosed when the tumor blocks the ducts carrying bile and digestive enzymes causing a condition called jaundice (yellowing of the skin). Tumors of the body or tail of the pancreas may go undetected until they invade the spine causing back pain. Other common symptoms include loss of appetite, unexplained weight loss and fatigue.

Diagnostic tests:
If your doctor suspects pancreatic cancer, one or more of the following tests may be ordered:

Ultrasound:
This test uses sound waves to look at the liver, gallbladder, and bile ducts. Tumors of the head of the pancreas cause the bile ducts to be enlarged or dilated.

CT or MRI scan:
These scans show cross sections of internal anatomy. Most tumors of the pancreas can be seen on this type of scan. These tests are needed to help determine if the cancer can be removed surgically. Sometimes a biopsy can be performed during the scanning process to confirm the diagnosis.

ERCP:
This test is done by a Gastroenterologist who passes a camera down the throat, past the stomach, and into the duodenum. A small tube is used to inject dye into the pancreatic and bile ducts to evaluate for a possible blockage.

STAGING

Staging is the term which refers to categorizing how advanced the cancer is. The stage of disease will determine to appropriate treatment Stage I disease involves only to pancreas. Stage II means that the cancer involves nearby organs in the abdomen. Stage III is when cancer is seen in the lymph nodes, which are part of the immune system. In stage IV disease, the cancer has spread to other organs in the body. This spread is typically through the bloodstream through a process called metastasis. Unfortunately, most patients present with advanced stage disease (stage III or IV).

TREATMENT OPTIONS

Surgery:
About 10-20% of patients are candidates for surgical resection of the pancreas. This surgery is called a Whipple resection after the surgeon who described the procedure. Surgery is the only curative treatment for pancreatic cancer. After surgery, the results are improved by adding both chemotherapy and radiation therapy to the area where the tumor had been removed.

Radiation Therapy:
This consists of x-rays which are directed at the tumor to kill the cancer cells. Radiotherapy is commonly used after surgery in early stage pancreatic cancer and has been shown to improve the survival rates. In cases where surgery is not possible, radiation and chemotherapy are used as the primary form of treatment. Click here for more info.

Chemotherapy:
This refers to cancer fighting medications which are given through and I.V. into the bloodstream. Chemotherapy can be used by itself but is typically used together with radiation therapy. Commonly used chemotherapy drugs are 5-FU and gemcytobine.

RADIATION THERAPY

If radiation therapy is recommended, the patient will be scheduled for a treatment planning session called simulation. X-rays and/or CF scans are used to identify the tumor and help the Radiation Oncologist target the tumor. The treatment is delivered from the front, back, and usually both sides. Special devices called "blocks" are made to shape the x-ray beam and block out areas which do not need to be treated. Care is taken to minimize the dose to critical organs such as the kidneys and spinal cord. Once a treatment plan is prepared, the patient will come in for daily treatments lasting about 15 minutes each. Treatment is delivered Monday through Friday for four to seven weeks depending on the circumstances.

Side Effects:
The side effects seen with radiation and chemotherapy for pancreatic cancer include nausea,vomiting, poor appetite, diarrhea, weight loss, and fatigue. Nausea can now be frequently controlled with newly developed medications. Diarrhea is also well controlled with medicines in most cases. The fatigue from therapy is typically temporary. Patients' weight should be monitored during therapy and nutritional guidance given when necessary.

Follow-up:
After completing treatment for pancreatic cancer, patients are seen regularly for follow-up visits. Blood tests and x-rays may be ordered to evaluate the response and guide further treatment. The exact timing of any follow-up scans is determined by the physicians who treated the patient.

 

Robert P. Zimmerman, MD