Pancreatic cancer begins in the tissues of your pancreas, a large organ that lies horizontally behind the lower part of the stomach. Pancreatic cancer occurs most commonly in men between the ages of 35 and 70, it is the fourth most common cause of cancer mortality (behind lung cancer, colorectal cancer and breast cancer). Pancreatic cancer is usually an adenocarcinoma and it usually arises from the pancreatic duct cells which make up the major part of the pancreas.
Cause of pancreatic cancer
Pancreatic cancer is caused by damage to genes, but it is not known exactly why this damage happens. Evidence suggests that it is linked to exposure to carcinogens such as; cigarettes, food high in fat and protein and food additives. Possible predisposing factors are chronic pancreatitis, diabetes mellitus and chronic alcohol abuse.
There is some evidence that people who don’t eat many fresh vegetables and fruits are more at risk from pancreatic cancer. Being overweight may cause a small increase in the risk of pancreatic cancer. Some industrial chemicals called chlorinated hydrocarbon solvents have been linked to pancreatic cancer, although they are unlikely to be a major factor. Other chemicals and exposures that have been linked to an increased risk of pancreatic cancer in some studies include pesticides, radiation, nickel, chromium and iron.
The average age of onset of pancreatic cancer is between 70 to 80 but heavy smokers and heavy drinkers present with pancreatic cancer an average of seven to 10 years earlier than the rest of the population.
Signs and symptoms of pancreatic cancer
The most common are weight loss, abdominal or low back pain, jaundice and diarrhea.
Other more general effects include; fever, skin lesions, depression, anxiety and a premonition of impending death. Ascites ( fluid retention in the abdomen ) can be a sign of pancreatic tumors.
It is very difficult to diagnose pancreatic cancer as the pancreas is so deep within the body and symptoms vary depending on the exact location of the tumor in the pancreas and which cells or function of the pancreas is affected by the tumour or cancer. Unfortunately the symptoms of pancreatic cancer can also be quite vague and non specific and may be caused by many other more common and less serious conditions.
Pancreatic cancer typically spreads rapidly and is seldom detected in its early stages, which is a major reason why it is a leading cause of cancer death. Pancreatic cancer specialists believe that anyone over 50 who develops diabetes and has unexplained weight loss should be investigated for other pancreatic disease. Courvoisier sign defines the presence of jaundice and a painlessly distended gallbladder as strongly indicative of pancreatic cancer and may be used to distinguish pancreatic cancer from gallstones.
Treatment for pancreatic cancer depends on the stage and location of the cancer as well as on your age, overall health and personal preferences. The first goal of pancreatic cancer treatment is to eliminate the cancer, when possible. When that isn’t an option, the focus may be on preventing the pancreatic cancer from growing or causing more harm. Pancreatic cancer is relatively resistant to medical treatment and the only potentially curative treatment is surgery. Radiation therapy for pancreatic cancer can palliate pain but does not affect the patients survival.
Gemcitabine was approved by the US FDA in 1998 after a clinical trial reported improvements in quality of life in patients with advanced pancreatic cancer. Management of pain and other symptoms is an important part of the treatment of advanced pancreatic cancer.
Pancreatic cancer often has a poor prognosis, even when diagnosed early and the median survival period from the time of diagnosis until demise is arguably the worst of any of the cancers. The best predictors of long term survival after surgery are a tumor diameter of less than 3 cm, no nodal involvement, negative resection margins, and diploid tumor DNA content.
Due to difficulties in diagnosis, the aggressive nature of pancreatic cancer and the limited systemic treatments available, the five-year survival rate for patients who have pancreatic adenocarcinoma is only about 5%. For pancreatic cancer that cannot be removed completely with surgery, or cancer that has spread beyond the pancreas, cure is not currently possible and the average survival is usually less than 1 year.