No obvious cause for cancer of the pancreas has been identified; it is, however, about twice as common in cigarette smokers as in non smokers.
The bile duct, which conveys bile from the liver to the intestine, passes through the head of the pancreas, and a pancreatic cancer at that site, which is the most common, makes itself known by compression of the bile duct, causing painless progressively deeping jaundice (from the retention of bile salts in the bloodstream), the passage of pale bulky stools,, and dark urine ( from the absence of bile pigment.)
Surgical removal of such a pancreatic cancer is technically possible, but, being a matter of appreciable risk and with considerable post operative morbidity, it is seldom performed. The tumor spreads to adjacent lymph nodes and thence to the liver, but if the disease is not treated death usually occurs from obstructive liver failure long before this metastatic spread.
There is a bright side to this picture. The tumor is usually rather slow growing, and it occurs predominantly in the elderly. The obstructive jaundice can be relieved by a relatively minor by pass operation, allowing the jaundice to clear, and the patient may then enjoy reasonably good health for many months and sometimes years.
Cancer of the body of the pancreas, not obstructing the bile duct, is notoriously difficult to diagnose because the symptoms are so vague. The usual story is of diminishing appetite and loss of weight, with later constant uper abdominal discomfort and backache.