Approximately five thousand cases of gallbladder cancer are diagnosed each year in the United States. Most of these cases are found incidentally while a person is being examined for potential gallstones. Gallbladder cancer has a very poor prognosis, typically because the symptoms tend to be very vague and nonspecific. In addition the gallbladder is anatomically difficult to access surgically, making surgical interventions problematic. These factors often delay the diagnosis of gallbladder cancer until it is relatively advanced and make treatments more difficult.
The risk of gallbladder cancer increases with age. Women are two to six times more likely to get gallbladder cancer than men. Gallbladder cancer is found more commonly in caucasians than in the black population.
Approximately 70 to 90% of people who come down with gallbladder cancer will also have a gallstone present. This makes the presence of gallstones one of the most important risk factors for the development of gall bladder cancer. It should be noted however that a vast majority of people with gallstones will never get gallbladder cancer. In fact, the rate of gallbladder cancer in patients with gallstones is only approximately 1 to 3%. The exact relationship between gallstones and gallbladder cancer is uncertain.
Another risk factor for gallbladder cancer is an uncommon condition associated with chronic gallstones known as porcelain gallbladder. Porcelain gallbladder is a condition where the interior wall of the gallbladder becomes calcified and smoothed, looking much like a porcelain surface. This condition is almost exclusively found in people with gallstones. The incidence of gallbladder cancer in patients with a porcelain gallbladder is quite high. Various studies have estimated the incidence to be anywhere from 15 to 50%.
The presence of small polyps within the gallbladder can be a risk factor for gallbladder cancer. These polyps are small outgrowths within the mucosal wall of the gallbladder, and are typically found incidentally when a patient is being evaluated for a different gallbladder issue. Gallbladder polyps can be benign or malignant, and the exact association between them and gallbladder cancer is not well established.
There are two infections which have been associated with increased risk of gallbladder cancer. The first of these is a Salmonella infection. Several studies have shown an increased risk of gallbladder cancer in people with chronic Salmonella infections of the gallbladder. The exact mechanism by which a chronic Salmonella infection can cause the gallbladder cancer is not well understood.
The other infection which has shown an association with gallbladder cancer is Helicobater pylori. H pylori is the same bacteria which is commonly associated with peptic ulcer disease. Once again, the exact association between this infection and gallbladder cancer is not well understood.
Signs and Symptoms
Gallbladder cancer can typically progress for many years without any symptoms. The first symptoms to appear are often nonspecific and can easily be confused with many other conditions. Patients will often complain of pain, lack of appetite, vomiting, and nausea. The symptoms are similar to what is seen with gallstones. As gallbladder cancer advances to later stages, a person will often become chronically tired and lose a significant amount of weight.
Many patients with gall bladder cancer will also become jaundiced. This means that there skin and eyes will become notably yellow.
Methods of Diagnosis
As with many cancers, the sooner gallbladder cancer is detected, the better the outcome can be. Because of the nonspecific nature of most of the symptoms, gallbladder cancer is typically detected by imaging the gallbladder directly.
The most commonly used imaging technique for any condition related to the gallbladder is an ultrasound. These tests are inexpensive, easy to perform, and not uncomfortable for a patient. Unfortunately there are limitations to the effectiveness of an ultrasound. These tests are highly dependent on the skill of the operator, and have a high rate of missing a diagnosis.