Definition and Overview
Carcinoma of the gallbladder, as the term suggests, is cancer that originates in the gallbladder.
The gallbladder is a small pear-shaped organ located behind the liver. It is mainly responsible for storing bile, a fluid that helps with digestion by breaking down fats into fatty acids. However, it is not considered an essential part of the body because the digestive system can still function the same way even if the gallbladder is surgically removed.
Gallbladder cancer occurs when malignant cells form in the gallbladder tissue, usually starting in the inner or mucosal layer and then spreading to the outer or serosal layer as the disease progresses. Just like other types of cancer, the condition can also spread or metastasise. Common sites of spread are surrounding organs such as the bile ducts, pancreas, small intestine, stomach, and colon. Gallbladder cancer can be cured if the tumour is completely removed with surgery before cancer cells spread to other organs.
Carcinoma of the gallbladder is very rare affecting just about 4,000 people in the United States every year. For unknown reasons, it is twice more common in women than in men and is usually not diagnosed early due to its lack of unique symptoms and because the gallbladder is hidden behind the liver.
Causes of Condition
Gallbladder cancer occurs when cells in the gallbladder undergo changes that cause them to grow uncontrollably instead of undergoing apoptosis, a process in which they eventually die and replaced with new cells. As a result, a malignant tumour forms. The exact reason why this occurs remains unknown.
Although gallbladder cancer causes are yet to be established, factors listed below are known to increase a person’s risk of developing the disease:
Gallstones - Hardened deposits of digestive fluid that form in the gallbladder or bile duct. As many as 90% of gallbladder cancer patients have gallstones. However, only about 1% of patients with gallstones develop gallbladder cancer.
Gallbladder polyps - Benign or malignant growths in the gallbladder that form when mucous membrane tissue, which the body normally sheds, accumulates in the gallbladder.
Age - Most patients diagnosed with the condition are older than 70. However, the condition can affect any person of any age.
Gender - 7 out of 10 gallbladder cancer patients are women.
A family history of gallbladder cancer - People who have close family members with gallbladder cancer have a slightly increased risk of the disease.
Gallbladder cancer symptoms are very similar to those produced by other medical conditions that affect the digestive system such as ulcerative colitis and inflammatory bowel diseases. Due to the lack of unique signs and symptoms, the condition is often misdiagnosed or found when it is already in its advanced stages.
Patients with gallbladder cancer may experience the following depending on the stage of the disease:
Loss of appetite resulting in unintended weight loss
Lumps in the abdomen
Yellowing of the skin and whites of the eyes
Who to See and Types of Treatments Available
Patients showing symptoms listed above should consult a general practitioner or their family doctor for initial tests and assessment. If carcinoma of the gallbladder is suspected, they will be referred to cancer specialists.
Cancer of the gallbladder is diagnosed with blood tests that measure certain substances released by the liver and imaging tests that create pictures of the gallbladder, such as computerised tomography (CT) scan, ultrasound, and magnetic resonance imaging (MRI).
If the disease is confirmed, doctors proceed with gallbladder cancer staging to determine the extent of cancer spread. In order to do this, some or all of the following tests may be carried out:
Exploratory surgery - Performed by making an incision in the abdomen to look for signs of cancer spread.
Laparoscopy - A procedure that checks organs surrounding the gallbladder using a laparoscope, a lighted tube that is inserted through a cut in the abdomen.
Magnetic resonance cholangiography
Percutaneous transhepatic cholangiography - A procedure that identifies any blockage that may be caused by abnormal growths. For this test, a dye is injected into the bile ducts or liver before the patient undergoes an x-ray.
Computed tomography (CT) of the chest and abdomen
Ultrasonography of the liver
Positron emission tomography (PET) scan
The main goal of gallbladder cancer treatment is to remove the entire tumour and ensure that no cancer cells are left in the body. Unfortunately, this is not possible in many cases especially when abnormal cells have already spread to other surrounding organs and distant body parts before the patient is diagnosed.
Stage I gallbladder cancer (localised malignant tumour) is often treated with cholecystectomy in which the entire gallbladder is removed. Without the gallbladder, the bile will flow from the liver to the small intestine through the common bile duct. Although the body will no longer be able to store bile between meals, this usually does not result in digestion problems.
If cancer has spread to the liver and bile ducts, the affected parts of the said organs are also removed. Surgery is often followed by chemotherapy and/or radiation therapy.
Gallbladder cancer that has already spread to distant body parts cannot be treated with any surgical procedure. In such cases, treatment, which usually combines chemotherapy and radiation therapy, focuses on relieving symptoms with the goal to make patient’s life as comfortable as possible.
Gallbladder cancer prognosis or the patient’s chances of cure are affected by many factors including the stage or severity of the condition, the patient’s overall health, the possible side effects of treatment, and the patient’s preferences.
The five-year survival rate for stage I gallbladder cancer is 50% and the number goes down to only about 4-10% when cancer has already spread.
Feldman M, et al. Sleisenger & Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2010. http://www.clinicalkey.com.
Ferreccio, C. (2012). "Salmonella typhi and Gallbladder Cancer". Bacteria and Cancer. p. 117. ISBN 978-94-007-2584-3. doi:10.1007/978-94-007-2585-0_5