The gallbladder is a pear-shaped organ which lies in the upper abdomen, just below the liver. The primary function of the gallbladder is to store bile – a digestive liquid formed by the liver to digest fat. The gallbladder releases this bile when the food particles are being digested in the stomach and intestines. Gallbladder cancer is a rather uncommon form of cancer in which malignant cancerous cells are formed in the tissues of the walls of the gallbladder. This form of cancer is almost five times more common in women than in men. It mostly affects the people in the age groups of 50 and 60 years.

The wall of the gallbladder comprises of 3 key layers of tissues. They are: mucosal layer (innermost layer), muscularis layer (middle muscular layer) and serosal layer (outermost layer). Sandwiched between these three layers is a connecting tissue. Gallbladder cancer starts in the innermost layer and grows towards the outer layers as it develops. There are four major stages of gallbladder cancer – stages 1 to 4. Some doctors also consider a stage 0.

Stage 0 or Carcinoma-in-situ (CIS):

This is a very, very early stage of the cancer. In this stage, the cancer cells are there only in the layer of the tissue lining the gallbladder. Some doctors do not consider this as a real stage of cancer as the cancer cells are present only in the lining. It is almost impossible to diagnose gallbladder cancer at this stage, as there are very little or no symptoms visible.

Stage 1:

This is the earliest stage of gallbladder cancer. In this stage, the cancerous cells are present only in the inner layers of the tissues which line the gallbladder and they haven’t yet spread to nearby tissues or organs.

Stage 2:

In this stage, the cancer grows through the muscular layer of the wall of the gallbladder into the connective tissue beneath it.

Stage 3:

This stage has 2 parts- 3A and 3B. In stage 3A, the cancerous cells grow throughout the gallbladder wall, but do not spread to the surrounding lymph nodes. In stage 3B, the cancerous cells break through the outer lining of the gallbladder walls and spread to the surrounding lymph nodes.

Stage 4:

This is the advanced stage. It is also divided into parts- 4A and 4B. In stage 4A, the cancer grows either into any one of the main blood vessels going into the liver or into 2 or more organs outside the liver. In stage 4B, the cancer grows to any size and spreads further away from the gallbladder. It may or may not spread to other organs in the body.

The various treatment options for gallbladder cancer include radiation, chemotherapy, surgery or a grouping of these. The most effective treatment is the surgical removal of the gallbladder.