Gallbladder cancer is a relatively rare cancer that affects the tissues of the gallbladder -the organ that stores bile that enables the liver to digest fat. Primary gallbladder cancer starts in the inner layer and spreads through the outer layers as it grows. If detected early, it is often cured. If undetected, however, it often spreads and can be very dangerous. Treatment options for gallbladder cancer depend on the stage of cancer. In the early stages the gallbladder is often removed by itself or with a small part of the liver. The later stages require treatments such as chemotherapy and radiation.