Bladder Cancer Basics
Other rare types of bladder cancer include small cell carcinoma, leiomyosarcoma, lymphoma and melanoma. Cancer can also spread to the bladder from other organs, most often from the prostate, rectum, ovaries, uterus or cervix. Treatment for these rare cancers is quite different than that used for the more common urothelial cancers and can sometimes include removal of the bladder.
Superficial Urothelial Carcinoma
Urothelial cells are also known as transitional cells because of their ability to expand when the bladder is full. They line the inside of the bladder. When urothelial carcinoma invades these cells but doesn't go deeper into the bladder muscle, it's known as superficial urothelial carcinoma. Approximately 90 percent of bladder cancers are urothelial carcinoma, and 70 percent of those are superficial urothelial carcinoma.
When the tumors take the form of mushroom-shaped growths on the bladder lining, surgeons can typically remove them easily. When bladder cancer is diagnosed at this early, superficial stage, it is typically easy to treat. However, most superficial urothelial carcinomas consist of cells that grow very aggressively. This type of bladder cancer has a 70 percent chance of recurrence, and up to 8 percent of superficial urothelial carcinomas move past the first stage to become invasive.
Muscle Invasive Urothelial Carcinoma
Once urothelial carcinoma moves past an early stage, it sometimes invades the bladder muscles. At this stage, there is a risk that the cancer could move out of the bladder and into the bone, liver or lungs, so it must be treated very aggressively. About 30 percent of urothelial carcinomas move on to invade the muscle; often the cancer is already at this stage by the time a patient presents himself for treatment.
Squamous Cell Bladder Cancer
Squamous cell cancer begins with flat cells that line the bladder. About 5 percent of bladder cancers are of this type. Squamous cell cancers are more common in developing countries, where they sometimes develop subsequent to an infection by a worm parasite known as bilharzia or schistosomiasis.
Adenocarcinoma begins in the fluids present in the bladder's lining that are responsible for producing mucus. This type of cancer is very rare, with only 1 to 2 percent of bladder cancer patients experiencing it.
While the most common type of bladder cancer is urothelial carcinoma, also known as transitional cell carcinoma, several rarer types of bladder cancer exist as well. Bladder cancer is often diagnosed after blood is spotted in the urine. Smokers are at a higher risk of bladder cancer than the general population, as are those who work with carcinogenic chemicals or who have a history of frequent bladder infections.