How to understand bladder cancer

Bladder cancer is a malignant overgrowth of cells in the bladder. The most common overgrowth is in the lining of the bladder. The surface of hollow organs in the human body is usually made up of epithelial cells. For example, the inside of your cheeks, stomach, intestines, gallbladder, and bladder are all made up of a layer of epithelial cells. Each organ has its own type of epithelial cells. The epithelial cells in the bladder are called urothelial cells, and the cancer that develops from them is called urothelial carcinoma, which accounts for 90 to 95 percent of all bladder cancers.

Other less common types of bladder cancer are squamous cell carcinoma and adenocarcinoma. A very rare type of bladder cancer in children is called rhabdomyosarcoma.

Cancer cells that spread to the bladder from other parts of the body are called bladder metastases. This is rare, but they can occasionally grow into the bladder from nearby organs, such as the prostate, colon, rectum, or cervix. All malignancies, including bladder cancer, occur because of changes in the DNA of normal cells.

Chemical exposures can damage the DNA of normal cells, such as smoking, industrial chemicals, and chemotherapy. These environmental exposures are called risk factors. Risk factors do not directly cause bladder cancer, just as not every smoker will get bladder cancer. However, from a population perspective, smokers have an increased risk of cancer compared to non-smokers. Exposure to these factors can increase the chance of DNA damage. When specific DNA that controls cell growth is damaged, normal cells may become cancer cells. The characteristic of cancer is the excessive growth of cells that push and destroy surrounding normal tissue.