Bladder cancer

Alternative names:

transitional cell carcinoma of the bladder

Definition:

A malignant tumor growth within the bladder. Bladder cancers usually arise from the transitional cells of the bladder (the cells lining the bladder). These tumors may be classified based on their growth pattern as either papillary tumors (meaning they have a wart-like lesion attached to a stalk) or nonpapillary tumors. Nonpapillary tumors are much less common (10%) but they are more invasive and have a poorer prognosis.

Causes, incidence, and risk factors:

As with most other cancers, the exact cause is uncertain. However, several factors may contribute to the development of bladder cancer. Cigarette smoking has been shown to increase the risk of developing bladder cancer, with smokers having a four-fold increased risk when compared to non-smokers. Also, the risk of developing bladder cancer does show a gradual decline in individuals who quit smoking.

Studies show that one in four cases of bladder cancer can be attributed to industrial exposure to known carcinogens. People at increased risk due to industrial exposure include textile workers, painters, hair-dressers, and people who work with in the leather, metal, or rubber industry.

Some studies indicate that there may be a link between high doses of the artificial sweetener saccharin and transitional cell bladder cancer. Results of these studies has lead to the removal of saccharin from the market.

Current research indicates a weak link between caffeine and bladder cancer; however, the researchers are unable to separate other factors, such as cigarette smoking and saccharin, that may be responsible for the association.

Women who received radiation therapy for the treatment of cervical cancer have a fourfold increased risk of developing transitional cell bladder cancer. Additionally, people who received the chemotherapy drug, cyclophosphamide (Cytoxan) may have a nine times greater risk of developing bladder cancer.

Chronic (long term) bladder infection or irritation may lead to the development of squamous cell bladder cancer, however, this cancer is very slow growing.

Bladder cancer rarely occurs in people under 40 years of age. Bladder cancer occurs more frequently in the United States and England. Also, within the United States, people who live in the northern half of the country have higher rates of bladder cancer than those in the lower states.

Heredity is not a factor in development of bladder cancer, although Jewish people have higher rates of bladder cancer than the rest of the population.

Bladder cancers are classified or staged based on their aggressiveness and the degree that they are different from the surrounding bladder tissue (differentiation). There are several different ways to stage tumors; however, most bladder cancers are staged using the A-B-C-D staging system (also known as the Jewett-Strong-Marshall system). This staging system contains several substages, but it basically categorizes tumors using the following scale:
0 carcinoma in situ (tumor limited to the bladder mucosa (lining)
A tumor extends through the mucosa but does not extend beyond submucosa
B tumor invades the muscle
C invade through the fat
D cancer has spread to regional lymph nodes or to distant sites

Bladder cancers spreads by extending into the nearby organs, including the prostate, uterus, vagina, ureters, and rectum. Metastasis occurs through the pelvic lymph nodes, where the tumor next spreads to the liver, lungs and bones.