Transitional Cell Carcinoma Health Article

Definition

Transitional cell carcinoma is a type of cancer that originates in the kidney, bladder, or ureter (the tube that carries urine from the kidney to the bladder).

Description

A transitional cell is intermediate between the flat squamous cell and the tall columnar cell. It is restricted to the epithelium (cellular lining) of the urinary bladder, ureters (tubes that carry urine from the kidneys to the bladder), and the pelvis of the kidney (that portion of the kidney collecting the urine as it leaves the kidneys and enters the ureters). Transitional cell carcinomas have a wide range in their gross appearance depending on their locations. Some of these carcinomas are flat in appearance, some are papillary (small elevation), and others are in the shape of a node. Under the microscope, however, most of these carcinomas have a papillary-like look. There are three generally recognized grades of transitional cell carcinoma. The grade of the carcinoma is determined by particular characteristics found in the cells of the tumor. Transitional cell carcinoma typically affects the mucosa (the moist tissue layer that lines hollow organs or the cavity of the body) in the areas where it originates.

The most common site of transitional cell carcinoma is in the urinary bladder. Transitional cell carcinoma is the form of cancer in about 90% of cancers found in the bladder. The highest grade of transitional cell carcinoma is very likely to spread to other parts of the body. There are two primary ways that transitional cell carcinoma spreads into the surrounding structures. The first is by way of epithelial cells that line the body cavity and many of the passageways that exit the body. The other means of spread is through the lymphatic (network that resembles the circulatory system but transports proteins, salts, water, and other substances) system.

Demographics

Most patients who develop transitional cell carcinoma are older than 40 years of age. Males are about three times more likely than females to develop this type of carcinoma. About 93% of all bladder cancers in North American are of the transitional cell carcinoma type. Only 8% of all renal cancers are of the transitional cell carcinoma type.

Causes and symptoms

The causes and mechanisms of transitional cell carcinoma, like all forms of cancer, are not entirely known or understood. However, researchers have isolated several factors that have been associated with an increased risk for developing this carcinoma.

Cigarette smoking is the strongest risk factor for transitional cell carcinoma. Researchers have found smoking increases the risk for developing this condition by three to seven times. In men with bladder cancer, 50% to 80% have a history of smoking cigarettes. Other methods of using tobacco, such as cigar and pipe smoking and chewing tobacco, have been shown to increase the risk of developing this carcinoma but at a reduced rate compared with smoking.

Individuals who have undergone long-term exposure to industrial chemicals, such as the class of compounds known as arylamines, are known to have an increased risk of developing transitional cell carcinoma. One of the most dangerous of these chemicals is one known as 2-naphthylamine. Individuals who develop these carcinomas usually do so anywhere from 15 to 40 years following the first exposure to these chemicals.

Individuals who have used analgesics for many years, or have used them excessively in the short-term, are at an increased risk for developing transitional cell carcinoma. Many of these patients have suffered at least some damage to the kidneys before developing the carcinoma. Drugs given to patients to treat an earlier cancer, such as the commonly used cyclophosphamide, increase the risk of developing transitional cell carcinoma at a later time.

Researchers believe these factors somehow alter genes that are important in the development of transitional cell carcinoma. These changes most often involve the deletions of certain chromosomes but also may result from mutations.

The most common symptom of transitional cell carcinoma is blood in the urine without accompanying pain. There may also be changes in the urge for the patient to urinate and in the frequency of urination. In some cases, urine may be partially obstructed by a tumor in the ureter. Rarely, pain occurs in the pelvic region. Physicians rarely detect a tumorous mass by touch during the first examination.