Bladder cancer

概述

Bladder cancer is a common type of cancer that begins in the cells of the bladder. The bladder is a hollow muscular organ in your lower abdomen that stores urine.

Bladder cancer most often begins in the cells (urothelial cells) that line the inside of your bladder. Urothelial cells are also found in your kidneys and the tubes (ureters) that connect the kidneys to the bladder. Urothelial cancer can happen in the kidneys and ureters, too, but it's much more common in the bladder.

Most bladder cancers are diagnosed at an early stage, when the cancer is highly treatable. But even early-stage bladder cancers can come back after successful treatment. For this reason, people with bladder cancer typically need follow-up tests for years after treatment to look for bladder cancer that recurs.

症状

Bladder cancer signs and symptoms may include:

• Blood in urine (hematuria), which may cause urine to appear bright red or cola colored, though sometimes the urine appears normal and blood is detected on a lab test
• Frequent urination
• Painful urination
• Back pain

When to see a doctor

If you notice that you have discolored urine and are concerned it may contain blood, make an appointment with your doctor to get it checked. Also make an appointment with your doctor if you have other signs or symptoms that worry you.

病因

Bladder cancer begins when cells in the bladder develop changes (mutations) in their DNA. A cell's DNA contains instructions that tell the cell what to do. The changes tell the cell to multiply rapidly and to go on living when healthy cells would die. The abnormal cells form a tumor that can invade and destroy normal body tissue. In time, the abnormal cells can break away and spread (metastasize) through the body.

Types of bladder cancer

Different types of cells in your bladder can become cancerous. The type of bladder cell where cancer begins determines the type of bladder cancer. Doctors use this information to determine which treatments may work best for you.

Types of bladder cancer include:

• Urothelial carcinoma. Urothelial carcinoma, previously called transitional cell carcinoma, occurs in the cells that line the inside of the bladder. Urothelial cells expand when your bladder is full and contract when your bladder is empty. These same cells line the inside of the ureters and the urethra, and cancers can form in those places as well. Urothelial carcinoma is the most common type of bladder cancer in the United States.
• Squamous cell carcinoma. Squamous cell carcinoma is associated with chronic irritation of the bladder — for instance, from an infection or from long-term use of a urinary catheter. Squamous cell bladder cancer is rare in the United States. It's more common in parts of the world where a certain parasitic infection (schistosomiasis) is a common cause of bladder infections.
• Adenocarcinoma. Adenocarcinoma begins in cells that make up mucus-secreting glands in the bladder. Adenocarcinoma of the bladder is very rare.

Some bladder cancers include more than one type of cell.

风险因素

Factors that may increase bladder cancer risk include:

• Smoking. Smoking cigarettes, cigars or pipes may increase the risk of bladder cancer by causing harmful chemicals to accumulate in the urine. When you smoke, your body processes the chemicals in the smoke and excretes some of them in your urine. These harmful chemicals may damage the lining of your bladder, which can increase your risk of cancer.
• Increasing age. Bladder cancer risk increases as you age. Though it can occur at any age, most people diagnosed with bladder cancer are older than 55.
• Being male. Men are more likely to develop bladder cancer than women are.
• Exposure to certain chemicals. Your kidneys play a key role in filtering harmful chemicals from your bloodstream and moving them into your bladder. Because of this, it's thought that being around certain chemicals may increase the risk of bladder cancer. Chemicals linked to bladder cancer risk include arsenic and chemicals used in the manufacture of dyes, rubber, leather, textiles and paint products.
• Previous cancer treatment. Treatment with the anti-cancer drug cyclophosphamide increases the risk of bladder cancer. People who received radiation treatments aimed at the pelvis for a previous cancer have a higher risk of developing bladder cancer.
• Chronic bladder inflammation. Chronic or repeated urinary infections or inflammations (cystitis), such as might happen with long-term use of a urinary catheter, may increase the risk of a squamous cell bladder cancer. In some areas of the world, squamous cell carcinoma is linked to chronic bladder inflammation caused by the parasitic infection known as schistosomiasis.
• Personal or family history of cancer. If you've had bladder cancer, you're more likely to get it again. If one of your blood relatives — a parent, sibling or child — has a history of bladder cancer, you may have an increased risk of the disease, although it's rare for bladder cancer to run in families. A family history of Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), can increase the risk of cancer in the urinary system, as well as in the colon, uterus, ovaries and other organs.

预防

Although there's no guaranteed way to prevent bladder cancer, you can take steps to help reduce your risk. For instance:

• Don't smoke. If you don't smoke, don't start. If you smoke, talk to your doctor about a plan to help you stop. Support groups, medications and other methods may help you quit.
• Take caution around chemicals. If you work with chemicals, follow all safety instructions to avoid exposure.
• Choose a variety of fruits and vegetables. Choose a diet rich in a variety of colorful fruits and vegetables. The antioxidants in fruits and vegetables may help reduce your risk of cancer.