In 2004, bladder cancer was the 4th most prevalent cancer in men and the 11th most prevalent cancer in women.1
For 2015, the American Cancer Society estimates that there will be around 74,000 new cases diagnosed and 16,000 deaths from bladder cancer. Of these, 72% will be men.2
The National Cancer Institute (NCI) define cancer as "a term for diseases in which abnormal cells divide without control and can invade nearby tissues."3 Cancer can affect all organs of the body, including the bladder - the organ that collects urine from the kidneys prior to its elimination from the body through urination.
The abnormal cells may form into a mass called a tumor, which can be either benign or malignant. Malignant tumors can be a severe threat to a person's health and can grow back even after removal. As well as damaging nearby tissues and organs, they are also able to spread to other parts of the body.4
Contents of this article:
You will also see introductions at the end of some sections to any recent developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Fast facts on bladder cancer
Here are some key points about bladder cancer. More detail and supporting information is in the main article.
- Around nine out of 10 people diagnosed with bladder cancer are aged over 55.
- Smokers are around three times more likely to develop bladder cancer than non-smokers.
- The most common symptom of bladder cancer is hematuria.
- Bladder cancer shares many of symptoms with other less severe illnesses, such as bladder infections.
- The US Preventive Services Task Force advises against routine screening to diagnose bladder cancer.
- Bladder cancer is often diagnosed using imaging tests and cystoscopies.
- There are five different stages in severity for bladder cancer, with about 50% of cases diagnosed in the early non-invasive stage, and 35% diagnosed while the cancer is still contained in the bladder.
- In about 4% of cases, diagnosis is made after cancer originating in the bladder has spread to distant tissues.
- Bladder cancer can be treated with surgery, drugs and radiation therapy.
- People who develop bladder cancer are at a high risk of developing the disease for a second time.
- Although there is no guaranteed way to prevent bladder cancer, there are many ways to reduce the risk of it developing.
What is bladder cancer?2,5,6
Bladder cancer is a form of cancer that commonly begins in the cells lining the bladder, also known as transitional epithelium.
As with all cancers, it can develop into a life-threatening illness - though most cases of bladder cancer (about 50%) are diagnosed at an early stage when the disease is highly treatable.
Hematuria is the most common symptom of bladder cancer. Some cases of bladder cancer can only be detected through urine testing.
Bladder cancer is most commonly found in older people, with people over 55 making up about 90% of diagnosed cases. The average age at which bladder cancer is diagnosed is 73 years.
Men are around 3-4 times more likely to develop bladder cancer than women, and the chances of a man getting bladder cancer in his life are 1 in 26 (1 in 90 for women).
White people are diagnosed with bladder cancer almost twice as often as black people, however black people are more likely to have an advanced form of the cancer by the time they are diagnosed.
The most common type of bladder cancer is transitional cell carcinoma (TCC). This form accounts for around 90% of bladder cancers and originates in the urothelial cells that line the inside of the bladder. These cells also line other parts of the urinary tract, meaning that TCC can also arise in the lining of the kidneys, ureters and the ureters. As such, anyone diagnosed with this type of bladder cancer will usually have the rest of their urinary tract assessed for tumors.
TCCs are classified as invasive and non-invasive, depending on whether they remain in the epithelium (lining) of the bladder, or have spread deeper into the lamina propria or muscle layer. The more invasive the cancer, the harder it is to treat.
TCCs are further divided into two types:
- Papillary carcinomas - these grow in thin projections from the inner surface of the bladder toward the hollow center. They are non-invasive papillary cancers, and very low-grade, non-invasive types tend to have a very good outcome as they have a low likelihood of malignancy.
- Flat carcinomas - these do not grow toward the hollow part of the bladder, and are known as a non-invasive flat carcinoma or a flat carcinoma in situ (CIS) if they remain in the inner layer of bladder cells.
There are several other types of cancer that can originate in the bladder, all of which are much less common than transitional cell (urothelial) cancer. These include:
- Squamous cell carcinoma: This form accounts for about 1-2% of bladder cancers. It arises in the squamous cells, which are thin, flat cells like those that make up the surface of the skin. Almost all squamous cell cancers are invasive.
- Adenocarcinoma: This form accounts for about 1% of bladder cancers. It occurs in the cells of the mucus-secreting glands found in the bladder and has similarities to colon cancer. Almost all adenocarcinomas of the bladder are invasive.
- Small cell carcinoma: This form accounts for less than 1% of bladder cancers. It arises in the nerve-like cells called neuroendocrine cells. This form often grows quickly and requires treatment with chemotherapy (as with small cell carcinoma of the lung).
- Sarcoma: This is a rare form of bladder cancer that originates in the muscle cells of the bladder.
Causes of bladder cancer7,8
The cause of bladder cancer remains unknown, although certain risk factors for the disease have been identified. Smoking is the most important risk factor, with smokers at least three times more likely to develop bladder cancer than non-smokers.
Bladder cancer risk factors include:
- Bladder defects from birth
- Chemotherapy and radiation therapy
- Chronic bladder infections and irritations
- Exposure to certain chemicals including aromatic amines
- Low fluid consumption
- Personal or family history of bladder cancer
- Being male and/or white (women have lower rates of bladder cancer, as do African-Americans, Hispanics, Asian-Americans, and Native Americans
- Some medications and dietary supplements - pioglitazone (Actos) and aristolochic acid (mainly from plants in the Aristolochia family)
- Exposure to arsenic in drinking water (not normally a problem in the US).
Exposure to these risk factors does not guarantee that bladder cancer will develop. Likewise, bladder cancer can still develop in the absence of all of these risk factors. They have merely been found to increase the chances of the disease occurring.
People who work in the following industries or who have the following professions also have an increased risk of bladder cancer, likely due to exposure to certain chemicals:
- Manufacturing of rubber, leather, textiles and paint products
- Truck drivers.
Those who smoke and work in one of these industries have an especially high risk of bladder cancer as the carcinogenic effects are often compounded.
Recent developments on bladder cancer causes from MNT news
A new study in Occupational & Environmental Medicine has linked the frequency of dye and perm use to raised levels of carcinogens found in hairdressers' blood.
According to the Centers for Disease Control and Prevention, smoking can cause cancer almost anywhere in the body. It is also known to decrease the effectiveness of cancer treatments, reduce survival time and increase the probability of recurrence. Despite all this, a new study has found that smoking habits can continue long after a cancer diagnosis has been made.
On the next page we look at the symptoms of bladder cancer and how it is diagnosed. On the final page we discuss the available treatments for bladder cancer.