In short
Bladder cancer is a disease that begins when cells in the bladder start growing out of control, forming tumors in the tissue that lines this small, hollow organ responsible for storing urine. Most cases are caught relatively early and can be treated, but the disease has a frustrating tendency to return even after successful treatment, requiring patients to remain watchful and undergo regular check-ups for many years.
Key points
- Bladder cancer is the sixth most common cancer in the U.S., with about 82,000 new cases diagnosed annually, and men are four times more likely to develop it than women.
- Smoking is the single biggest risk factor, causing about half of all bladder cancers, and smokers face three times the risk of non-smokers.
- Blood in the urine is the most common symptom that sends people to seek medical care, though other symptoms like frequent or painful urination are also warning signs.
- Most bladder cancers are caught early before they spread into the muscle, but about 75% of these early-stage cancers return after treatment, requiring ongoing monitoring.
- More than 90% of bladder cancers are urothelial carcinoma, which starts in the special stretchy cells lining the inside of the bladder.
- Drinking plenty of water, eating fruits and vegetables, exercising regularly, and never smoking (or quitting if you do) can help reduce your risk of bladder cancer.
- The five-year survival rate for bladder cancer caught in its earliest stage is 96%, highlighting the critical importance of early detection.
- Women with bladder cancer are often diagnosed at more advanced stages because they may dismiss symptoms as urinary tract infections or other common conditions.
Understanding How Common Bladder Cancer Is
Bladder cancer ranks as the sixth most common cancer in the United States, with approximately 82,000 new cases diagnosed each year and around 17,000 deaths annually. Worldwide, it stands as the ninth most common cancer, with an estimated 550,000 new cases and 200,000 deaths globally in 2017. This disease predominantly affects older adults, with most diagnoses occurring in people over the age of 55.
The disease shows a striking gender difference, affecting men far more frequently than women. Men are approximately four times more likely to develop bladder cancer than women, accounting for about 75% of new cases and deaths. The reasons behind this gender gap remain unclear to researchers. However, when women do develop bladder cancer, they often face a more challenging situation because their disease is typically diagnosed at more advanced stages, partly because they may not recognize or pay attention to early warning signs like blood in the urine.
Bladder cancer is particularly notable as the fourth most common cancer specifically in males. In industrialized nations, a specific type called urothelial carcinoma (also known as transitional cell carcinoma) makes up more than 90% of all bladder cancer cases.
What Causes Bladder Cancer
Bladder cancer occurs when cells in the tissue lining the bladder undergo changes that cause them to become abnormal. These cells then multiply uncontrollably and form tumors. The bladder is lined with a special tissue called urothelium, which is made of cells that can stretch when the bladder fills with urine and shrink when it empties. Most bladder cancers start in these urothelial cells.
While researchers understand the basic process of how bladder cancer develops, the exact reasons why certain individuals develop these cellular changes remain complex. The disease appears to result from a combination of genetic factors and environmental exposures that damage the bladder cells over time. As these damaged cells accumulate and continue to multiply, they can eventually form tumors that, if left untreated, may grow through the bladder wall and spread to other parts of the body, including nearby lymph nodes, bones, lungs, or liver.
Risk Factors That Increase Your Chances
Smoking stands out as the single most significant risk factor for bladder cancer. It is thought to be the cause of about half of all bladder cancers. Smokers face three times the risk of developing bladder cancer compared to non-smokers. This heightened risk occurs because as the bladder filters the harmful chemicals ingested through cigarette smoke, the organ's lining becomes damaged over time.
Age represents another major risk factor, with people over 55 years old facing considerably higher odds of developing the disease. Exposure to harmful chemicals, whether at home or in the workplace, also increases risk. Workers in certain industries where they come into contact with specific chemicals may be more vulnerable to developing bladder cancer.
Previous cancer treatments can elevate risk as well. Individuals who have undergone certain cancer therapies may find themselves at higher risk for bladder cancer later in life. Chronic bladder inflammation is another contributing factor. People who experience long-term irritation or infection of the bladder, including those with chronic bladder conditions, face increased risk.
A family history of bladder cancer can also play a role, suggesting that genetic factors may make some people more susceptible to the disease. Additionally, men are at significantly higher risk than women, though the reasons for this gender difference are not entirely clear.
Recognizing the Symptoms
The symptoms of bladder cancer are usually clear and relatively easy to notice, which is why many cases are caught in the early stages. The most common warning sign is blood in the urine, which may be visible to the naked eye or only detectable under a microscope during testing. This symptom, called hematuria, sends most people with bladder cancer to seek medical advice.
Other symptoms include frequent urination, where a person feels the need to urinate more often than usual. Painful urination is another common complaint, where passing urine causes discomfort or a burning sensation. Some people experience back pain or unexplained pelvic pain. These symptoms can sometimes be mistaken for other less serious conditions, such as urinary tract infections or kidney stones, which is why proper medical evaluation is important.
How to Reduce Your Risk
While it is not possible to prevent bladder cancer entirely, there are several steps you can take to lower your risk. The most important action is to quit smoking if you smoke, or never start if you don't. Since smoking is responsible for about half of all bladder cancer cases, avoiding tobacco can dramatically reduce your chances of developing the disease.
Staying well hydrated by drinking plenty of fluids, particularly water, may help lower your risk of developing bladder cancer. Aim to drink six to eight glasses of water each day. The theory is that drinking more water helps dilute any potentially harmful substances in your urine and ensures they are flushed out of your bladder more quickly.
Following a healthy diet rich in fruits and vegetables may help keep your bladder healthy and reduce cancer risk. A nutrient-rich diet also lowers the risk of developing other types of cancers. Try to eat at least five servings of fruits and vegetables every day, along with whole grains.
Regular physical activity is another important preventive measure. Exercise not only helps reduce the risk of cancer recurrence for those who have been treated but also supports overall health and well-being. Even just 30 minutes of moderate exercise daily can make a difference. If you work with chemicals or in an environment where you might be exposed to harmful substances, following proper safety procedures and wearing protective equipment can help reduce your risk.
How the Disease Affects the Body
To understand how bladder cancer affects the body, it helps to know how the bladder normally works. The bladder is a triangle-shaped, hollow organ located in the lower part of the abdomen, centered between the hip bones, above the urethra and below the kidneys. It has a muscular wall that allows it to expand to store urine made by the kidneys and then contract to squeeze urine out of the body. A healthy bladder can hold about two cups of urine.
The kidneys work together with the bladder to remove toxins and wastes from the body through urine. Tiny tubules in the kidneys filter and clean the blood, taking out waste products and making urine. This urine then passes from each kidney through long tubes called ureters into the bladder, where it is stored until it passes through another tube called the urethra and leaves the body.
When bladder cancer develops, abnormal cells multiply in the lining of the bladder and form tumors. If these tumors are not treated, they can grow in several ways. Some remain on or near the surface of the bladder lining, which is considered noninvasive bladder cancer. Others may move deeper into the bladder but not reach the muscle, which is called non-muscle-invasive bladder cancer. The most concerning type is muscle-invasive bladder cancer, where the cancer has grown into the bladder wall muscle and may have spread into the fatty layers or tissues outside the bladder.
Most bladder cancers are non-muscle-invasive when first diagnosed. However, even these early-stage cancers can be troublesome because they have a high tendency to come back after treatment. About 75% of early-stage bladder cancers recur, which is why people with bladder cancer need to undergo regular follow-up examinations for many years.
If bladder cancer progresses without treatment, it can spread beyond the bladder walls to nearby lymph nodes and then to other areas of the body, including the bones, lungs, or liver. This process is called metastasis. When cancer spreads to distant parts of the body, it becomes much more difficult to treat and the outlook becomes less favorable.
