The bladder collects urine from the kidneys before expelling it from the body through urination. Bladder cancer develops when the cells in bladder tissue start to divide uncontrollably.
Bladder cancer is the fourth most prevalent cancer in men. It also affects females.
In 2019, the American Cancer Society (ACS) predict that around 80,470 people will receive a diagnosis of bladder cancer and 17,670 will die from it in the United States.
Bladder cancer can be benign or malignant. Malignant bladder cancer may be life threatening, as it can spread quickly. Without treatment, it can damage tissues and organs.
In this article, we cover everything you need to know about bladder cancer, including types, symptoms, causes, and treatments.
Bladder cancer usually starts in the transitional epithelium, which are the cells that line the bladder.
Most bladder cancers are TCC. TCC is also known as urothelial carcinoma.
This type of bladder cancer starts in the cells that line the inside of the bladder. These cells also line other parts of the urinary tract, so TCC can also affect the lining of the kidneys and the ureters.
Anyone with a diagnosis of TCC will usually undergo an assessment of the whole urinary tract.
TCCs can be invasive or noninvasive, depending on whether or not they spread into the lamina propria or muscle layer. Invasive cancers are harder to treat.
Several other types of cancer can start in the bladder, including:
- Squamous cell carcinoma: This type constitutes about 1–2% of bladder cancers. It occurs in the thin, flat cells on the surface of bladder tissue. Most squamous cell cancers are invasive.
- Adenocarcinoma: About 1% of bladder cancers are adenocarcinomas. It occurs in the cells of the bladder glands that secrete mucus. Most bladder adenocarcinomas are invasive.
- Small cell carcinoma: Fewer than 1% of bladder cancers are small cell carcinomas. It starts in the nerve-like cells called neuroendocrine cells. This type often grows quickly and requires treatment with chemotherapy.
- Sarcoma: This is a rare type of bladder cancer that originates in the muscle cells of the bladder.
The main forms of treatment for bladder cancer include one or several of the following:
- biological therapy
- radiation therapy
Treatment will depend on several factors, including:
- the location and stage of the cancer
- the individual’s overall health
- their age
- their personal preferences
Surgical options are available for all stages of the condition:
- A transurethral resection (TUR): A surgeon can treat stage 0 and 1 bladder cancer using this method. They will insert a cutting tool into the bladder to remove small tumors and abnormal tissue. They also burn away any remaining cancerous cells.
- Cystectomy: If the cancer is larger or has spread deeper into the bladder, a surgeon can perform a cystectomy, removing the whole bladder or just the cancerous tissue.
- Reconstructive surgery: Undergoing this procedure after a cystectomy can help provide a new way for the body to store and remove urine. A surgeon can use intestinal tissue to reconstruct the bladder or surrounding tubes.
Chemotherapy uses drugs to target and kill cancer cells or to shrink tumors and allow a surgeon to use a less invasive procedure.
Chemotherapy can also treat cancer before or after surgery. People can take these drugs orally, intravenously, or via injection into the bladder using a catheter (following a TUR).
Treatment for early stage bladder cancer might involve encouraging the immune system to fight cancer cells. This is called biological therapy, or immunotherapy.
The most common form of biological therapy is Bacillus Calmette–Guerin therapy (BCG). A healthcare professional uses a catheter to insert this bacterium into the bladder.
The bacterium attracts and activates immune system cells, which are then able to fight any bladder cancer cells that are present. This treatment usually takes place weekly for 6 weeks, often beginning shortly after a TUR.
Interferon is another biological therapy option. The immune system makes this protein to fight infection, and a synthetic version is able to fight bladder cancer, sometimes in combination with BCG.
In May 2016, the Food and Drug Administration (FDA)
They explained that the injections were only safe and effective when:
- The cancer progressed during or following chemotherapy that contains platinum.
- The cancer progressed within 12 months of neoadjuvant or adjuvant treatment with chemotherapy that contains platinum.
Radiation therapy is a less common intervention for bladder cancer. Doctors may recommend it in combination with chemotherapy.
It can help kill cancer that has invaded the muscular wall of the bladder. It may be helpful for people who cannot have surgery.
Bladder cancer has a high risk of recurrence. Doctors usually recommend regular monitoring after treatment.
Bladder cancer does not always resolve. Instead, it can become a chronic condition. Regular treatment will be necessary to control the cancer.
In the early stages, common symptoms include:
Blood in the urine: This is common. It can range from being detectable through a microscope to altering the color of the urine completely.
Urination habits: A person may need to urinate more often than usual. There may be a “stop and start” flow, or they may experience pain or a burning sensation during urination.
Later stage bladder cancer may cause the following symptoms:
- back pain
- weight loss
- swelling in the feet
- bone pain
- an inability to urinate
The symptoms of bladder cancer can resemble those of a bladder infection. It is important to seek medical advice if symptoms persist.
The cause of bladder cancer remains unknown, but genetic mutations may play a role.
Smoking tobacco and having exposure to chemicals may cause mutations that lead to bladder cancer. However, these may affect people in different ways.
Scientists do not consider genetics to be a major cause of bladder cancer. They do suggest, however, that these factors might make a person more susceptible to the effects of tobacco and certain industrial chemicals.
Scientists have identified certain risk factors for bladder cancer, of which smoking is the most important. People who smoke are at least three times more likely to develop bladder cancer than people who do not smoke.
The risk of bladder cancer also increases with age. Around 90% of people with a diagnosis are over 55 years of age. The average age of diagnosis is 73.
Other risk factors may include:
- congenital anomalies in the bladder
- chemotherapy and radiation therapy
- chronic bladder irritation and infections
- exposure to certain chemicals in the environment, including aromatic amines and arsenic in drinking water
- exposure to some industrial chemicals, such as certain substances that people use in printing, painting, hairdressing, and machine operating
- race, as white people have twice the risk of bladder cancer compared with African American and Hispanic people
- sex, as males have a higher risk than females
- low fluid consumption
- a personal or family history of bladder cancer
Some medications and dietary supplements, such as pioglitazone (Actos) and aristolochic acid, may also increase the risk.
These mainly come from plants in the Aristolochia family, such as birthwort, or Dutchman’s pipe, which people commonly used in traditional medicine.
According to the University of Oxford in the United Kingdom, a toxin in these plants may have links to kidney problems and cancer in the long term.
However, bladder cancer can develop even without these risk factors.
A doctor will ask about symptoms and medical history. They will also conduct a physical examination. Tests, such as the following, can help confirm a diagnosis and staging of bladder cancer.
A doctor can examine the inside of the urethra and bladder by using a cystoscope. A cystoscope is a narrow tube that contains a camera and lighting system.
Cystoscopy usually involves a local anesthetic and takes place in a physician’s office. If the person needs a general anesthetic, the procedure will instead take place in the hospital.
The following imaging tests can help confirm a diagnosis and reveal if the cancer has spread within the body:
- Pyelogram: A healthcare professional will inject a contrast dye into the bladder, either directly into a vein or by using a catheter. The dye outlines the bladder and associated organs, making any tumors visible on an X-ray.
- CT scan: This can help a doctor determine the shape, size, and position of any tumors.
- Ultrasound: A doctor can use an ultrasound to determine the size of any tumors and determine if the cancer has spread beyond the bladder to nearby tissue or organs.
There are several types of urine test:
- Urine cytology: A medical professional will examine the sample for cancer cells. A negative result does not always guarantee that there is no cancer.
- Urine culture: A laboratory technician places the sample in a growth medium and monitors it for signs of bacterial growth. They can then identify the bacteria. This can help a doctor rule out infection rather than cancer.
- Urine tumor marker tests: A laboratory technician examines a sample for specific substances that bladder cancer cells release. These tests often occur alongside urine cytology.
During a cystoscopy, a surgeon can retrieve samples for a bladder biopsy. If cancer is present, a biopsy can help a doctor establish its invasiveness.
A doctor can also use a thin, hollow needle to collect a biopsy, often using a CT scan or ultrasound as guidance.
Additional testing after diagnosis will determine the stage of the cancer.
Staging describes how far the cancer has spread and determines which treatment is the most suitable option.
There are several ways of staging cancer. One method describes five stages:
Stage 0: Cancer cells occur on the outer surface of the inner lining of the bladder. At this stage, bladder cancer would be a noninvasive papillary carcinoma that has developed toward the hollow part of the bladder or an invasive papilloma that has not moved beyond the inner lining of the womb.
Stage I: Cancer occurs within the inner lining of the bladder but has not spread to the lamina propria or muscular wall. It has only reached the connective tissue underneath the bladder lining.
Stage II: Cancer has entered the muscular wall but remains in the bladder only. It has not reached the fatty layer that surrounds the bladder.
Stage III: Cancer has spread through the wall to the tissue surrounding the bladder, including other organs, such as the prostate, uterus, or vagina. This stage has several subtypes depending on the route of the spread. The cancer may also have spread to a lymph node.
Stage IV: Cancer has either spread to distant sites in the body — such as the lymph nodes, bones, or other organs, such as the lungs or liver — or moved into the pelvic wall, abdominal wall, or nearby organs.
The stage at diagnosis will affect a person’s treatment options and outlook.
Avoiding certain lifestyle factors may help a person reduce the risk of bladder cancer.
- not smoking
- being careful around chemicals
- drinking plenty of water
- eating a variety of fruits and vegetables
The ACS note that if a medical professional detects bladder cancer at stage 0, the chance of surviving for at least 5 years after diagnosis is 95%.
If the cancer reaches other parts of the body, the chances of successful treatment are lower. If diagnosis occurs at stage 4, the 5 year survival rate drops to 15%.
Early diagnosis significantly improves the chance of successful treatment, but treatment is possible even in the later stages of bladder cancer.