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.
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.
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.
Symptoms of bladder cancer1,9,10,11
The majority of bladder cancer symptoms are related to urination. The most common one is hematuria - when blood is found in the urine. Blood can appear in varying degrees, from altering the color of the urine completely to only being detectable only by microscope.
Back pain can be a symptom of bladder cancer that has advanced from its original position in the bladder.
Urination habits can also be affected. Bladder cancer can make a person need to urinate more frequently than normal, hesitantly with a "stop and start" flow, or lead to pain or a burning sensation during urination (dysuria).
More advanced bladder cancer can lead to back pain, weight loss, swelling in the feet, bone pain and a complete inability to urinate.
While symptoms of bladder cancer can appear similar to symptoms of other, often less severe diseases such as infections, bladder stones or enlarged prostate, it is important to have symptoms assessed by a health care provider in order to rule out bladder cancer. The earlier bladder cancer is diagnosed, the more likely it is that it will be treatable.
Tests and diagnosis12-14
After a consultation in which the patient's medical history is discussed, and a physical examination conducted, the health care provider may request further testing in order to help make a diagnosis. A number of diagnostic tests can be carried out to establish a diagnosis of bladder cancer.
Routine screening for bladder cancer is not recommended by the US Preventive Services Task Force as there is little evidence that screening would improve long-term health outcomes. Also, screening may create a risk of patients being subject to false positive diagnoses and undergoing unnecessary invasive procedures that themselves pose a risk of harm.1
The doctor can examine the inside of the urethra and the bladder using a cystoscope; a narrow tube that contains a camera and lighting system that is inserted into the bladder through the urethra.
The doctor can examine the inside of the urethra and the bladder using a cystoscope; a narrow tube that contains a camera and lighting system that is inserted into the bladder through the urethra. The cystoscope is also able to collect cell samples for testing (a biopsy).
Cystoscopies are usually carried out under local anesthetic, but can be carried out under general anesthetic if necessary. If performed under local anesthetic, the cystoscopy can be carried out in a doctor's office; cystoscopy performed under general anesthesia will need to take place in an operating theater.
In addition to supporting a diagnosis of cancer, the following imaging tests can reveal how far the cancer has spread within the body, if at all:
- Pyelogram: contrast dye is injected into the bladder, either by injecting into a vein (intravenous pyelogram) or directly, by using a direct catheter (retrograde pyelogram). The dye outlines the bladder and associated organs, making tumors visible on X-rays
- Computerized tomography (CT): specialized X-rays help determine the shape, size and position of any tumors that might be in the bladder, kidney, or ureters
- Ultrasound: sonography can be used to determine the size of any tumors present as well as whether the cancer has spread beyond the bladder to nearby tissues or organs.
A patient's urine can be examined through various tests:
- Urine cytology: the sample is examined for cancer cells. A negative result does not always guarantee that there is no cancer present
- Urine culture: the sample of urine is placed in a growth medium and monitored for signs of bacterial growth. The bacteria can then be identified and the patient may be diagnosed with an infection rather than cancer
- Urine tumor marker tests: the sample is examined for specific substances that are released by bladder cancer cells. These tests are often carried out alongside urine cytology.
As mentioned above, bladder biopsy samples can be retrieved during a cystoscopy examination. If cancer is present, a biopsy can establish the grade of the cancer and its invasiveness.
Once a diagnosis of bladder cancer has been made, doctors will usually request additional testing in order to determine the extent of the cancer. This is referred to as staging. Additional tests that doctors may order to determine the stage of the cancer include CT scans, chest X-rays, bone scans and magnetic resonance imaging (MRI).
Doctors will examine three specific things when staging a cancer: how far the main tumor has grown through the bladder wall, whether it has spread to distant sites in the body (such as other organs) and whether it has spread to nearby lymph nodes. Lymph nodes are small collections of immune system cells that are often the first cells into which cancers spread.
There are five stages of bladder cancer:
- Stage 0: cancer cells are only found on the outer surface of the inner lining of the bladder. This can be referred to as "carcinoma in situ"
- Stage I: cancer occurs within the inner lining, but has not invaded the lamina propria or muscular wall
- Stage II: cancer has invaded the muscular wall but has not spread from the bladder
- Stage III: cancer has spread through the wall to the tissue surrounding the bladder, including potentially the prostate, uterus or vagina
- Stage IV: cancer has spread to other sites in the body, such as the lymph nodes, bones or other organs such as the lungs or liver.
Individuals who have had bladder cancer in the past are at high risk of recurrence, but researchers publishing in the journal Clinical Cancer Research say a simple DNA methylation marker test in urine can predict tumor recurrence.
Researchers in the UK have developed a device that can help diagnose the early stages of bladder cancer by "sniffing" the gas emitted from urine.
Treatments for bladder cancer16,17,18
There are four main forms of treatment for bladder cancer: surgery, chemotherapy, biological therapy, and radiation therapy. In many cases, a combination of these forms of treatment will be used. The recommended course of treatment will depend on the staging of the cancer, along with the patient's overall health, age, preferences and support system.
Surgery is the most common form of treatment for bladder cancer, with surgical options available for all stages of the disease.
A transurethral resection (TUR) is a procedure that can treat stage 0 and stage 1 bladder cancer. A cutting tool is inserted into the bladder using a type of cystoscope called a resectoscope. This tool can be used to remove small tumors and abnormal tissue and to burn away any remaining cancerous cells.
If the cancer is larger or has spread deeper into the bladder, a form of cystectomy can be carried out. A partial cystectomy is the removal of a portion of the bladder that contains cancer cells.
A radical cystectomy is the removal of the entire bladder, and usually involves the removal of surrounding lymph nodes, the prostate and seminal vesicles, and/or the uterus, ovaries and part of the vagina.
Reconstructive surgery will be carried out after a radical cystectomy to create a new way for the body to store and remove urine, often using a piece of the intestine to create a:
- Urinary conduit: a tube made from part of the intestine to take the urine from the kidneys to a pouch (urostomy bag) on the outside of the body
- Cutaneous continent urinary diversion: a small reservoir for urine made from part of the intestine, which can be drained through a hole in the abdomen using a catheter
- Neobladder: a reservoir made from a part of the intestine that is attached to the urethra, allowing normal urination. A catheter may be required to fully drain the neobladder.
Chemotherapy involves the use of drugs to kill cancer cells or to shrink tumors so that they can be operated on with less invasive surgery. It can be used to treat cancer before or after surgery, and the drugs can be administered orally, intravenously or into the bladder with a catheter (following a TUR).
Chemotherapy is normally given in cycles, with every period of treatment followed by a period of rest to allow the body time to recover.
The drugs used in chemotherapy work against cancer cells because they target cells that divide quickly.
Chemotherapy is a method of using drugs to kill cancer cells, or to shrink tumors so that they can be operated on with less invasive surgery.
Unfortunately, there are other cells within the body which divide quickly which can be affected by the drugs, leading to several side effects:
- Constipation or diarrhea
- Increased bleeding or bruising
- Increased risk of infection
- Loss of appetite
- Loss of hair
- Mouth sores
- Nausea and vomiting.
Chemotherapy side effects depend on the amount of drugs that are taken and how they are taken. If the drugs are administered to the bladder, the side effects are usually milder than in other scenarios. Side effects normally subside once a course of treatment has finished.
Early stages of cancer can be treated by encouraging the immune system to fight the cancer cells, this is known as biological therapy or immunotherapy.
The most common form of biological therapy is Bacillus Calmette-Guerin therapy (BCG). This bacterium is related to the bacterium that causes tuberculosis; BCG therapy inserts this bacterium into the bladder using a catheter in order to attract and activate immune system cells.
These cells are then able to fight any bladder cancer cells that are present. This treatment is normally given once a week for 6 weeks and is often begun shortly after a TUR has been carried out.
Interferon is another biological therapy option. It is a protein made by the immune system to fight infection, and a synthetic version can be used to fight bladder cancer, sometimes in combination with BCG.
Radiation therapy is another option for treating bladder cancer, but it is used less frequently than other treatments and is usually administered alongside chemotherapy. Radiation therapy can help to kill cancer that has invaded the muscular wall of the bladder, and may be helpful for people who are unable to have surgery.
External beam radiation therapy focuses high-energy radiation from a source outside the body on the cancer. The treatment usually consists of short 30 minute sessions, 5 days a week for several weeks.
Side effects depend on the dose of radiation given and the area targeted by the beams. Symptoms include:
- Bladder symptoms, such as discomfort, frequency or hematuria
- Nausea and vomiting
- Varying degrees of skin irritation in the targeted areas.
Following treatment for bladder cancer, most people will be monitored for recurrence. This is because people who have had bladder cancer have a high risk of developing the disease again. Regular examinations are typically scheduled every 3-6 months.
Sometimes bladder cancer does not go away and, instead, must be treated as a chronic disease. People with this form of bladder cancer will need regular treatment in order to keep the cancer in check.
Robot surgeons are nothing new, and they are not science fiction, though the real-life machines may not be instantly familiar to Star Wars fans. Recently, however, research has questioned whether there is evidence to support robot-assisted surgery. MNT investigate the issue.
Scientists have discovered a way to make significant improvements to a popular cancer cell-killing drug called vinblastine, according to a study published in the journal ACS Medicinal Chemistry Letters.
A study that shows how an antibody drug can make it easier for the immune system to find and destroy cancer cells is hailed as a breakthrough in advanced bladder cancer treatment. The result marks the first major advance in the treatment of advanced bladder cancer for 30 years, note the researchers, who report their findings in the journal Nature.
There is no guaranteed way to prevent bladder cancer, but there are ways to reduce the risk of the disease developing. Not smoking, being careful with chemicals, drinking plenty of water and eating a variety of fruit and vegetables are all ways to lessen the chance of developing bladder cancer.24