All about bladder cancer
Bladder cancer is the fourth most prevalent cancer in men. Men have a 1 in 27 chance of developing it. Women have a 1 in 89 chance of getting it. The numbers of cases affecting men have been stable in recent years, but those affecting women have fallen.
In 2018, the American Cancer Society expects that there will be around 81,190 new cases and 17,240 deaths from bladder cancer. Of these, 72 percent will be men.
Bladder cancer happens when abnormal cells develop in the bladder. They can be benign or malignant. Malignant cancers can be life-threatening as they can spread quickly. Untreated, they can damage tissues and organs and spread to other parts of the body.
Advances in science and medicine, however, mean that effective treatment is possible, especially if a diagnosis occurs in the early stages.
Here are some key points about bladder cancer. More detail is in the main article.
- Around 90 percent of people who receive a diagnosis of bladder cancer are aged over 55 years.
- Smokers are around three times more likely to develop bladder cancer than non-smokers.
- Symptoms may be similar to those of less severe illnesses, such as a bladder infection.
- Half of all cases are found when the cancer is still only in the bladder, but 4 percent of diagnoses are made after bladder cancer has spread to distant tissues.
- Treatment includes surgery, chemotherapy, immunotherapy, and radiation therapy, alone or in combination.
- Some lifestyle factors can reduce the risk of developing bladder cancer.
What is bladder cancer?
Blood in the urine is the most common symptom of bladder cancer.
Bladder cancer usually starts in the transitional epithelium, the cells that line the bladder.
Around half of all cases are diagnosed at an early stage, when the cancer is highly treatable. Without treatment, however, it can be life-threatening.
The risk of bladder cancer increases with age, and around 90 percent of people who receive a diagnosis are aged over 55 years. The average age at diagnosis is 73 years.
Transitional cell carcinoma
Most bladder cancers are transitional cell carcinoma (TCC). This form starts in the urothelial cells, which line the inside of the bladder.
These cells also line other parts of the urinary tract, so TCC can also occur in the lining of the kidneys and the ureters, too. Anyone who receives a diagnosis of TCC will usually undergo an assessment of the whole urinary tract.
TCCs can be invasive or non-invasive, depending on whether they remain in the lining of the bladder, known as the epithelium, or if they 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. 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. If they remain in the inner layer of bladder cells, they are known as a non-invasive flat carcinoma or a flat carcinoma in situ (CIS).
Several other types of cancer that can start in the bladder. They are all much less common than TCC.
- Squamous cell carcinoma: About 1 to 2 percent of bladder cancers are of this type. It occurs in the squamous cells, the thin, flat cells like those that make up the surface of the skin. Most squamous cell cancers are invasive.
- Adenocarcinoma: About 1 percent of bladder cancers are of this time. It occurs in the cells of the mucus-secreting glands found in the bladder. It has similarities to colon cancer. Most adenocarcinomas of the bladder are invasive.
- Small cell carcinoma: Fewer than 1 percent of bladder cancers are of this type. It starts in the nerve-like cells called neuroendocrine cells. This form often grows quickly and requires treatment with chemotherapy.
- Sarcoma: This is a rare form of bladder cancer that originates in the muscle cells of the bladder.
The main forms of treatment for bladder cancer are surgery, chemotherapy, biological therapy, and radiation therapy. A combination may be used.
Treatment will depend on the location and stage of the cancer, the patient's overall health, age, preferences, and their support system.
Surgical options are available for all stages of the disease.
A transurethral resection (TUR) can treat stage 0 and 1 bladder cancer. A cutting tool is inserted into the bladder, and the surgeon removes small tumors and abnormal tissue and burns 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 removes the portion of the bladder that contains cancer cells.
A radical cystectomy will remove the entire bladder and possibly the surrounding lymph nodes, the prostate and seminal vesicles, and the uterus, ovaries, and part of the vagina.
Reconstructive surgery will be needed to provide a new way for the body to store and remove urine.
A piece of the intestine may be used to create one of the following:
- A urinary conduit, a tube to take the urine from the kidneys to a pouch (urostomy bag) on the outside of the body
- A cutaneous continent urinary diversion, a small reservoir for urine that can be drained through a hole in the abdomen using a catheter
- A neobladder, a reservoir that is attached to the urethra, allowing normal urination, possibly with the help of a catheter.
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.
Chemotherapy uses drugs to target and 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, and after each period of treatment there is a period of rest to allow the body time to recover.
However, chemotherapy and affect other cells in the body, leading to several side effects.
- nausea and vomiting constipation or diarrhea
- increased bleeding or bruising
- increased risk of infection
- loss of appetite
- hair loss
- mouth sores
The effects depend on the quantity of drugs used and how they are taken. If administered directly to the bladder, the side effects are usually milder. Side effects normally resolve once a course of treatment has finished.
Early-stage 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 (TB). In BCG therapy, a catheter is used 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 is normally given once a week for 6 weeks. It often begins shortly carrying out a TUR.
Interferon is another biological therapy option. The immune system makes this protein to fight infection, and a synthetic version can be used to fight bladder cancer, sometimes in combination with BCG.
In 2014, a study published in Nature showed how an antibody drug, atezolizumab (Tecentriq) can make it easier for the immune system to find and destroy cancer cells. In 2016, was approved as a therapy by the US Food and Drug Administration (FDA).
Radiation therapy is used but less frequently than other treatments. It is often used alongside chemotherapy. Radiation therapy can help kill cancer that has invaded the muscular wall of the bladder. It may be helpful for people who cannot 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 dosage and the area targeted by the beams.
- bladder symptoms, such as discomfort, frequency, or blood in the urine
- nausea and vomiting
- skin irritation in the targeted areas
If bladder cancer occurs once, there is a high risk that is will come back, so regular monitoring is usually recommended every 3 to 6 months.
Sometimes bladder cancer does not go away. Instead, it becomes a chronic disease. Regular treatment will be needed to keep the cancer in check.
In the early stages, most symptoms are related to urination.
Blood in the urine: The most common symptoms is hematuria, or blood in the urine. This may be highly visible, altering the color of the urine completely, or it may only be 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: These can also be affected. The person may need to urinate more frequently than usual. There may be a "stop and start" flow, or there may be pain or a burning sensation during urination, known as dysuria.
In the later stages, there may be back pain, weight loss, swelling in the feet, bone pain, and an inability to urinate.
Symptoms of bladder cancer can resemble those of a less severe problem such as a bladder infection. It is important to seek medical advice if symptoms persist, because effective treatment is more likely with an early diagnosis.
The cause of bladder cancer remains unknown, but genetic mutations may play a role. These may be inherited or they may develop during a person's lifetime.
The use of tobacco and exposure to chemicals may bring about changes that lead to blader cancer, but these appear to affect people in different ways.
Inherited genetic factors in themselves are not thought to be a major cause of bladder cancer, but they may make a person more likely to react to the effects of tobacco and certain industrial chemicals.
Some risk factors have been identified, of which smoking is the most important. Smokers are at least three times more likely to develop bladder cancer than non-smokers.
Other risk factors include:
- bladder defects that are present from birth
- undergoing chemotherapy and radiation therapy
- having chronic bladder infections and irritations
- exposure to certain chemicals, including aromatic amines and arsenic in drinking water
- low fluid consumption
- personal or family history of bladder cancer
- being male and white
Some medications and dietary supplements, such as pioglitazone (Actos) and aristolochic acid, may increase the risk.
These mainly come from plants in the Aristolochia family, such as birthwort, or Dutchman's pipe, commonly used in traditional medicine. A toxin in these plants has been linked to kidney problems and cancer in the long term.
People in the following types of employment may have an increased risk of bladder cancer, likely due to exposure to certain chemicals:
- manufacturing of rubber, leather, textiles, and paint products
- machine operating
- truck driving
Those who smoke and work in one of these industries have a higher risk, as the carcinogenic effects are often compounded.
However, bladder cancer can develop even without these risk factors.
If a diagnosis is confirmed, additional testing will determine the stage of the cancer. Tests include CT and MRI scans, chest X-rays, and bone scans.
Staging describes how far the cancer has spread and determines which treatment is suitable.
There are different ways of classifying the stages of cancer. One way of staging bladder cancer is in five stages:
- Stage 0: Cancer cells occur on the outer surface of the inner lining of the bladder. This can be referred to as "carcinoma in situ"
- Stage 1: Cancer occurs within the inner lining, but has not invaded the lamina propria or muscular wall
- Stage 2: Cancer has invaded the muscular wall but has not spread from the bladder
- Stage 3: Cancer has spread through the wall to the tissue surrounding the bladder, including potentially the prostate, uterus or vagina
- Stage 4: Cancer has spread to other sites in the body, such as the lymph nodes, bones or other organs such as the lungs or liver.
The stage at diagnosis will affect treatment options and outlook.
The doctor will ask the patient about their symptoms and medical history and carry out a physical examination. Tests can help confirm a diagnosis.
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.
This is inserted into the bladder through the urethra.
The cystoscope can also collect cell samples, or a biopsy, for testing.
Cystoscopies usually involve a local anesthetic and are carried out in a doctor's office. If general anesthetic is needed, the procedure will take place in the hospital.
The following imaging tests can help confirm a diagnosis and reveal whether the cancer has spread within the body:
- Pyelogram: A contrast dye is injected into the bladder, either into a vein or by using a direct catheter. The dye outlines the bladder and associated organs, making any tumors visible on X-rays.
- CT scan: This can help determine the shape, size, and position of any tumors that might be in the bladder, kidney, or ureters.
- Ultrasound and sonography: These can be used to determine the size of any tumors present and whether the cancer has spread beyond the bladder to nearby tissues or organs.
Urine can undergo various tests:
- Urine cytology: The sample is examined for cancer cells. A negative result does not always guarantee that there is no cancer.
- Urine culture: The sample is placed in a growth medium and monitored for signs of bacterial growth. The bacteria can then be identified, and the diagnosis may show 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.
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.
Biopsy samples can also be taken using a thin, hollow needle. These are called needle biopsies and are often guided by CT scan and ultrasound.
The United States Preventive Services Task Force (USPSTF) does not recommend routine screening for bladder cancer, as there is little evidence that screening improves long-term health outcomes. Individuals may also undergo stress and unnecessary intervention in the case of a false positive result.
However, avoiding risk factors may help reduce the chance of getting it. This includes not smoking, being careful with chemicals, drinking plenty of water, and eating a variety of fruit and vegetables.
The American Cancer Society notes that if bladder cancer is found in the earliest stage, stage 0, the chance of surviving at least 5 years is 98 percent.
If it reaches other parts of the body, the chance of successful treatment are lower, because it is harder to treat. If diagnosis occurs at stage 4, the chance of a person surviving 5 years or longer is 15 percent.
Early diagnosis significantly improves the chance of successful treatment, but treatment is possible even in the later stages of bladder cancer.