What is Bladder Cancer?
The bladder is a muscular, hollow organ in the pelvis that stores and releases urine. Bladder cancer is a disease where the cells that make up the bladder multiply uncontrollably and form a tumour that may invade and spread to the other parts of the body. According to the Globocan 2020 statistics, the incidence of bladder cancer in Singapore ranked 16 among the different cancer sites.
A person with bladder cancer may experience blood in their urine, painful urination or other symptoms that can greatly affect one’s quality of life.
Bladder cancer can be further categorised depending on histology type.
- Urothelial carcinoma — Also known as transitional cell carcinoma, it is the most common type of bladder cancer. It begins in the urothelial cells that line the inside of the bladder.
- Squamous cell carcinoma — Squamous cells are flat cells that are found on the surface of the skin but they can also be found in other parts of the body such as bladder and urachus. It is associated with chronic irritation of the bladder such as long-term use of a urinary catheter or other conditions such as cystitis.
- Adenocarcinoma — It derives from the bladder urothelium but displays a histologically pure glandular phenotype. This is uncommon.
- Small cell carcinoma — It begins in neuroendocrine cells and forms poorly differentiated epithelial bladder tumours. Small cell carcinoma is extremely rare.
What are the symptoms of Bladder Cancer?
Bladder cancer can be detected early due to various noticeable signs and symptoms. About 80% of bladder cancer patients experienced painless haematuria (blood in urine). Some symptoms are:
- Gross or microscopic haematuria (not visible to the eye)
- Irritative urinary symptoms such as frequent urination, urinary incontinence, and painful urination
- Obstructive urinary symptoms such as the feeling of incomplete voiding and intermittent urinary stream
- Advanced disease symptoms such as flank pain, pelvic pain, and anorexia, loss of weight and fever
Some of these symptoms may overlap with other urinary conditions such as urinary tract infections and should be investigated further.
When should I visit a doctor?
You should visit a doctor if you notice any discolouration in your urine, as this may be a sign of haematuria. Other indications are bothersome symptoms related to urination frequency and urgency.
As symptoms of bladder cancer are similar and can be written off as a urinary tract infection, diagnosis is often delayed until later stages. As such, it is important to consult your urologist for a proper diagnosis and further investigation.
What causes Bladder Cancer?
The exact causes of bladder cancer remain unclear. However, in general, cancer cells form when DNA accumulates mutations that cause them to divide uncontrollably. The genes that control cell division are oncogenes and tumour suppressor genes.
- Proto-oncogenes: In normal healthy cells, proto-oncogenes help cells to grow and divide. However, when proto-oncogenes mutate, it causes cells to evade apoptosis and grow out of control.
- Tumour suppressor genes: The role of the tumour suppressor gene is to regulate cell division and replication. A mutation in the tumour suppressor gene will result in the loss of its function, leading to abnormal cell growth and tumour formation.
Gene mutations can be acquired or inherited. Acquired gene mutations can be due to exposure to carcinogenic chemicals or radiation. Harmful chemicals can be absorbed in the blood and filtered by the kidneys and end up in the urine.
As such, the chemicals in the urine can introduce mutations to the bladder cells leading to cancer. Some individuals may also inherit genes that have a reduced ability to break down and get rid of certain types of carcinogenic chemicals.
What are the risk factors for Bladder Cancer?
The established risk factors for bladder cancer are listed below.
Modifiable risk factors
- Smoking — Harmful carcinogenic chemicals found in cigarettes may accumulate in the urine and damage the lining of the bladder. Cigarette smoking increases the risk of bladder cancer by 2 to 4 times.
- Chemical exposure — Certain industrial chemicals such as aromatic amines, benzidine, and beta-naphthylamine used in the production of dyes and rubber tires have been shown to be associated with bladder cancer.
Non-modifiable risk factors
- Age — The risk of bladder cancer increases with age. The median age at bladder cancer diagnosis is 65 to 70 years.
- Sex — Men are more likely to develop bladder cancer than women.
- Family history — Individuals who have a family history of bladder cancer are more likely to develop it themselves.
- Chronic bladder inflammation — Chronic urinary infections or inflammations and other causes of bladder irritation are associated with bladder cancer, especially squamous cell carcinoma of the bladder.
- Chemotherapy and radiation therapy — Chemotherapy drug cyclophosphamide can irritate the bladder and increase the risk of bladder cancer over a long period of time. Radiation therapy in the pelvic area can also increase the likelihood of developing bladder cancer.
How is Bladder Cancer diagnosed?
Bladder cancer is often detected due to the signs and symptoms. Various scans and tests can be performed to confirm the diagnosis and rule out other medical conditions.
- Physical exam — A digital rectal exam and pelvic exam can be conducted to detect a bladder tumour and assess its size.
- Urinalysis — It is performed to check for haematuria. Haematuria is usually a sign of benign conditions, but it could also be the first sign of bladder cancer.
- Urine cytology — Urine cytology involves the use of a microscope to detect any cancer cells or pre-cancer cells in urine.
- Urine culture — A urine culture test helps check for the presence of bacteria in the urine. It helps to rule out infection as the cause of symptoms.
- Cystoscopy — This involves the insertion of a narrow tube with a small camera through the urethra to examine the bladder.
- Biopsy — A small sample of the bladder tissue is taken to test for cancer cells. It is performed to confirm the diagnosis of bladder cancer. It also helps to determine the invasiveness and severity of the cancer.
- Imaging tests — Imaging tests such as computerised tomography (CT), retrograde pyelogram, intravenous pyelogram, magnetic resonance imaging (MRI), ultrasound, are used to examine the structures of the urinary tract. These tests can also help to check if the cancer has spread to other tissues and organs near the bladder or to the nearby lymph nodes.
What can I expect during my first consultation?
During the first consultation, a detailed medical history to better understand the symptoms will be taken, for example, possible risk factors, and family history of bladder cancer. If bladder cancer is suspected, other diagnostic and imaging tests for further evaluation will be required and these will rule out other medical conditions as well.
Can Bladder Cancer be cured?
The prognosis of bladder cancer depends largely on the individual’s age, general health, stage of cancer, and grade of cancer. The probability of a cure is high for early-stage bladder cancers which are often superficial with low malignant potential.
However, bladder cancer has the tendency to recur and will need continual assessment years after treatment. The 5-year survival rate for bladder cancer varies from 96% for carcinoma in situ (CIS) to 5% for those with distant metastasis (stage 4).
How is Bladder Cancer treated?
Treatment depends on a number of factors including the type, grade, and stage of cancer. Other considerations such as life expectancy, comorbidities, and side effects should also be included in the decision making when choosing the types of treatment.
Procedures
- Transurethral resection of bladder tumour (TURBT) — It is a common surgical treatment to remove superficial cancers that are confined and limited to the inner layers of the bladder. This also allows biopsy to be taken.
- Cystectomy — It is a procedure that removes all (radical) or part of the bladder (partial, for very selected cases) that contains the cancerous tumour. Chemotherapy may be performed before the surgery. After a radical cystectomy, a urinary diversion procedure such as neobladder reconstruction, ileal conduit, or continent urinary reservoir is performed to create a new way for urine to leave the body.
Chemotherapy
- Systemic chemotherapy — Cancer-killing drugs are delivered intravenously (via the veins) or intramuscularly (via the muscles) into the bloodstream and transported throughout the body. It is used before surgery to shrink a tumour or after surgery to kill any remaining cancer cells.
- Intravesical therapy — During intravesical chemotherapy, the drugs are delivered directly into the bladder using a catheter through the urethra. Intravesical therapy allows the drug to work on the urothelial cells without major side effects to other parts of the body.
Radiation therapy
- Radiation therapy uses high energy radiation to kill cancer cells. It is usually given along with chemotherapy to increase the effectiveness of radiation. External beam radiation therapy is often used to treat bladder cancer by focusing the radiation beam on the tumour.
Immunotherapy
- Immunotherapy works by eliciting or amplifying an immune response to fight against cancer cells. Bacillus Calmette-Guerin (BCG) is the most common intravesical immunotherapy for early-stage bladder cancer. It is delivered directly into the bladder through a catheter and triggers the immune system by interacting with the cancer cells.
Summary
Bladder cancer is one of the most common genitourinary cancers that affect both men and women. It is highly treatable when detected early, with a 5-year survival rate of about 96% for in-situ cases. The most common symptom of bladder cancer is the presence of blood in urine.
Most bladder cancers are highly treatable when detected early! If you suspect that you have bladder cancer, or experience the symptoms mentioned above, consult us for a proper diagnosis and treatment plan best suited to your needs.
