This type of cancer occurs when the cells that make up the urinary bladder – starting with those that cover the organ – begin to grow uncontrollably. As more cancer cells develop, they can form a tumor and, if left untreated at first, spread to other parts of the body.
It is one of the most common tumors of the urinary tract and the ninth most common type worldwide. When compared by sex, occupies the sixth position among men, and the 19th among women. The estimated risk of a person having bladder cancer is 7.23 new cases per 100,000 men and 2.8 new cases per 100,000 women.
Types of bladder cancer
Bladder cancer is classified according to the cell that has been altered. There are three types:
- Transitional cell carcinoma: represents the majority of cases and starts in the cells of the inner tissue of the bladder;
- Squamous cell carcinoma: affects the thin, flat cells that can appear in the bladder after prolonged infection or irritation; and
- Adenocarcinoma: starts in glandular (secretory) cells that can form in the bladder after a long time of irritation or inflammation.
Bladder cancer is considered superficial when it is limited to the tissue lining the bladder, and invasive when it spreads through the lining of the bladder and invades the muscular wall. It can affect nearby organs or lymph nodes.
Bladder cancer symptoms and signs
Blood in the urine is considered the main warning sign of bladder cancer. The amount of blood is not always enough to change the color of the urine, but laboratory tests detect small amounts of blood present. Early cases of the disease usually cause little bleeding and little, if any, pain.
It is important to note that other diseases such as infections and kidney stones can also result in blood in the urine, hence the need for a more detailed examination to verify the exact cause;
In addition to blood in the urine, symptoms of bladder cancer can also be the following:
- Changes in urinary habits – such as urinating more often than usual;
- Painful or burning sensation when urinating;
- Urge to urinate; and
- Problems urinating or weak urine flow.
Bladder cancer diagnosis
The diagnosis of bladder cancer can be made by urinalysis and imaging tests, such as computed tomography and cystoscopy (internal investigation of the bladder using an instrument equipped with a camera). During cystoscopy, material may be removed for biopsy.
The probability of cure will depend on the stage (extent) of the cancer (superficial or invasive) and the age and general health of the patient.
Surgery, alone or in combination with other treatments, is the most commonly used approach.
In early stages, tumors can be removed. The problem is that, over time, new cancers can form in other parts of the bladder.
There is also the option of total bladder removal or combined use of surgery with other approaches. Treatment options will depend on the degree of progression of the disease.
In summary, the options for surgery are the following:
- Transurethral resection: surgery in which the doctor removes the tumor via the urethra;
- Partial cystectomy: surgical process that removes only part of the bladder; and
- Radical cystectomy: complete removal of the bladder, with the construction of a new organ to store the urine.
Radiation therapy can be used alone or in combination with chemotherapy, and is sometimes used after surgery or as a replacement for surgery.
As for chemotherapy, which can be neoadjuvant (performed before surgery) or adjuvant (performed after the surgical process), there are two alternatives:
- In the systemic form, ingested as a drug or injected into a vein; and
- In the intravesical form, applied directly to the bladder through a tube introduced through the urethra.
For muscle invasive tumors, treatment options are the following:
- Radical cystectomy – is the standard treatment for cases of localized muscle-invasive tumor. The clinical condition of the patient and the presence of comorbidities are evaluated for the indication of this treatment. Overall survival at five years is around 65%, and at 10 years, around 45%; and
- Lymphadenectomy – is the removal of part of the lymph nodes and should always be performed, since it is associated with better oncological results.
Laparoscopic surgery (robotic/pure laparoscopic), when compared to open surgery, has a lower complication rate, less need for transfusion, better pain control, and shorter hospital stay. As for oncological results, the two exhibit comparable results.
Staying away from risk factors is one way to prevent bladder cancer. Smoking, among the most important risk factors for the development of bladder cancer, is present in 50 to 70% of cases, and smokers are three times more likely to have the disease than non-smokers.
Second comes occupational exposure in environments with chemical compounds such as aromatic amines (such as benzidine and beta-naphthylamine, used in the dye industry), responsible for about 10% of cases. The professionals most at risk of getting bladder cancer are painters, mechanics, typographers, hairdressers and truck drivers (due to diesel fumes).
Use of the diabetes drug pioglitazone is associated with an increased risk of bladder cancer. Some dietary supplements that contain aristolochic acid also increase the risk of developing the tumor.
However, some risk factors cannot be controlled, such as:
- Race and ethnicity – whites are twice as likely to develop bladder cancer (the reasons for this are still unknown);
- Age – about 90% of bladder cancer patients are over 55 years of age;
- Chronic irritation and infections: kidney or bladder stones and recurrent urinary infections have been linked to bladder cancer; and
- Family history: people who have or have had family members with bladder cancer are at increased risk of the disease.
It is important to clarify that having one or some of the risk factors, controllable or not, does not necessarily mean that the person will have bladder cancer.