What Causes Bladder Cancer?

What Causes Bladder Cancer?

Bladder cancer a common type of cancer that usually begins in the cells lining your bladder, which is also referred to as the transitional epithelium. Just as the other types of cancer, bladder cancer develops into a life-threatening condition. However, 50% of its cases with an early diagnosis are treatable.

Bladder cancer begins when there is a mutation or change in the bladder cell’s DNA structure, developing an uncontrolled growth. This mutation means that the bladder cells grow and reproduce uncontrollably forming a lump of cells called a tumor. The possible cause of bladder cancer has not yet been identified, although, it is linked with exposure to some chemicals and radiation.

Risk Factors for Bladder Cancer

While the exact cause of bladder cancer has not yet been identified, some factors have been found to accelerate and catalyze its development. These factors include:

Exposure to Industrial Chemicals

Exposure to some industrial chemicals is one of the common risk factors catalyzing the development of bladder cancer. Research have shown that exposure to industrial chemicals has contributed to about 25% cases of bladder cancer. The chemicals that are known to increase the risk of bladder cancer development are as follows:

• Benzidine
• Aniline dyes
• o-Toluidine
• Xenylamine
• 2-Naphthylamine
• 4-Aminobiphenyl

Some occupations are also linked to an increased risk of bladder cancer development. These occupations are manufacturing jobs that involve the processing of the following materials:

• plastics
• dyes
• paints
• textiles
• rubbers
• leather tanning

People with occupations such as taxi and bus driving have also been seen to increase the risk of bladder cancer development. The reason is that these people are regularly exposed to chemical fumes from the diesel and petrol.

The association between these types of occupations and bladder cancer was first discovered in the 1950s. Since that time, some regulations have been put forward to reduce certain chemical exposures. Some of the chemicals produced by these manufacturing companies have been banned as well. However, these chemicals are still associated with the increased risk of bladder cancer since it can take up to 30 years before the effects of these chemicals are realized.

Smoking

According to statistics, smoking is the leading risk factor for bladder cancer around the globe. The presence of carcinogenic or cancer-causing chemicals in the tobacco is the main cause. If you have smoked tobacco for several years, the carcinogenic chemicals flow into your bloodstream and are filtered by the kidneys, so they can be excreted through urination. Therefore, this process increases the exposure of your bladder to these harmful chemicals, since it functions as the storage for your urine. Due to its storage function, exposure to carcinogens can cause mutation of the cells lining the bladder that can in turn lead to cancer.

According to statistics, over 30% of bladder cancer cases are as a result of smoking, which means that smokers are more likely to develop bladder cancer compared to non-smokers.

Other risk factors leading to bladder cancer development include:

• Diabetes - some treatments for type 2 diabetes have been linked in causing bladder cancer.

• Radiotherapy - is used to treat any cancer from neighboring organs such as the organs in the digestive system.

• Gender - according to statistics, men are more likely to be diagnosed with bladder cancer compared to women. However, women have the likelihood to die due to bladder cancer compared to men.

• Age - older people are more likely to be diagnosed with bladder cancer compared to the young due to a weakened immune system. Statistics show that about 70% of all bladder cases are from the older people above 65 years.

• Race - Black people are less likely to be diagnosed with bladder cancer compared to the White. However, the Blacks are more likely to die from this type of cancer compared to the Whites.

• Chemotherapy - a history of a previous chemotherapy treatment can also be a major risk for bladder cancer development.

• Previous surgery for prostate cancer - the removal of certain parts of the prostate gland can increase a man's risk of developing bladder cancer.

• Untreated schistosomiasis infection - a schistosomiasis infection is rare and is caused by a certain parasite living in fresh water.

Additional factors:

• presence of bladder stones for a long time
• occurrence of menopause at the early stages
• chronic infection of the urinary tract 
• having a catheter in your bladder for a long time

How Bladder Cancer Spreads

As discussed earlier, bladder cancer starts in the cells lining the bladder. At times, the cancer spreads into the neighboring mucles of the bladder. In case the cancer penetrates into the bladder muscles, it is likely to spread throughout your body via the lymphatic system. When the bladder cancer spreads and develops in other organs of your body, it is said to be a "metastatic" bladder cancer.

Types of Bladder Cancer

Transitional Cell Carcinoma (TCC)

This type of bladder cancer is the most common one, which usually originates from the urothelial cells in the bladder. This type of cancer contributes to about 90% of bladder cancers that come from the urothelial bladder cells. TCC can also arise from the ureters and the kidney's inner lining. This means that anyone diagnosed from this type of cancer have to be checked for the presence tumors in the whole the urinary tract. TCC can either be invasive or non-invasive depending on whether it remains in the bladder or not. The spread of this type of cancer can be catalyzed by either of the previously named risk factors.

TCC can be divided into two subtypes. They are:

1. Flat Carcinomas - the cancerous cells for this type of cancer arise and grow towards the hollow area of your bladder. They remain inside the bladder, hence, called as "non-invasive carcinomas."
2. Papillary Carcinomas - the cells of this type of bladder cancer grow in thin and small projections facing the inner lining of the hollow part of your bladder. The cells have low malignancy and are non-invasive as well.

Other types of cancer originating from the bladder and are less common compared to the transitional cell bladder cancer include:

• Adenocarcinoma - this type contributes to about 1% of all bladder cancer cases. It develops from the mucus-producing glands found in the bladder, which is similar to colon cancer. This type of bladder cancer is invasive.

• Squamous cell carcinoma - this type of bladder cancer accounts for 2% of bladder cases. It develops from the squamous cells of the bladder. Squamous cells are flat and thin cells resembling the cells in the surface of your skin. This type of bladder cancer is also invasive.

• Sarcoma - this is a very rare type of bladder cancer originating from the bladder muscle cells.

• Small cell carcinoma - this type of bladder cancer contributes to about 1% of cancer cases around the globe. It develops from the nerve cells commonly known as neuroendocrine cells. This type of cancer grows very fast and requires an immediate treatment through chemotherapy.

Bottom Line

Bladder cancer is a very serious and common type of cancer that attacks the transitional epithelial cells of your bladder. It is very unfortunate that the exact cause of bladder cancer has not yet been identified. However, some risk factors have been identified as associated with bladder cancer. These factors include your cancer history, any previous chemotherapy and radiotherapy medications, smoking, and exposure to some carcinogenic chemicals, among others. Although you can develop bladder cancer in the absence of these risk factors, it is still better to avoid all the risk factors that are associated with it.