Bladder cancer is the uncontrolled and abnormal multiplication of cells in the urinary bladder. Like other cancers, bladder cancer begins when there is a change in the structure of DNA. As DNA carries information regarding the growth of our cells, this structural change, also referred to as a mutation, enables cells to grow and reproduce uncontrollably. As a result of this, cancerous tumors are created. When this process takes place in our bladder, it brings about lump of tissue and causes bladder cancer.
So, what leads to the structural change of DNA? Actually, at the moment scientists are still not fully aware of what causes genetic mutations and what encourages bladder cancer to develop. However, several factors that may increase the chances of acquiring this cancer have been identified. Among them, cigarette smoking stands out as the most common cause of bladder cancer. Besides, age, job, family history and exposure to chemicals are also strongly associated with a large percentage of cancer cases detected. Other risk factors such as chemotherapy, radiation therapy, or long-term inflammation are as well needed to be taken into consideration.
Cause of Bladder Cancer:
Top six causes of all cancers: including causes of bladder cancer
Regarded as the most common type of bladder cancer, urothelial carcinoma, also known as “transitional cell carcinoma”, is highly attributed to smoking. As we all know, there are more than 40 different cancer-causing chemicals (carcinogens) contained in tobacco. These toxic chemicals are inhaled into the lungs before being absorbed and delivered by the bloodstream to our kidneys. After the kidneys filter these substances into our urine, the urine travels through tube-like structures called ureters into our bladder. Here, the carcinogens come into direct contact and react with the transitional cells that form mucosa, the innermost layer of the urinary bladder. This leads to the genetic mutations mentioned above, and eventually become the causes of bladder cancer.
Researches show that over half of all bladder cancer cases are strongly associated with smoking. In fact, the more a person smokes, the more likely he or she may acquire cancer. The chance of developing bladder cancer in people who smoke is six times higher than non-smokers. Therefore, giving up smoking can decrease the risk of getting bladder cancer, although it still takes years for an ex-smoker to reach the level of those who have never smoked. Anyway, stop smoking completely and immediately is the first thing a patient should do when he or she is diagnosed with bladder cancer.
Occupation and exposure to chemicals
Since the 70s and 80s of the 20th century, a link between causes of bladder cancer and some certain jobs has been identified. Statistics show that people working in manufacturing jobs that involve rubber, textiles, chemicals, dyes, plastics are at a higher risk of getting bladder cancer. Hairdressers, truck drivers, pesticide applicators are also considered to be more prone to cancer. This is because they have to constantly work with toxic chemicals, which increase their chance of developing cancerous tumors.
In fact, exposure to chemicals is responsible for up to 25% of all bladder cancer cases, making it the second biggest risk factor of this disease, just only after smoking. The chemicals known to boost the risk of having bladder cancer after a long time of exposure include benzidine, xenylamine, 2-Naphthylamine, aniline dyes, arsenic, 4-Aminobiphenyl and so on.
Since the discovery of the relation between causes of bladder cancer and the aforementioned occupations, stricter regulations regarding working with cancer-causing chemicals have been adopted, and many of these poisons have been put under prohibition. Despite those actions, the current rate of cases related to occupations is still quite high, as bladder cancer can take up to 25 years after initial exposure to begin its development. However, thanks to the introduction of more rigorous regulations as mentioned above, it is hopeful that in the future this proportion will decrease.
Age and family history
As men are more prone to smoking and exposing to chemicals, they are at higher risk of getting bladder cancer than women. And when it comes to male sex, age and family history are also regarded as risk factors. In fact, up to 90% of those diagnosed with bladder cancer are at their mid-fifties, though some exceptional cases may be found in the third or fourth decades of life. Besides, a family member with a history of bladder cancer may intensify the predisposition to contracting this disease.
Other risk factors
The risk of developing bladder cancer is higher for people who have radiotherapy to treat previous cancers taking place in areas adjacent to the bladder, or those who get chemotherapy with cyclophosphamide (cytoxan). Moreover, hematuria (also known as bleeding in the urine), which is the most common symptoms of bladder cancer, can be wrongly attributed to these therapies. In other words, bladder cancer prognosis may take longer for those who are previously treated with radiotherapy or chemotherapy.
For people, especially those suffering from paralysis, who have foreign bodies inserted into their bladder (for instance, a permanent tube to drain away urine), the predisposition to bladder cancer is also higher, as disease can be caused by chronic inflammation or irritation.