Smoking - Its Impact on Bladder Cancer Risk

Introduction

Smoking causes many problems, like heart disease, lung cancer, and stroke. It may also cause death. Research has found that smoking may cause bladder cancer in both men and women. The chemicals in tobacco smoke may end up in the urine and are responsible for harmful effects on the bladder.

What Is Bladder Cancer?

The bladder is a hollow sac that stores urine before it is emptied by the body through urination. In the case of bladder cancer, an abnormal growth of cells occurs in the bladder. This causes tumors in the bladder. Over time, this tumor may invade the bladder lining and later invade the deeper part of the muscular layer of the bladder wall.

Bladder cancer is mainly caused by smoking. Other risk factors of bladder cancer include

• Smoking.

• Exposure to chemicals at work.

• Infections.

• Use of urinary catheters for long periods.

• Radiotherapy for cancer was taken previously.

• Medical conditions like diabetes, family history, and being overweight.

Symptoms of bladder cancer include

• Presence of blood in the urine.

• Need to urinate often and more urgently.

• Pain or burning sensation occurs during urinating.

Bladder cancer at an early stage can be treated by surgery or chemotherapy. Advanced conditions of bladder cancer may require the removal of the bladder. An external drainage bag is needed to store the urine in such cases.

What Is the Link Between Smoking and Bladder Cancer?

Recent studies have found that smoking can be a risk factor for bladder cancer. Cigarette smoking is considered a leading cause of preventable disease and death in the United States. Smoking can cause cancer in more than 15 parts of the human body.

It is estimated that more than half of bladder cancers in men and women in the US are caused by smoking. Hence, smoking is considered a leading preventable risk factor, whether it is due to workplace exposure or industrial chemicals.

Some chemicals present in tobacco smoke are carcinogenic, and these may be responsible for causing mutations in the cells of the body. These chemicals reach the urine after smoking and remain there for up to 18 hours. This type of exposure can bring about genetic changes in the cells of the bladder and may lead to the development of bladder cancer.

The risk of getting affected with bladder cancer increases with smoking. The risk of bladder cancer depends on the duration (the number of years of smoking) and intensity (the number of cigarettes smoked daily). The duration of smoking has a greater effect. Smokers are three times more likely to get affected with bladder cancer when compared with nonsmokers.

A meta-analysis (analysis of multiple studies) found that the risk of bladder cancer is 3.5 times higher among current smokers compared to nonsmokers and that improvement is 2 times higher for former smokers.

Another meta-analysis found a similar increase in the risk of bladder cancer among male and female smokers and a higher risk among Europeans than Asians. Some genetic variants are associated with an increased risk of bladder cancer among smokers.

Second-hand smoke (SHS) or involuntary smoking may affect children, pets, and nonsmokers. These also inhale the same carcinogens as smokers. SHS may cause a 20 to 30 percent increase in lung cancer risk among nonsmokers.

A meta-analysis has found that SHS exposure was linked to a 22 percent increase in bladder cancer risk. SHS can be determined by knowing about the blood levels of cotinine, a chemical present in the body after exposure to nicotine.

What Are the Impacts of Smoking on Bladder Cancer Risk?

Cigarette smoke contains 7000 chemicals; out of these, 70 chemicals are known to cause cancer and are called carcinogens. The carcinogens in cigarette smoke that are considered most damaging include polycyclic aromatic hydrocarbons, nitrosamines, aromatic amines, 1,3, butadiene, benzene, aldehydes, and ethylene oxide. The chemicals 2-naphthyl amine and 4-aminobiphenyl are responsible for causing bladder cancer among smokers.

The human body normally removes a variety of toxins through urine. When harmful chemicals are inhaled through cigarette smoking, they are absorbed from the lungs into the blood before being filtered from the kidneys and collected in the bladder. When carcinogen-containing urine is stored in the bladder for hours, the lining is exposed to harmful chemicals. Some of the chemicals get to or damage DNA (deoxyribose nucleic acids), leading to mutations and the formation of tumors. Other chemicals indirectly increase cancer risk by affecting the immune system and promoting inflammation.

Apart from causing bladder cancer, these cause the following effects:

• Irritation of the bladder.

• Worsen the symptoms of an overactive bladder and interstitial cystitis ( chronic, painful bladder condition in women).

• Frequent urination.

• Coughing spasms may induce urine leakage.

• Kidney cancer.

• Kidney stones.

• Erectile dysfunction.

• Infertility.

Vaping is also similar to smoking. The action of inhaling and exhaling vapor containing nicotine and other chemicals through a device is known as vaping. The exposure to harmful chemicals is less when compared to smoking. Chemicals and carcinogens exposed in the case of e-cigarettes are less than in smoking.

A study has found that even vaping is responsible for bladder cancer and has shown 63 chemicals (toxins and carcinogens) in the urine of vapers.

Though vaping is a little better than smoking, it is better not to switch to both options. Both, together, may be very harmful and lead to bladder cancer.

Quitting smoking does help reduce the risk of many cancers. Particularly for bladder cancer, the risk drops steadily as the number of years since quitting smoking increases. A definite reduction in the risk of bladder cancer may be observed within 10 years.

Besides reducing the risk of bladder cancer, quitting smoking has many health benefits.

• Decreased heart rate and blood pressure.

• Reduced carbon monoxide in the blood.

• Improved ability of oxygen-carrying capacity of the blood.

• Improvement in circulation.

• Improvement in lung function.

• Increased life expectancy.

Conclusion

Smoking causes serious health issues, including different types of cancer in the human body. The risk of getting bladder cancer is also high for smokers when compared to nonsmokers. Hence, it becomes important to know about the impacts of smoking on bladder cancer risk. Knowledge about the condition may help in the prevention of the disease.