Smoking is easily the biggest preventable cause of cancer. Research has positively established that smoking causes cancer.

In the 20th century, smoking has killed more people from cancer than all deaths from World War 1 and 2 combined.

There is no way you can reduce the risk. The risk remains equally high, whether you smoke a light cigarette or a cigarette with a filter. These do not reduce the smoking dangers in any way.

The risk of cancer is directly proportional to the severity of smoking, meaning that the more you smoke, the higher is the risk.

However, the number of years you have been smoking is more significant in increasing your risk. Research found that the number of years you have been smoking is the biggest factor influencing your risk.

If you have been smoking for the last 20 years, the risk is much higher than if you were smoking for 10 years.

Research has shown that a smoker’s risk of developing lung cancer begins to increase at the age of 40 years. By the age of 70, the smoker’s risk of developing cancer skyrockets.

But, your risk of cancer from smoking significantly reduces after you give up smoking completely and permanently.


Why do all smokers not get cancer? Why do some stay protected?

Every smoker faces a risk of dying early. Some do die early while some live a long life. A lot of research went into finding the reason behind this anomaly and the results pointed to the genetic constitution of the individual.

The constitution of every individual is different and so is the genetic makeup. It is this difference that makes a particular individual more prone to falling prey to health risks while some are sort of, protected by their genetic structure.

It is because of the genetic variation that you see people with similar smoking habits facing different consequences. Some fall seriously ill and die while others do not.

It is a fact that smoking is a leading risk factor that can cause cancer, more particularly lung cancer.

Smokers who live a long life are protected by their genes, which promote longevity. Longevity genes help the body cells maintain and repair themselves and protect them from the damage of smoking. People with these genes are linked with an 11% lower incidence of cancer.

These genes protect their hosts from environmental damage, like that caused by the chemicals from cigarettes.

Smoking and lung cancer statistics

Cigarette smoking is the leading risk factor causing cancer among smokers. Other tobacco products such as pipes and cigars are also potentially dangerous.

Out of the 7000 chemicals in cigarette smoke, at least 70 are reported to be carcinogenic.

It is not only the heavy smokers but also the light or the occasional smokers who are at a higher risk than a nonsmoker.

According to a study, people who smoked about 20 cigarettes a day had a 26 times higher risk of lung cancer than non-smokers. And people who smoked around 3 cigarettes a day had 6 times the risk of lung cancer than non-smokers.

However, the lung cancer risk increases with the period and intensity of tobacco consumption.

Even if you have quit smoking, your risk reduces but you still are at a higher risk than a nonsmoker.

In the United States, 90 percent of lung cancers are caused by smoking.

In the United Kingdom, smoking is associated with an estimated 86% of lung cancer cases. More than 4 in 5 lung cancers are caused by smoking. Lung cancer is the most common cause of death among all cancers in the United Kingdom.

Worldwide, cigarette smoking alone is responsible for more than 80 percent of all lung cancer cases.

15 to 20 percent of patients who have lung cancer have never smoked in their lives. They could be secondhand smokers though.

In the United States, exposure to secondhand smoke causes about 7,330 lung cancer deaths among nonsmokers every year.

Facts: Smoking and cancer 

  • Every study conducted across the globe has strongly linked tobacco with cancer. It is classified as a group A (or 1) carcinogen – meaning a definite and highly risky carcinogen.
  • Smoking is the single biggest cause of cancer in the world.
  • Chewing tobacco causes cancer and has been associated with oral cancer and cancer of the pancreas.
  • Lung cancer from smoking is a known fact, but smoking has also been linked to cancer of the mouth, throat, esophagus, bladder, kidneys, and cervix.
  • Secondhand smoke is also a high-risk cancer cause.
  • About 30 percent of all cancer deaths and 87 percent of lung cancer deaths are due to smoking.
  • About 10% of smokers die of cancer.
  • The risk of developing lung cancer is as much as 23 times higher in male smokers compared to people who do not smoke.
  • Smoking increases your risk of contracting 15 types of cancer.
  • One-third of cancer deaths in developed countries are due to tobacco use.
  • According to the American Cancer Society, more than 85% of lung cancer deaths are caused by smoking.
  • In the U.K., smoking accounts for 25% of cancer deaths.
  • Smoking a cigar or light cigarette does not reduce your cancer risk.
  • Most people believe that smoking a cigar is safer than smoking a cigarette.  But, one cigar contains as much tobacco as a pack of cigarettes.

Cancers caused by smoking in other parts of the body

Nearly 9 out of 10 lung cancers are caused by smoking cigarettes. Besides lung cancer, smoking increases the risk of cancer in other parts of the body as well.

Smoking causes cancer almost anywhere in your body. Even smokeless tobacco, such as chewing tobacco, also causes cancer mostly of the esophagus, mouth, and pancreas.

Smoking causes cancer of the mouth, pharynx, nose and nasal sinuses, larynx, esophagus, bowel, liver, pancreas, stomach, kidneys, ovaries, bladder, cervix, and certain types of leukemia. There is a small risk of breast cancer as well.

How smoking causes cancer?

Cigarette smoke or tobacco smoke is 10,000 times more concentrated with pollutants than automobile pollution during rush hour on the freeway. It is the tar in cigarette smoke that contains more than 60 known carcinogens, which interfere with the normal growth of the cell. These carcinogens can damage the DNA in a normal cell. This causes the normal cell to mutate and become a cancer cell.

There are more than 4,000 chemicals in cigarette smoke of which 70 are known to be carcinogenic with mutagenic properties.

These chemicals alter the structure of the DNA in the body cells. It is the DNA of the cell that controls its growth and function. When the DNA is altered, the cells mutate, grow without control, and get converted to cancer cells.

They even weaken the immune system, making it difficult to repair any damaged body cells.

Many chemicals in cigarette smoke such as benzene, polonium-210, benzo (a) pyrene, and nitrosamines cause DNA damage.

As if this isn’t bad enough, other chemicals like chromium make toxins like benzo(a)pyrene stick to DNA, further increasing the chances of serious damage.

Again, arsenic and nickel prevent the repair of the damaged DNA increasing the chances of the healthy cells turning into cancer cells.

How can smoking-related cancers be prevented?

The most important thing or the only thing you can do to nullify your cancer risk from smoking is to quit smoking cigarettes for good.  You can do it on your own or with help of effective aids. You should also see that you are not exposed to secondhand smoke. Statistics have shown that this type of smoking is dangerous

When you quit smoking, a lot of damage done to your body by smoking starts reversing over time.

It lowers the risk for 12 types of cancer: cancers of the lung, larynx, oral cavity and pharynx, esophagus, pancreas, bladder, stomach, colon and rectum, liver, cervix, kidney, and acute myeloid leukemia (AML).

If you have been a heavy smoker for many years and now past 50 years, you should get yourself screened for cancer. You should also get yourself annually screened if you have been a smoker and also if you have quit in the past 15 years.

Screening for cancer involves certain blood tests and imaging studies. You should also undergo genetic testing to assess your cancer risk once.