Smoking and Cancer - A Guide to Stop Smoking

Cancer affects 1 in 3 people in the UK and is one of the biggest causes of death along with heart disease and strokes. Cancer can occur as a result of a variety of factors but the single biggest factor is that of smoking.

Other causes include age, genetics, the body’s immune system, viruses and bacteria and lifestyle.

In fact, smoking is the main cause of cancer throughout the world. (Source: Cancer Research UK, July 2008)

We often think of cancer in the singular, but there is more than one type of cancer which includes: lung, bowel, breast, cervix, bladder, throat, stomach etc. There are 200 types of cancer in all.

How does cancer occur?

Your body contains millions of cells which constantly grow and reproduce. These cells carry out a wide range of functions in the body which ensure that it is fit and healthy.

But, these cells can start to grow in an uncontrollable way and spread to form a tumour. A tumour can either be benign or malignant, but it’s the malignant one that causes the most damage. A malignant tumour is composed of cancerous cells which then spreads and damages other areas of the body.

This is what is known as cancer.

Smoking causes a number of cancers but the most popular one is lung cancer. Nine out of ten cases of lung cancer are caused by smoking and this has the lowest survival rate of all forms of cancer.

But, the vast majority of these can be prevented if the person stops smoking.

The number of smokers in this country has reduced dramatically which is also reflected in the cancer statistics. Figures from Cancer Research UK show that the number of people who die from lung cancer has halved in the last 50 years which is very good news.

There is still a long way to go and there are still people taking up smoking but the message is getting through about the health risks of smoking.

Other types of cancer caused by smoking

We know that lung cancer is caused by smoking but cancer is responsible for at least a dozen other cancers which include:

• Mouth
• Throat
• Nose and sinuses
• Breast
• Oesophagus
• Ovarian
• Cervical
• Liver
• Pancreas
• Stomach
• Bowel
• Kidney
• Bladder

It also causes certain types of leukaemia and Hodgkin’s lymphoma.

Does every smoker get cancer?

No, but it does increase the risk. A smoker is more likely to get cancer than a non-smoker, and around half of all smokers die of cancer or a smoking related disease.

There are some people who smoke and don’t develop cancer just as there are some people who have never smoked but still develop the disease.

This doesn’t seem fair but there are always exceptions to the rule. Evidence still shows that on average, smokers are at greater risk of developing cancer than non-smokers.

If you are in contact with smokers or have a partner that smokes then be aware that you are at risk, even if you are a non-smoker. There is a link between passive smoking and health problems which also includes cancer. There is some evidence to show that non-smokers have a 20% risk of developing lung cancer from breathing in second hand smoke.

Your risk of developing cancer is determined by your genes, environment and lifestyle. Stopping smoking, eating healthily, taking exercise and avoiding pollutants doesn’t guarantee a cancer-free existence but it will reduce the risks.

How smoking causes cancer

Many of the chemicals present in cigarette smoke are not only toxic but are carcinogenic as well. There are about 4,000 chemicals in this smoke and a sizeable percentage of these cause cancer.

Examples of these include arsenic, chromium and cadmium.

What happens is that these chemicals enter your body via your lungs and then spread themselves around. As they do so they damage your DNA and cause unexpected changes in your genes. This leads to abnormal cell division and cancer.

These chemicals cause havoc in other parts of the body: nitrogen oxide constricts the airways, toluene affects the development of brain cells and acrolein irritates the lungs.

And, combinations of these chemicals are more dangerous than individual ones.

There are some types of cancer which are caused by the combination of smoking and alcohol. Alcohol and smoking is a popular combination especially if you enjoy a smoke whilst in the pub or a night in with friends.

But these can be a lethal combination.

When these two are combined their effects are much worse. For example, smoking and alcohol can cause liver, mouth and oesophageal cancers. And alcohol can worsen the effects of other cancers in smokers such as stomach cancer.

This problem can be worsened by the addition of a poor diet. There are some people who smoke, drink and have an unhealthy diet and these are all triggers for cancer.

Smokeless versions and cancer

There are alternatives to cigarettes such as chewing tobacco and ‘snuff’ but these are not without their risks. It is easy to assume that these won’t cause cancer because they are not inhaled into the lungs but the opposite is true.

These are equally as addictive as cigarettes and in some cases, the amount of nicotine absorbed is greater than that from cigarettes. Nicotine is absorbed more slowly which means that it remains in the bloodstream for longer.

There are a wide range of smokeless tobacco products but the one thing they all have in common is an increased risk of mouth cancer. Some types are riskier than others which are due to the amount of cancer causing chemicals that they contain.

These products are also linked to other forms of cancer such as oesophageal cancer, pancreatic and liver cancers. Plus there is evidence to show that they increase the risk of both gum and heart disease.
(Source: Cancer Research UK, Aug 2005)

They can contain as much as 28 different types of carcinogens but the worst of these are a group of chemicals called tobacco specific nitrosamines (TSNAs).

Some types of smokeless tobacco contain 100 times more TSNAs than cigarettes which make them an even greater risk than cigarettes.

There is evidence to show that some companies have taken this message on board and have brought out smokeless products with lower levels of TSNAs. However this doesn’t apply to all brands.

The message here is that smokeless tobacco is as addictive and dangerous as cigarettes. Do not consider switching from cigarettes to this in the belief that it is less harmful or will help you to quit smoking.

In many ways it is more harmful than cigarette smoking and should be avoided.

The best form of attack here is defence which means quit smoking. If you want to know about this then have a look at our Stopping Smoking section.

Smoking and your health - Guide to Stop Smoking Index:

• Smoking and your health
• Smoking and heart disease
• Smoking and cancer
• Smoking and strokes
• Smoking and halitosis

• Smoking and respiratory conditions
• Smoking and osteoporosis
• Smoking and throat disorders
• Smoking and eye problems
• Smoking and dental problems