General information and statistics related to smoking and cancer.
Many people believe that smoking only causes lung cancer, which is definitely not the case. Smoking has also been linked to several other types of cancer such as cancer of the mouth, throat, stomach, bladder and colon and is also responsible for a large number of deaths from these types of cancer.
It is a fact that smoking cigarettes, pipes or cigars may lead to cancer of the mouth, oesophagus or larynx.
It is important to note that the consumption of alcohol together with cigarette smoking increases the risk of these types of cancer even more.
Statistics show that 54% of mouth cancers, 50% of cancers of the oesophagus and 70% of cancers of the larynx are attributed to smoking. Around 40% of stomach cancers are caused from smoking, as are 30% of cancers of the penis.
For females, there is a greater risk of developing cervical cancer if she is a smoker. 19% of cervical cancer cases can be attributed to smoking, although heavy smokers may have an increased risk of developing this type of cancer of up to 80%.
It is true however, that lung cancer is the most common form of cancer developed by smokers. Around 90% of all lung cancers are caused directly by smoking and statistics show that one in four smokers will eventually die of lung cancer.
In 2003 in the US, 157,200 people died from lung cancer only and around 170,000 new cases were diagnosed. Figures from the American Cancer Society show that more people died from lung cancer the following year. The American Cancer Society estimates
that there will be 224,210 new cases of lung cancer in 2014, with 159,260 related deaths.
Without a doubt, smokers are much more likely to develop lung cancer than non-smokers. Statistics for male smokers show that males have a 20% increased risk of developing lung cancer whilst female smokers have a 13% increased risk.
Smoking is the biggest avoidable risk of developing any form of cancer and once a person stops smoking the risks are reduced almost immediately.
Lung cancer history
Lung cancer was the first major disease to be associated with and directly linked to smoking in the 1950's. It was not a very common illness before the 1930's and the increase in lung cancer cases coincided with an increase in tobacco use.
Smoking cigarettes became hugely popular and widespread around the time of the First World War, when soldiers were freely supplied with tobacco and cigarettes by their governments in order to boost their morale.
As smoking-related lung cancer normally takes around twenty years to develop, it was not until the 1930's and 1940's that the increase in lung cancer was noticed, which would tie in with the increase in the uptake of smoking in the earlier part of the century.
Deaths from lung cancer, especially in men, reached their peak at the start of the 80's. However, nowadays the number of deaths from lung cancer in males is beginning to fall, as fewer men are smoking these days. On the other hand, there is an increase in lung cancer deaths in women, as more and more women have taken up smoking and are smoking more heavily than before.
Medical investigations into the cause of lung cancer and the risk factors of developing lung cancer have resulted in the findings that the development of lung cancer is directly related to several factors. Of most importance are the number of cigarettes that a person smokes a day, how many years the person has been smoking and the age that they started to smoke.
Other factors include the frequency of puffs of a cigarette, how deeply the smoke is inhaled and also the exposure to secondhand smoke.
Doctors say that the risk of developing lung cancer increases with the number of packets of cigarettes smoked over time. For example, it is more harmful to a person's health to smoke one packet of cigarettes a day for thirty years than it is to smoke two packets of cigarettes a day for fifteen years. Statistics show that for those people who smoke at least two packets of cigarettes a day, one in seven of them will die of lung cancer.
Undoubtedly, the risk of developing lung cancer will be much higher for someone who has been smoking for longer, however, even if a person has been smoking one packet of cigarettes a day for ten years, they are not without risk of developing any one of a number of smoking-related diseases.
How cancer is caused
Tobacco smoke is made up of around 4,000 harmful substances, chemicals and toxins. Around 60 of them are known to cause cancer. The cancer causing chemicals are mainly found in the tar and when a smoker inhales the smoke from a cigarette, about 70% of the tar stays inside the lungs.
Research that was carried out in the US discovered that benzpyrene, which is a carcinogen found in the tar of cigarette smoke, damages and slowly destroys a certain gene in the body that is responsible for controlling the growth of cancerous cells and preventing the subsequent development of a cancerous tumour. In 60% of lung cancer cases this gene has been seen to be damaged.
When a smoker inhales the tobacco smoke into his lungs, the cells of the lungs will gradually, over time become damaged and destroyed by the chemicals and toxins contained in the tobacco smoke and may eventually develop into cancerous cells because of it.
Other types of cancer that do not have a direct contact with the tobacco smoke, such as cancer of the bladder, pancreas or uterus, form due to the absorption of the carcinogenic substances into the bloodstream, from where they will be transported to other parts of the body and destroy the cells there.
How a tumour forms
In a normal and healthy body new cells are constantly being produced, divided and grown in order for the body to work correctly. New cells are only produced when needed, however, sometimes there is an overload of new cells being produced when new cells are not needed. This can lead to the formation of a tumour, which may be either benign or malignant.
Benign tumours are not harmful unless they are very big in size and they are not cancerous. They develop very slowly and do not spread to other parts of the body.
Malignant tumours, on the other hand, are cancerous and can lead to a person's death if they are not detected in time or if they do not respond to treatment.
The cells inside a malignant tumour are abnormal and they divide and reproduce erratically and uncontrollably. These malignant cells will destroy the surrounding tissue near to the tumour and can separate themselves and spread to other parts of the body, after entering the bloodstream. This is how secondary tumours are formed.
Types of cancer
There are two main types of cancer that may form in the lungs, which can both be developed from smoking. The first is non-small cell lung cancers (NSCLC) and the second is known as small cell lung cancers (SCLC). They are differentiated by the appearance of the tumour and by the rate in which they grow and spread.
The second type, SCLC is found in around 20% of all lungs cancer cases. It is the most aggressive type of cancer and is likely to spread to other parts of the body. Detection of this type of cancer is usually after it has already spread and is in its later stages. This form of lung cancer is strongly related to smoking, although 1% of non-smokers will also develop SCLC.
As mentioned previously, lung cancer or other forms of cancer for that matter, may not be detected until it is already in its later stages and symptoms in the body are beginning to show. Women should have regular smear tests and mammograms in order to check for breast cancer or cervical cancer.
If you are experiencing any of the following symptoms that are common in lung cancer cases, go to your doctor immediately for the necessary tests:
- Constant coughing that won't clear up and that worsens with time
- Coughing up blood
- Wheezing, shortness of breath or a hoarse throat
- Constant chest pains
- Huge weight loss and loss of appetite
- Repeated bronchitis or pneumonia
- Swelling in the neck and face areas
Treatment for cancer
Developing cancer does not necessarily mean death and it does not have to be devastating. If the cancer is caught very early on, the tumour can be fairly easily removed by surgery with very few side effects afterwards.
Treatment for cancer will vary on the type of cancer, the location, the size of the tumour and on the general health of the patient.
If a tumour is not too big, it can be removed through surgery. Usually the surrounding tissues that may contain cancerous cells are also removed, just to make sure and to prevent reoccurrence.
After surgery, patients may or may not receive chemotherapy or radiotherapy, or both as a follow up treatment.
As soon as the body is free of the cancerous cells, a person can go back to leading a normal and healthy life, hopefully without smoking.