Smoking: Causation and Acceleration of Cancers
One of the most prevalent, and well-known, issues related to smoking is the development of cancer. While smoking is related to everything from emphysema to cardiovascular disease and stroke, cancer is the most dreaded side effect of smoking.
While lung cancer is the most often cited as being related to smoking, there are other cancers which may be caused or promoted by tobacco products.
Smoking Changes DNA
A New Cause for Concern
“Smoking causes changes to DNA” is the conclusion of a new study out from an international team of scientists. The researchers have uncovered evidence that smoking a pack a day can cause irreparable and potentially fatal changes to your DNA.
The study found that the appearance of mutations in cancer cells depend on how much contact that particular part of the body has with cigarette smoke. This causal relation puts the lungs at a particular disadvantage.
While the lungs bear the brunt of a pack-a-day smoking habit, other organs can also undergo mutations from smoking a pack a day. Among them are:
- 23 mutations per cell in parts of the mouth
- 97 mutations in the larynx
- 37 in the throat
- 150 in the lungs
The presence of these mutations could only mean one thing. Researchers surmised that the higher some mutations in a particular organ, the higher the chance that these mutations would lead to the creation of cancer cells.
Prof Sir Mike Stratton, one of the co-lead authors, put the findings in layman’s terms, when he said, “The more mutations there are, the higher the chance that these will occur in the key genes that we call cancer genes, which convert a normal cell into a cancer cell.”
An Invisible Change
One of the more revelatory discoveries of the study was how genetic mutations could occur even in non-smokers. Almost 13.8% of non-smokers (either people who passively smoke or are exposed to secondhand smoke) showed incidences of mutation in the same places where heavy smokers have the same changes in their cells.
So even a passing relationship with tobacco can cause irreversible damage to your DNA. The permanency of the damage to DNA cells was another conclusion reached by the study. Once specific signatures in an organ cell change, they never change back.
Other organs not in direct contact with cigarette smoke, like the liver or gallbladder, also underwent genetic mutations brought on by smoking. But whether these mutations were natural or related to smoking was not determined.
Lung Cancer Causation and Acceleration
According to the DNA Learning Center, lung cancer is the number one cause of cancer death in the United States. Even more shocking is the fact that lung cancer is also almost entirely preventable. Nearly all cases are among those who smoke. Those non-smokers who develop lung cancer are usually those live or work closely with smokers and are exposed to secondhand smoke. It is rare for those who are never exposed to tobacco smoke to develop lung cancer (although not impossible).
When smoke is inhaled, it is more than just the smoke itself that causes damage. Tobacco smoke contains over 7,000 chemicals, many of which are known carcinogens. That means they have been shown to cause cell mutation, which is one way cancer develops. The abnormal cells begin to regenerate out of control and eventually crowd out healthy cells.
Each drag on a cigarette promotes damage to the lungs as smoke and tar are inhaled. While the lungs are relatively resilient, they eventually become bogged down with tar, mucus (products to try and clear contaminants out of the lungs), and chemicals. This reduces oxygen inhalation into the body and damages the cells throughout, including those in the lungs.
Lung cancer is especially lethal because it is often not detected until its later stages. Many symptoms of lung cancer, including prolonged cough and shortness of breath, are mistaken for other, less severe, illnesses. This leads to a delay in seeking medical intervention.
Other Cancers Accelerated By Smoking
While the most prevalent, lung cancer is not the only cancer linked to smoking. Many others may be caused, directly or indirectly, by tobacco use. Still others may be accelerated in those who smoke tobacco products.
Based on studies reported by Oncogene, pancreatic cancer is accelerated in those who smoke tobacco products. This means that it grows at a faster rate, and also that it may spread to other areas of the body faster in those who use tobacco products. Pancreatic cancer is one of the most lethal malignancies, with a five-year survival rate of only 6%. Smoking may decrease the survival rate even more.
According to Cancer.gov, cervical cancer is more common in women who smoke tobacco products. While this cancer has a relatively high survival rate compared to other cancers, due in large part to yearly pap screenings, treatment for cervical cancer is often painful, and it may hinder a woman’s ability to have children.
Throat and Mouth Cancers
Cancers of the esophagus, mouth, throat, and voice box are also common in those who smoke, as well as in those who use chew tobacco. This shows that it is the tobacco itself, as well as the smoke, that causes issues. In smokers, these cancers are more common due to the smoke inhalation which passes through the throat and mouth frequently. Smoke may settle on the sensitive tissues of the esophagus, drying it and coating it with chemicals. In those who chew tobacco, chemicals found in the “tobacco spit” drips down the throat and is often held in the mouth for long periods of time. Carcinogens found in the tobacco may alter cell growth. This proves that there is no safe tobacco product.
Other cancers linked to smoking include bladder cancer, cancers of the kidneys and liver, as well as certain types of leukemia. Additional cancers may be linked to smoking, as more research is being done to determine all of the ways in which tobacco usage is deadly.
Prevention of Cancer
The only true means of prevention of lung cancer is to avoid cigarette smoke. This includes smoking tobacco products, as well as being around those who smoke. Other cancers may have additional prevention methods, but smoking is a primary risk factor and should be discontinued. Those who are addicted to tobacco may employ the use of various aids, such as nicotine replacement products.
More Information about Causation and Acceleration of Cancers
Read more about the effects cigarette smoke has on the human body at The Effects of Smoking.