Cancer begins with a change in the structure of DNA. DNA provides our cells with a basic set of instructions, such as when to grow and reproduce.
A change in DNA structure is known as a mutation, and it can alter the instructions that control cell growth. This means that the cells continue to grow instead of stopping when they should. This causes the cells to reproduce in an uncontrollable manner, producing a lump of tissue called a tumour.
Common risk factors
It's not known why and how the DNA inside the cells of the larynx is affected in cases of laryngeal cancer. However, it appears that exposure to anything that can directly damage the cells and tissue of the larynx increases the risk of cancer developing. The most common risk factors for laryngeal cancer are outlined below.
Alcohol and tobacco
Evidence shows that alcohol and tobacco are the two biggest risk factors for laryngeal cancer. Alcohol and tobacco are thought to contain chemicals that affect the normal workings of the cells of the larynx, triggering mutations that can lead to cancer. Drinking alcohol and smoking carry individual risks, but if you do both the risks are greatly increased.
Research has shown that if you smoke 40 cigarettes a day but don't drink alcohol, you're five times more likely to develop laryngeal cancer as well as other cancers of the head and neck, such as mouth cancer, than someone who doesn't drink or smoke.
Similarly, if you don't smoke but drink the equivalent of 30 pints of beer a week, your risk of developing laryngeal cancer is five times that of someone who doesn't drink or smoke.
However, if you smoke more than 40 cigarettes a day and drink an average of 30 pints a week, you're 38 times more likely to develop laryngeal cancer than someone who doesn't drink or smoke.
The fact that only a very small minority of heavy smokers and drinkers develop laryngeal cancer has led researchers to speculate that there must be certain genetic mutations that make people more vulnerable to the harmful effects of alcohol and tobacco smoke.
A number of common genetic mutations have been found in people with laryngeal cancer. It's thought that the genetic mutations disrupt the larynx’s ability to repair itself from the damage caused by tobacco smoke and alcohol.
Human papilloma virus (HPV)
The human papilloma virus (HPV) is the name given to a family of viruses that affect the skin and moist membranes that line the body, such as those in the cervix (neck of the womb), anus, mouth and throat.
Research shows that HPV may increase your risk of getting laryngeal cancer. In one in five cases of laryngeal cancer, HPV DNA was found in cancerous tissue.
HPV is known to cause changes in the cells of the cervix, which can lead to cervical cancer. It's thought that the virus may have a similar effect on the cells of the larynx. HPV is spread during sexual intercourse, including anal and oral sex.
Diet
There's evidence to suggest that a diet high in red meat, processed food and fried food can increase your risk of developing laryngeal cancer.
Occupational exposure
Having a job where you're exposed to high levels of certain substances may also increase your risk of developing laryngeal cancer. These substances include:
- paint fumes
- coal dust
- wood dust
- diesel fumes
- nickel
- formaldehyde – a chemical that's used in a wide range of industrial processes, such as paint manufacturing and cosmetics
- isopropyl alcohol, which is often used as a cleaning solvent
