Cancer is a disease in which cells grow out of control and invade, erode, and destroy normal tissue.

        There are many causes of cancer. However, usually there is more than one cause, which will cause cancer. This is known as being multi-factorial.

        Carcinogens are one major cause known to produce cancer. Carcinogens are dangerous as some are highly reactive molecules that target DNA. These are known as mutagens. These carcinogens can cause errors, duplication or rearrangement in DNA sequences that contribute to the progression of cancer. An example of a carcinogen is tobacco. Tobacco smoke contains at least twenty carcinogens, which are known to cause lung cancer.

        Age can be a factor when asked what causes cancer. This is because cancer becomes more common as we get older. 85% of cancers are diagnosed in patients over fifty-five. This is because as we get older we become more susceptible to some types of carcinogens. Age is also a cause as it takes a long time for a cell to become cancerous, as there has to be a number of changes to the genes within a cell, before it turns into a cancerous cell. Therefore the longer we live; the more time there is for us to become susceptible to these mistakes in our genes.

        Our genetics are also another cause of cancer. If we are born with one of these genetic mutations, which can cause cancer, we are said to be genetically predipositional. This is known as many of the genes that control cell growth, and DNA repair are associated with inherited cancer susceptibility. The genes, which are susceptible to leading to cancerous mutations, are called proto-oncogenes.  They are called oncogens as the word “onco” means cancer. An example of this is the faulty genes, BRCA1 and BRCA2. If a woman carries one of these genes, she is at a higher risk of developing breast cancer.

        Our overall lifestyle can act as a risk factor. Smoking is the principle cause of lung cancer due to its high content of carcinogenic. However our diet can also be a principle cause of some cancers. It is thought that foods, such as fats, meat and drinks, such as alcohol, are risk factors for cancer, whereas fibre, vitamins, and some types of oils that are found in fish, are protective against cancer. However, the effect of our diet on the actual risk of cancer is not actually fully known. This is because as time changes, new information’s found out to show that some parts of a diet can be classed as a carcinogen. An example of this is some years ago saccharin claimed to be a carcinogen, but now is said not to be as dangerous as we expected. Lastly our views on sun exposure are a known cause for non- melanoma and melanoma skin cancer. Melanomas one of the most deadly skin cancers, and are located in the upper part of the skin. These start commonly to form a mole, which then turn to become cancerous. These types of skin cancers are associated with ultraviolet waves caused by sunlight. This is most common in people who are predisposed to sunburn rather than tan. However, even though this predisposition to ultraviolet rays has been known to cause skin cancer, people still do not take notice of this warning.