English Across the Curriculum
Scientists do not really know why cancer cells start to grow. They sometimes lose their ability to control their own growth. This is because DNA may be damaged. Doctors, however, have found out that there are many factors that cause cancer. Many forms of cancer are caused by our environment. For example, if you expose yourself to the sun’s rays without any protection for too long, chances of getting skin cancer will become higher.
Smoking cigarettes can cause lung cancer or other diseases over a certain time. Being in close contact with chemicals may also increase the risk of getting cancer.
Other types of cancer are not caused by our environment. They come from our genetic material. We inherit it from our parents or grandparents.