What are the risk factors for cancer?
Some cancers, particularly in adults, have been associated with certain risk factors. A risk factor is anything that may increase a person's chance of developing a disease. A risk factor does not necessarily cause the disease, but it may make the body less resistant to it. Persons who have an increased risk of developing cancer can help to protect themselves by scheduling regular screenings and check-ups with their physician and avoiding certain risk factors. Cancer treatment has been proven to be more effective when the cancer is detected early. The following risk factors and mechanisms have been proposed as contributing to the development of cancer:
Lifestyle and environmental factors such as smoking, high-fat diet, exposure to ultraviolet light (UV radiation from the sun), or exposure to chemicals (cancer-causing substances) in the work place over long periods of time may be risk factors for some adult cancers. Most children with cancer, however, are too young to have been exposed to these lifestyle factors for any extended time.
Family history, inheritance, and genetics may play an important role in some adult and childhood cancers. It is possible for cancer of varying forms to be present more than once in a family. Some gene alterations are inherited. However, this does not necessary mean that the person will develop cancer. It indicates that the chance of developing cancer increases. It is unknown in these circumstances if the disease is caused by a genetic mutation, other factors, or simply coincidence.
Exposures to certain viruses, such as the human papillomavirus (HPV) and human immunodeficiency virus (HIV; the virus that causes acquired immune deficiency, or AIDS), and the herpes virus have been linked to an increased risk of developing certain types of cancers. Possibly, the virus alters a cell in some way. That cell then reproduces an altered cell and, eventually, these alterations become a cancer cell that reproduces more cancer cells. Cancer is not contagious and a person cannot contract cancer from another person who has the disease.
Environmental exposures such as pesticides, fertilizers, and power lines have been researched for a direct link to childhood cancers. There has been evidence of cancer occurring among non-related children in certain neighborhoods and/or cities. Whether prenatal or infant exposure to these agents causes cancer, or whether it is a coincidence, is unknown.