Cancer is a malignant disease that is caused by the uncontrolled division of body cells. To begin with cancer may be localized, but it progresses by spreading to other body parts. There are no typical cancer symptoms and very often they do not appear until the late stages.
Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer. Cancer is one of the major causes of death in countries across the world. However,  many of those cases could be prevented--whether by giving up smoking, changing diet, avoiding infectious diseases or by national screening programs.

Traditionally, the practice of cancer prevention has been viewed as a general public health effort, similar to the prevention of infectious diseases such as polio or small pox. According to this paradigm, cancer prevention interventions should be delivered to the general population to completely eradicate the disease. Although this is certainly a laudable goal, total eradication of cancer has not been possible to date. In addition, such a global strategy may not be possible given the many different types of cancer, the myriad causes of cancer, and the potential toxicity of preventive strategies. The practice of applying cancer preventive interventions to the general population would be feasible only if the intervention was extremely safe, well tolerated, and acceptable to most healthy individuals. Unfortunately, few preventive strategies that have been found to reduce cancer incidence meet these stringent requirements.

Dietary and behavioral interventions would seem to be particularly safe and effective ways to reduce cancer risk. The most obvious and clearly beneficial of these are smoking cessation programs. However, it has been difficult to show that other dietary and behavioral interventions effectively reduce the risk of cancer; this may be for several reasons. First, altering one's dietary and behavioral practices is particularly difficult, and may require intensive and prolonged behavioral modification. Second, because the carcinogenic effects of a particular diet or behavior are often lifelong, intervention in adulthood may not be effective. Third, many clinical trials in which dietary or behavioral strategies have been tested have not been found to effectively reduce cancer or precancerous lesions , although several large dietary intervention cancer prevention clinical trials are currently ongoing.

Cancer Check
Cancer is often diagnosed by chance, sometimes during a routine check.  A simple blood test can help to diagnose cancers such as those affecting blood cells.  Sometimes the presence of specific biochemical 'cancer markers' can detect cancer, while in other cases, a Karyotype can help . When cancer is suspected, a biopsy of the affected part could help to confirm its presence.

Earlier it was thought that cancer is incurable.  But innumerable studies in the recent past have helped to understand that cancer could occur due to a person's life style and that a lot can be done to actually prevent the disease.
Go for regular health check ups if you have a family history of cancer, if you belong to a high - risk group or if you are above the age of forty years. Regular screening helps early detection and treatment of cancers, such as those of the breast or colon.