In addition, many of the approximately one million skin cancers that are diagnosed each year could be prevented by protection from the sun's rays. Screening examinations, conducted regularly by a health care professional can result in the detection of cancers of the breast, colon, rectum, cervix, prostate, testis, tongue, mouth, and skin, at earlier stages when treatment is more likely to be successful. The nine screening-accessible cancers listed above account for approximately half of all new cancer cases. By surgery, radiation, chemotherapy, hormones, and immunotherapy. Since the occurrence of cancer increases as individuals age, most cases affect adults middle-aged or older.
Cancer researchers use the word risk in different ways.
In the United States, for example, men have a 1 in 2 lifetime risk of developing cancer, and for women the risk is 1 in 3. It compares the risk of developing cancer in persons with a certain exposure or trait to the risk in persons who do not have this exposure or trait. This means that smokers are about 10 times more likely to develop lung cancer than non-smokers are. Most relative risks are not that large. The National Cancer Institute estimates that approximately eight million Americans alive today have a history of cancer.