There will be an estimated 131,600 new cases of colorectal cancer diagnosed with an estimated 56,500 deaths in 1998, accounting for about 10 percent of all cancer deaths. One in 20 Americans will develop colorectal cancer in their lifetime. Other significant risk factors include a personal history of colorectal cancer or polyps, prior diagnosis of endometrial, ovarian or breast cancer and a strong family history of colon cancer.
Colorectal cancer can cause a variety of nonspecific symptoms.
However, most cancers are without symptoms at the early stages, which is why screening is so important. Polyps are abnormal growths of the colon lining, similar to moles on the skin, which are present in 30 percent of individuals at the age of 50 and 55 percent at age 80. The vast majority of colon cancers begin as polyps. A polyp left in place for 20 years has a 20 percent chance of becoming cancerous. Individuals who undergo screening and removal of polyps reduce their risk of developing colorectal cancer by up to 90 percent.