Colorectal Cancer: Epidemiology, Etiology, and Molecular Basis

Colorectal cancer (CRC) is a disease with a major worldwide burden. It is the fourth most frequently diagnosed malignancy in men and third most common in women, with almost one million people developing CRC annually. It was estimated that 147,000 cases were diagnosed in the USA in 2009 and that there were 50,000 deaths from the disease.The worldwide incidence of CRC is increasing; in 1975, the worldwide incidence of CRC was only 500,000.In the time period 1998–2005, the rate of decline accelerated; –2.8 % per year in men and 2.3 % per year in women.