**1. Introduction**

**Incidence of Colorectal Cancer:** Colorectal cancer (CRC) is the third most common neoplasm worldwide. According to the International Agency for Research on Cancer (IARC), approximately 1.24 million new cases of CRC were detected worldwide in 2008 (Ferlay, et al, 2008). It is the third most common cancer in men (10.0% of the total) and the second commonest in women (9.4% of the total) worldwide. IARC data have shown that more than half of all CRC cases occur in the developed regions of the world i.e. Europe, America and Japan (Ferlay, et al, 2008). In the European Union (EU27) alone 334,000 new cases of CRC were detected in 2008 and approximately 38,000 people were diagnosed with CRC in the UK alone (National UK Statistics). The incidence of CRC is on rise in Europe, particularly in southern and Eastern Europe, where rates were originally lower than in Western Europe (Coleman, et al, 1993 & Bray, et al, 2004). Contrary to the current trend in Europe, the incidence rate of CRC in the USA has fallen in the last two decades (NCI-SEER, 2006). Epidemiological studies have identified that a rapid trend of 'Westernization', with change in diet and life style has resulted in increased incidence rates of CRC in developing countries (Marchand, et al, 1999, Flood, et al, 2000, Boyle, et al, 2008, & Ferlay, et al, 2010). The occurrence of CRC is strongly related to age, with nearly 80% of cases arising in people who are 60 years or older, although there has been a recent increase in incidence in people younger than 60. The lifetime risk for developing CRC in men is 1 in 16 whereas in women it is 1 in 20 (National Statistics, UK).
