ABSTRACT
Colorectal cancer (CRC) is the third most commonly malignant neoplasm occurring worldwide (1) and one of the most common cancers in the UK after breast and lung cancer, with approximately 40,000 new cases registered each year (2). In 2019, there will be an estimated 101,420 new cases of colon cancer and 44,180 new cases of rectal cancer diagnosed in the US. The American Cancer Society suggests that lifetime risk of developing colorectal cancer is about 1 in 22 (4.49%) for men and 1 in 24 (4.15%) for women (3). In the UK, the lifetime risk of developing colorectal cancer is 1 in 18 in males and 1 in 20 in females; in 2006 there were 15,957 deaths from colorectal cancer (2). In the US, colorectal cancer is the third leading cause of cancer-related deaths in men and in women and the second most common cause of cancer deaths when men and women are combined. It is expected to cause about 51,020 deaths during 2019 (3). Risk factors for colorectal cancer include genetic predisposition, previous history of polyps, chronic inflammation, physical inactivity, obesity, a diet of red meat, smoking, and excess alcohol consumption. Although the incidence of colorectal cancer has increased steadily over many decades, recent trends have shown a reduction in mortality believed to be due to screening, improved chemotherapy, and surgery (4).
