Epidemiology of colorectal cancer: incidence, mortality, survival rates and risk factors

Colorectal cancer is one of the most common cancers of gastrointestinal tract in Iran and the other parts of the world. Colorectal cancer is the fourth leading cause of cancer death in throughout the world. Almost every year recognizes one million new cases of colorectal cancer that nearly half a million of them die due to this disease.
In this review study, a thorough investigation in Scopus, SID, Google Scholar, Elsevier and PubMed databases was conducted using keywords associated with colorectal cancer including; incidence, prevalence, mortality and survival rates and the risk factors. Then the valid related articles published during the last two decades (1993-2014) were collected and evaluated.
The highest incidence rate of colorectal cancer was related to North America, Australia, New Zealand, Western Europe and Japan. The average incidence rate was related to Southern regions of South America and the lowest incidence rate was related to Africa, South and Central Asia. In Iran, the age-adjusted incidence rate of the disease was differ from 2.34 to 17.62 per 100,000 in Sistan-Baluchestan and Tehran respectively. An upward trend was observed in incidence and mortality rate of the disease in Iran. The survival rate for colorectal cancer in the world and Iran was estimated 13% - 66% and 47% - 50% respectively. The main risk factors for the disease were the high-fat and low-fiber diet, obesity, physical inactivity, smoking, alcohol consumption, family history and age.
Discussion and According to the upward trend in incidence and mortality rate of colorectal cancer in Iran, implementation of cancer prevention programs such as; screening, dietary modification and healthy life style education is necessary.