Colorectal cancer: a review

Colorectal cancer (CCR) is the third most common cancer worldwide in men and women, the second largest cause of death related to cancer, and the main cause of death in gastrointestinal cancer. The risk of developing this cancer is related to bad alimentary habits, smoking, intestinal inflammatory disease, polyps, genetic factors, and aging. Of the patients that are diagnosed with colorectal cancer 90% are older than 50, with a median age of 64 years; however, the disease is more aggressive in patients that are diagnosed at younger ages. According to the American Cancer Association, it was accounted for more than 49,700 deaths in 2015. The goal is to reduce the mortality rate with early diagnosis and treatment. Currently, the survival rate is used to predict a patient’s prognosis. The patient is considered to have a positive familial history if a first-degree relative has been diagnosed with colorectal cancer or colonic polyps before the age of 60, or also if two or more first-degree relatives have been diagnosed with cancer or polyps at any age. There are several methods for detecting colorectal cancer, such as the guaiac test, immunochemical test of stool, DNA stool test, sigmoidoscopy, colonoscopy, and barium enema. The stage in which the cancer is detected determines the prognosis, survival, and treatment of the patient. Provide a review about generalities, genetic basis, risk factors, protective factors, clinical course, diagnostic methods, therapy and survival in colorectal cancer. Conducted research from different databases such as PubMed, Medline, MedScape, on the definition, genetic factors, classification, risk factors, protective factors, diagnostic methods, epidemiology, survival and treatment of colorectal cancer. Articles from 2000 to 2017 were included using the following keywords.