COLORECTAL CARCINOMA –A REVIEW

Abstract: Colorectal cancer (CRC) is a common and lethal disease.The third most common cancer both in male and female is colorectal cancer (CRC) worldwide. In India, it is the fourth most common cause of cancer in males and third most common cause of cancer in females. The agestandardized rates of CRC in India havebeen estimated to be 4.2 and 3.2/100,000 formales and females, respectively, compared to 35.3 and 25.7, respectively, in the USA.It is estimated thatapproximately 149,500 newcases of largebowel cancer are diagnosed annually inthe UnitedStates, of which approximately 104,270 arise from colon and the remainder from the rectum..Approximately 52,980 Americans are expected to die of large bowel cancer each year. However, the incidence of CRC is increasing inyoung age especially indeveloping countries, which ismainly contributed by change inlifestyle and food habits.Although CRC mortality has been progressivelydeclining since 1990, at a current rateof approximately 1.6 to2.0 percent peryear , it still remains the third most common cause of cancer deathin the United States in women and thesecondleading cause of death inmen.In contrastto these declines, the incidence of CRC in men andwomen under the ageof 50 steadily increased at arate of 2.1 percent per yearfrom 1992 through 2012 and has continued toincrease since then . Theseincreases are driven predominantly by left-sidedcancers in general and rectal cancer in particular (3.9 percent per year) . Current literatures suggests that over 86 percent of those diagnosed under the age of 50 are symptomatic at diagnosis, and this is associated with more advanced stage at diagnosis and pooreroutcomes .At present, most guidelines suggest initiating screening at the age of 50 unlessindividuals haveinammatory bowel disease,a historyof abdominal radiation, apositive family history, or a predisposing inherited syndrome.CRC is diagnosed after the onset of symptoms, or through screening colonoscopy or fecal occult blood testing in the majority of patients. Screening of asymptomatic individuals for CRC is advocated by major societies and preventive care organizations. Screeninghas been shown todetect asymptomatic early stagemalignancy and improve mortality. However, while compliance with CRCscreening guidelines is steadily improving,it isstill relatively low.