Colorectal carcinoma increases with aging and 94% of them occur after 6th decade. Five-year survival rate in the localized lesion has shown to be 91% in colonic and 84% in rectal carcinoma, while decreased to 60% and 50% respectively in the
carcinoma
with regional infiltration. Digital rectal examination, fecal occult blood test and sigmoidoscopy have been proven as effective screening tools to detect early or precancerous lesion, and sigmoidoscopy could be recommendable after 6th decade.
Screening
in the moderate risk group needs to meet several requirement, E.g., non-invasiveness, good compliance, low false-positive and false-negative with good predictability, and costs lower than expense in treating advanced carcinoma. The American
Cancer
Society recommends to begin annual digital re ctal examination and fecal occult blood testing at age forty, and flexible sigmoidoscopic examination every three or five year after two normal annual examinations at age fifty. This guideline can be
also
effective and applicable in Korean population considering recent increase in colorectal carcinoma, though the beginning of screening may be delayed for five or ten years later. Screening in the high risk group must be performed as a regular base
considering respective prevalence and risk in the family members.
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