PREVENTION:

• If ca colon has to be prevented diets rich in fibers and vitamins and low in saturated fats should be advised. Screening for individuals at risk should be done at regular screening intervals. Drugs offering chemoprevention can betried in high risk patients
• Intake of a diet high in fruits and vegetables is protective from colorectal cancer.
• Diet low in red meat, animal fat and/or cholesterol may also be protective.
• If in populations with low average intake of dietary fiber, an approximate doubling of total fiber intake from foods is done, this could reduce the risk of colorectal cancer by 40 percent.
• Other possible protective factors, decreasing the incidence of CRC include folic acid, Vitamin B6, calcium and magnesium
• Postmenopausal hormone use may reduce the risk of colorectal cancer [53].
• If patient is at risk of ca colon, protective effect of aspirin and other nonsteroidal anti-inflammatory drugs on the development of colon cancer is described in various studies. How long-term aspirin or NSAID therapy might protect against colon cancer is not well understood [53]
• HMG-CoA reductase inhibitors (statins) may have a protective effect against several cancers, including colon cancer, although the data are conflicting [54]

TREATMENT
Surgery is the only curative modality for localized colon cancer. In addition, it is often required for diagnosis, staging or palliation of tumor-related obstruction or bleeding [2].
• Once a colon cancer has been detected, prompt preoperative evaluation and treatment is warranted [2].
• A crucial part of this evaluation is to ensure that the patient's entire colon and rectum have been assessed with colonoscopy for the presence of synchronous neoplasms.
• In cases in which the colon cancer prevents the proximal bowel from being examined, colonoscopy should be performed within a few months of the definitive surgery.
• Most patients diagnosed with colon cancer will require an operation.
• Depending on the patient's age and health status, a variety of laboratory, radiologic, and cardiorespiratory tests may be appropriate to assess the patient's operative risk
Preoperative Assessment [2].
• CEA is known to be elevated in a variety of conditions, including colorectal cancer, proximal gastrointestinal cancers, lung and breast cancers, benign inflammatory conditions of the gastrointestinal tract, and smoking. It has never been useful as a screening tool but has proven useful in individuals diagnosed with colorectal cancer.
• Drawing a CEA level has been recommended before and after resection of colorectal cancer [2].
• Postoperative return to normal of an elevated preoperative CEA is associated with complete tumor resection, whereas persistently elevated values indicate the presence of visible or occult residual disease. The interval recommended most commonly is every three months for the first two years. This allows enough time for CEA to return to baseline.
• Elevated preoperative CEA levels have been found to be an independent prognosticator of poor outcome.
• An elevated CEA is associated with future metastases in 37 percent of patients at five years vs. 7.5 percent of patients with normal CEA levels.
• If CEA level is >20 ng/ml before therapy consider a cancer which has already metastasized [62]
• If patient with ca colon has high preoperative carcinoembryonic antigen levels above 15 ng/ml, select patient for adjuvent therapy [62]
• CEA is positive in about 63% of patients having a colorectal carcinoma; about 20% of patient with Dukes A, 28% with Dukes B, 68% with Dukes C.
• In individuals in whom there is a suspicion of invasion of an adjacent organ (because of the presence of a palpable mass, unusual abdominal pain or other symptoms, or unexplained chemical abnormalities), a CT scan may be useful for preoperative planning [2].