• Acutely bleeding colon cancers that require emergent resection should be removed following the same principles as in elective resection
Staging of Colon Cancer [2].
• Colon cancers should be staged using the Primary Tumor, Regional Lymph Nodes, Distant Metastasis (TNM) staging system
• To be properly evaluated, one should strive to have a minimum of 15 lymph nodes examined microscopically.

Adjuvant Therapy [2].
• Postoperative adjuvant systemic chemotherapy has a proven benefit in Stage III colon cancer and may be beneficial in certain high risk Stage II patients
• Patients with Stage III colon cancer are recognized to be at high risk for recurrence, and administration of 5-fluorouracil (5-FU)/leucovorin for six months postoperatively has proven benefit in decreasing recurrence and improving survival.
• Standard therapy for metastatic colon cancer is CPT11 (irinotecan) plus 5-FU/leucovorin, also known as the Saltz regimen. In 2005, the standard therapy for metastatic colorectal cancer is IFL plus bevacizumab (irinotecan, 5-FU, leucovorin, Avastin).
o Each of the agents in the Saltz regimen is administered by IV injection weekly for 4 weeks every 6 weeks.
o Diarrhea is the most commonly encountered adverse effect with this regimen. Other adverse effects include mucositis, neutropenia, hair loss, and skin hypersensitivity reactions. The combination of 5-FU/leucovorin/CPT11 has the potential for severe toxicity, mainly diarrhea leading to dehydration and vascular collapse, in some patients. Many clinicians start therapy with an approximately 25% decrease in doses of CPT11 (100 mg/m2 rather than 125 mg/m2) and 5-FU (400 mg/m2 rather than 500 mg/m2) and escalate to full doses only if the initial cycle of treatment is well tolerated.
• The addition of levamisole does not seem to add any benefit. The addition of interferon alpha-2a does not improve disease-free survival or overall survival, but does increase toxicity.
• Patients with Stage II colon cancer who are considered at higher risk for recurrence include those with one or more of the following characteristics: tumor perforation, adherence, or invasion of adjacent organs; nondiploidy by flow cytometry; poorly differentiated tumor; or venous, lymphatic, and perineural invasion. It may be advantageous for these patients to receive adjuvant chemotherapy. Ideally, this should be performed within the confines of a clinical trial.
• The value of immunotherapy for colon cancer is undetermined. Its use is recommended within the setting of a clinical trial
• Intraperitoneal and intraportal infusions of chemotherapy are recommended only in the confines of a clinical trial
• Intrahepatic chemotherapy for colon cancer with liver metastasis is intra-arterial floxuridine (FUDR) [55].
o Following resection of the primary colon cancer and lymph nodes, 2 options for chemotherapy exist: systemic chemotherapy with a standard regimen such as 5-FU/leucovorin/CPT11 or intrahepatic (intraarterial) chemotherapy with FUDR.
o The second option is worth considering for patients with large or multiple liver lesions because this route results in delivery of a higher dose of chemotherapy to the liver metastases. The underlying principle is that liver metastases derive their blood supply primarily through the hepatic arterial circulation, whereas normal liver derives most of its blood supply through the portal vein.
o The major adverse effect of intra-arterial FUDR is sclerosing cholangitis, which may be quite severe and may necessitate discontinuation of therapy. [2].
• Palliative chemotherapy for patients with metastatic colorectal cancer aims to improve survival and quality of life. Resection of metastatic disease (hepatic or pulmonary metastases) can lead to 5-year survival rates of 35-58%. About 15% of patients with liver metastases initially judged to be unresectable will become resectable after systemic chemotherapy, with excellent long-term survival [22]
• Radiation is rarely used in the treatment of colon cancer. Radiation's potential for injury to the abdominal viscera limits its usefulness
• Patients with rectal cancer must be referred for radiation oncology consultation. Radiation has been demonstrated to reduce the risk of local recurrence of rectal cancer following surgical resection. Thus, in the adjuvant setting, the therapy for rectal cancer includes combination of radiation and chemotherapy. This is a basic difference between the therapy of colon cancer and rectal cancer [2].

SURVEILLANCE
• Coordinate physician visits every 3 to 6 months for the first 3 years, every 6 months during years 4 and 5, and subsequently at the discretion of the physician after treatment of colorectal carcinoma [57].
• Physician visits should focus on the initial risk assessment, followed by the implementation of a surveillance strategy and periodic counseling based on estimated risk and feasibility of surgical interventions like hepatic resection [57].
• For patients at lower risk of recurrence (stages I and Ia) or those with co morbidities impairing future surgery, only visits yearly or when symptoms occur are recommended [58]
• For patients at lower risk of recurrence (stages I and Ia) should have a colonoscopy before or within 6 months of initial surgery, repeated yearly if villous or tubular adenomas >1 cm are found; otherwise, repeat every 3 to 5 years [58]
• Postoperative serum CEA, CEA every 3-6 mo for 2 y, then every 6 mo for a total of 5 y for T2 or greater lesions, if the patient is a candidate for surgery or systemic therapy [56]
• Since fluorouracil-based therapy may falsely elevate CEA values, waiting until adjuvant treatment is finished to initiate surveillance is advised [57].
• If serial CEA level is increasing advise physical examination, colonoscopy and CT chest, abdomen and pelvis [56]
• If findings are negative consider PET scan and reevaluate chest/ abdominal/pelvic CT in 3 months [56]
• If metachronous tumor is documented treat accordingly [56]
• Routine blood tests (i.e., complete blood counts or liver function tests) are not recommended for surveillance [57].
• Periodic fecal occult blood testing or X Ray chest is not recommended [57].
• Patients who are at higher risk of recurrence, and who could be candidates for curative-intent surgery, should undergo annual CT of the chest and abdomen for 3 years after primary therapy for colon and rectal cancer [57].
• A pelvic CT scan should be considered for rectal cancer surveillance, especially for patients who have not been treated with radiotherapy
• All patients with colon and rectal cancer should have a colonoscopy for the pre- or perioperative documentation of a cancer- and polyp-free colon. Following the surgical treatment of colorectal cancer, a colonoscopy in 1 y: If abnormal, repeat in 1 y. If negative for polyps, repeat in 3 y, then every 5 y. If no preoperative colonoscopy due to obstructing lesion, colonoscopy in 3-6 months should be done [57]
• For patients of rectal cancer who have not received pelvic radiation, flexible sigmoidoscopy of the rectum every 6 months for 5 years is recommended [57].