The specialist says he needs surgery and likely chemotherapy. Why does he need chemotherapy if they “cut out” the cancer? Colon cancer accounts for 10 to 15 percent of all cancer deaths in North America (McCance & Heuther, 2006). The primary treatment for colon cancer is always surgical (McCance & Heuther; National Comprehensive Cancer Network, 2008). The extent of surgical colon resection depends upon the site of the cancer (McCance & Heuther). Surgical resection of the tumour followed by anastomosis of the bowel with return of normal bowel function is usually successful in patients with early stages of colorectal cancer (Colorectal Cancer Association of Canada (CCAC), 2008). In more advanced stages of colon cancer, where larger sections of bowel must be removed, anastomosis of the bowel may not be possible, thus resulting in a necessary colostomy (CCAC, 2008). Following surgical resection of the tumour, chemotherapy is often used as adjuvant treatment in an attempt to reduce the possibility of cancer metastasis and recurrence (CCAC; McCance & Heuther). How will the surgeon and oncologist decide on a chemo regime for him? Many patients like Mr. C who undergo surgery for colon cancer also take chemotherapy afterwards to reduce the chance of the cancer returning. Mr. C’s surgeon and oncologist will decide upon a chemotherapy regime for him depending upon the pathological results of the tumour resection (National Cancer Institute, 2008). The term chemotherapy refers to the treatment of disease using cytotoxic drugs that target vital cellular activity necessary for normal and abnormal cellular growth (McCance & Heuther, 2006). For chemotherapy to be curative, enough tumour cells must be killed such that the body’s immune system can destroy any remaining cancerous cells (McCance & Heather). Although single chemotherapeutic agents can be used in the treatment of colon cancer, combination therapy may be selected due to synergistic effects of multiple chemotherapeutic drugs, and to combat the development of single drug resistance (CCAC, 2008; McCance & Heuther). Some common chemotherapeutic agents recommended by the Colorectal Cancer Association of Canada used for both single and combination therapy are 5-fluorouracil, folinic acid, capecitabine, irinotecan, and oxaliplatin (2008). Furthermore, the chemotherapy regimen in based upon the principle of dose intensity. The “principle of dose intensity implies there is a direct correlation between the dose of a chemotherapeutic agent and killing of tumour cells” (McCance & Heuther, 2006, p. 389-90). Therefore, increased doses of chemotherapy are associated with increased cellular death of both normal and abnormal cells. As chemotherapy is toxic to all cells, it is important to recognize the therapeutic index of chemotherapeutic agents. The “therapeutic index denotes the relative effective dose needed to kill cancer cells as compared to the dose that would be harmful to normal cells” (McCance & Heuther). The therapeutic index of chemotherapy drugs is relatively narrow, and therefore, is an important factor to consider in the dosing of chemotherapeutic agents (McCance & Heuther). What do they mean by “staging” of his cancer? Cancer stage refers to the extent or severity of the cancer based upon location of the primary tumour, tumour size, number of tumours, and presence of lymph node involvement (National Cancer Institute, 2008). In general, there are four levels of tumour staging: Stage 1: Cancer is confined to the organ of origin. Stage 2: Cancer is locally invasive. Stage 3: Cancer has spread to regional structures (i.e. lymph nodes). Stage 4: Cancer has spread to distant sites (i.e. the cancer has metastasized). For example, the liver and lungs are common sites of colorectal metastases (McCance & Heuther, 2006, p. 384). In addition, many types of cancer have their own unique staging classification. For example, colorectal cancer is staged using the Dukes classification system (McCance & Heuther, 2006). The Dukes classification system is as follows: Stage A: Cancer is limited to the bowel wall. Stage B: Cancer extending through the bowel wall. Stage C: Nodal metastases regardless of extension into the bowel wall. Stage D: Distant metastases regardless of primary size. (McCance & Heuther, 2006, p. 1433). Staging is not to be confused with tumour grading. Tumour grading is a system used to classify cancer cells in terms of how abnormal they look under a microscope, and how quickly the tumour is likely to grow and spread (National Cancer Institute, 2008). Therefore, grading predicts the potential for tumour growth, whereas staging is the current extent of tumour existence/spread. Internationally, the World Health Organization has standardized the staging of cancer by the TNM system: T is for tumour spread, N is for node involvement, and M is the presence of distant metastases (McCance & Heuther, 2006; National Comprehensive Cancer Network, 2008). Long term prognosis for cure and survival generally “declines with increasing tumour size, lymph node involvement, and metastasis” (McCance & Heuther, p. 384). Tumour staging and grading may influence the choice of therapy depending upon the invasiveness and spread of the cancer (National Comprehensive Cancer Network). Simply stated, highly invasive cancer requires highly aggressive treatment. ~Paige Okkema and Sarah Stauffer References McCance, K.L., & Huether, S. E. (2006). Pathophysiology: The biologic basis for disease in adults and children. Elsevier Mosby: St. Louis. Colorectal Cancer Association of Canada. (2008). Treating Colorectal Cancer: Treatment options for colorectal cancer. Retrieved May 20, 2008, from www.colorectal-cancer.ca/en/treating-cancer. National Cancer Institute. (2008). Tumour Grade: Questions and answers. Retrieved May 20, 2008, from www.cancer.gov/cancertopics. National Comprehensive Cancer Network. (2008). Colon and Rectal Cancer: Treatment guidelines for practice. Retrieved May 20, 2008, from www.ncnn.org/patients.