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Colorectal Cancer 133,500 new cancers of the colon and rectum are diagnosed annually, thus, the lifetime probability of an individual developing colorectal cancer is approximately 5 to 6 percent. It is further estimated that 54,900 people will die of their cancer each year, making colorectal cancer the second leading cause of cancer death in this country. There seems to have been a decrease in the incidence and mortality in the last decade, which suggests greater awareness of the disease and improved detection and prevention. Epidemiology and Etiology It is generally accepted that the majority of colorectal cancers arise in a preexisting adenoma and that the risk for cancer increases within the adenoma as the histology of the polyp becomes more villous and the size of the polyp becomes larger. This adenoma to cancer sequence is the basis behind routine colonoscopy with polypectomy as a means to prevent colon cancer. Other factors that are felt to protect against the development of colorectal cancer include a high vegetable fiber intake and Calcium supplementation. In addition, an active life and exposure to sunlight may offer some protection. Lifestyle components that may increase the risk of colon cancer include eating a diet high in fat, alcoholism, and certain styles of food preparation such as deep frying, barbecuing, and smoking. A family history of colorectal cancer markedly increases the risk of colorectal cancer or adenomas in an individual. Other risk factors for the development of colon cancer include inflammatory bowel disease, a personal history of colon polyps or colon cancer, and a personal history of breast cancer. Prognosis: Staging When evaluating prognostic factors, staging remains the most accurate predictor of patient outcome. T stage The depth of colon wall invasion greatly affects the patient's prognosis. Tumor confined to the colonic submucosa (T1) will be associated with metastases in less than 10 % percent of cases. When the muscularis propria is penetrated (T2), the risk of metastases increases to 10 to 20 percent. Full-thickness penetration into the perirectal fat yields a metastatic rate of 33 to 58 percent. N Stage Lymph node metastases in colon cancer patients in an ominous finding which often has a significant negative impact on survival. The number of positive lymph nodes correlates with patient survival. Patients with one to four positive lymph nodes (N1) have survival rates of 50 to 55 percent. The presence of five or more positive lymph nodes (N2) drops survival rates to 22 to 28 percent. Because nodal status is so important to the prognosis of cancer, recent guidelines suggest that the optimal surgical resection include at least 12 lymph nodes for pathological evaluation. Metastatic Cancer (Stage IV) The most common sites of distant metastases were found to be the liver and lungs. The prognosis for stage IV patients is poor, with five-year survival rates around 5 percent. Other Predictors of outcome The histology of the tumor seems to predict outcome. Tumors with poor differentiation, mucin production, and lymphovascular invasion all carry a worse prognosis. Young age at diagnosis was thought to carry a worse prognosis, but not when compared stage for stage. The same holds true for gender and race. Patients who are young or are of nonCaucasian race are usually diagnosed at a later stage and therefore tend to have a worse prognosis. Colon Cancer Cases at Methodist Hospital of Dallas in 2006 There were 99 cases of colon cancer (42 male, 57 female) placed in the tumor registry at MMC in 2006. (Rectal cancers are not included in this discussion as they behave differently than cancers of the colon and recto-sigmoid junction). Of these cases, 86 were diagnosed and began treatment at MMC while the other 13 represented those with recurrent disease as they were diagnosed and underwent the first round of treatment at outside facilities. Demographics: The majority of colon cancer cases occur in patients over the age of 50 with fewer than 10% of cases diagnosed at an age younger than 50. At MMC, 18.7% of the cases (16 patients) of colon cancer were diagnosed in patients younger than 50. Furthermore, colon cancer in the octogenarian also represents a special age group and at MMC 16.3% (14 patients) of the cases were over the age of 80. When race was considered, the majority of patients diagnosed were African American (45.3%) followed by Caucasian (36.1%), Hispanic (16.3%) and asian (2.3%). Stage and Treatment: As mentioned in the introduction, stage of disease is the most accurate predictor of outcome. Of 83 analytical cases in 2006, 1 patient was diagnosed at stage 0, 15 at stage I, 18 at stage II, 33 at stage III, and 16 at stage IV. The remaining 3 cases left the system with an unknown stage of disease The treatment for stage 0, stage I, and stage II disease is often surgery alone. The exception to this includes patients who have some complicating factor such as aggressive histology, obstructive symptoms, or perforation. In the MMC database, All Stage 0 and Stage I patients were treated with surgery only. There was one patient with Stage II disease that received chemotherapy in addition to surgery due to a complicating factor of their disease. Traditionally, all stage III patients should be offered chemotherapy as it has been shown to improve long term survival for stage III disease. At MMC, 27 patients with stage III disease received chemotherapy in addition to surgery, 4 patients had chemotherapy held due to comorbid disease, 1 patient refused chemotherapy, at there is no record of chemotherapy in the remaining patient. The treatment of stage IV disease is often tailored appropriately based on the patients functional status, extent of disease, and resectabilty of the tumor. At MMC 6 Patients with stage IV disease received both chemotherapy and surgery, 5 received surgery alone, 2 received chemotherapy alone, and 3 were referred to hospice and did not receive any specific treatment. Survival: Nation wide, the overall 5 year survival for stage 0, I, and II disease ranges from 80%, 76%, and 63% compared to 50%, 69%, and 44% respectively for the MDMC patients. As expected, the survival significantly drops with metastatic disease, such that nation wide stage III disease has a five year survival of 52% and stage IV survival at five years is only 6%. At MDMC the five year survival at stage III and IV are 44% and 12% respectively. (insert table with comparative data here) Conclusion: Colon cancer is a common malignancy. Patient survival is highly dependant on stage at the initial diagnosis. The patient outcomes at MDMC follow the same trend as the nation wide data, but the true comparison is difficult to make in light of the small number of patients available for comparison.