According to the American Cancer Society, there were an estimated 103,170 new cases of colon cancer in the United States in 2012. Globally, colorectal cancer is the third most commonly diagnosed cancer in males and the second most common in females. Approximately 51,690 Americans are expected to die of colon cancer in 2012. In the United States, both the incidence and mortality of colon cancer have been slowly but steadily decreasing.

Age is a major risk factor for colon cancer. Diagnosis before age 40 is very uncommon. African Americans have the highest risk of all ethnic groups in the United States.

Certain genetic disorders are associated with a significant increased risk of developing colon cancer. Familial adenomatous polyposis and Lynch syndrome are the most common hereditary colon cancer syndromes. Together, they account for approximately 5% of all cases. Patients with a personal or family history of colon cancer or adenomatous polyps are also at increased risk.

Inflammatory bowel disease, especially ulcerative colitis is an important risk factor with risk increasing according to extent, duration and activity of disease. Previous abdominal radiation, including patients treated for childhood cancers or men previously treated for prostate cancer, also increases risk. Other conditions that may play a role include obesity, diabetes mellitus, alcohol use, and androgen deprivation therapy.

Most colon cancers arise from preexisting adenomatous polyps. The transformation from benign polyp to a malignant tumor may take several years. Clinical symptoms may include change in bowel habits, melena or hematochezia, abdominal pain, or iron deficiency anemia. Symptoms are typically due to growth of the tumor into the bowel lumen or adjacent structures. Early disease may be largely asymptomatic, which is why successful screening strategies are important. Screening tests include stool for occult blood testing, colonoscopy, flexible sigmoidoscopy, barium enema, or CT colonography.

Staging is performed following diagnosis to establish the local and distant extent of disease spread. The most common staging system used is the American Joint Committee on Cancer (AJCC) TMN system. The TMN system is based on 3 key elements: T (tumor), N (regional lymph nodes), and M (metastasis or spread to distant organs). Once the T, N, and M groups have been assigned, this information is combined to assign an overall stage for the cancer. This process is called stage grouping.

Pathologic stage at diagnosis remains the most important prognostic factor in colon cancer. In general, patients with lower stage cancers tend to have a better outlook for cure or long-term survival. According to the SEER (Surveillance, Epidemiology, and End Results) database for the period between 1991 and 2000, the 5-year survival rates by stage are as follows:

Stage	Survival Rate
I (T1-2 N0)	93%
IIA (T3 N0)	85%
IIB (T4 N0)	72%
IIIA (T1-2 N1)	83%
IIIB (T3-4 N1)	64%
IIIC (N2 disease)	44%

Treatment options depend largely on the stage of disease at diagnosis as well as the age and overall performance status of the patient. Surgery is the mainstay of treatment for early stage disease. Other treatments may include chemotherapy, biologic agents or radiation therapy. Adjuvant treatment is therapy given after complete surgical resection to reduce the risk of disease recurrence.

The Cancer committee decided to look at colon cancer survival rates for stage II and III cases of colon cancer with special focus on adjuvant chemotherapy. There were 158 cases identified in the cancer registry between the years 2005 to 2010. Mean age at diagnosis was 66 and 54% were male versus 46% female. There were 78 cases that were stage II and 79 cases that were stage III. Adjuvant chemotherapy was administered more commonly for stage III disease with an average of 66% of patients having received adjuvant treatment versus 42% of stage II patients. Patients that received adjuvant treatment had improved survival for both stage II (89% versus 76%) and stage III (77% versus 34%) disease. As would be expected, adjuvant treatment had a more dramatic effect on stage III disease.

Survival rates for LGMC were compared to the National Cancer Data Bank for the same period. Overall survival rates by stage were better for LGMC than the national averages. This improved survival was seen in both stage II and stage III patients.

Lafayette General Medical Center