This week we will continue with the theme of discussing cancers. This week’s article will focus on a common and lethal cancer, colorectal cancer which is often referred to as colon cancer in short. In the United States of America up to 153 000 cases of cancer of the colon and rectum are diagnosed annually. This is either symptomatic patients or patients who are picked up through routine screening. Unfortunately, local prevalence data is lacking, however there is evidence that this cancer is on the rise.
Colon cancer is very uncommon before the age of 40. Cases rise sharply between the ages of 40 to 50 years. A family history of colon cancer is also a strong risk factor for developing this cancer. Other risk factors include conditions such as ulcerative colitis and Chron diseases that causes inflammation of the bowel. Individuals who have received Abdo pelvic radiation are also at risk of developing colon cancer.
They are certain factors which have been shown to be protective and lower the risk of developing colorectal cancer. These include but not limited to; increased physical activity, a diet high in fruits, vegetables, fiber, calcium and vitamin D, consumption of coffee and use of drugs such as aspirin and NSAIDs.
The commonest symptom for colon cancer is a change in bowel habits. Some individuals may have alternating diarrhoea with constipation. They may be fresh blood in the stools. They may be abdominal pain or a feeling of an abdominal mass. This is often accompanied by nonspecific symptoms such as fever, loss of weight and a poor appetite. Other individuals can present as an emergency with intestinal obstruction or perforation and severe bleeding.
The diagnostic test of choice for colon cancer is a colonoscopy. A colonoscopy is a procedure whereby a flexible camera in a tube is inserted via the anus to visualize the rectum and the colon. If a mass is visualized then a biopsy is done, whereby small pieces of this masses are obtained and take for diagnostic testing to confirm the cancer. Other tests that can also be done include CT colonography, blood tests to assess for complications and other blood tests known as tumor markers can also be done.
Surgical removal is the only curative modality for localized colon cancer. Post-surgery patients should receive postoperative chemotherapy to reduce the risk of recurrence and to increase cure rates. Patients who present when the disease has already spread are not candidates for surgery and receive palliative chemotherapy instead.