COLON CANCER
In 2015, there were an estimated 132,700 new cases of colorectal cancer and nearly 50,000 deaths related to colorectal cancer.
In the United States, colorectal cancer is the third most common cancer and the second leading cause of cancer related deaths. The incidence of colorectal cancer varies by state, and in Louisiana the incidence rate is slightly higher than the national average.
Colorectal cancer is a form of cancer that originates in the colon or rectum, which are parts of the digestive system known as the large intestine. The most common form of colorectal cancer is adenocarcinoma.
This type of cancer begins in cells of the intestine that release mucus and other fluids. It is believed that most colorectal cancers begin as small growths known as polyps.
Over time, these polyps undergo a number of changes to transform into a cancer. Some risk factors for the development of colorectal cancer include: increasing age, personal or family history of colorectal polyps, excessive alcohol use, smoking, obesity, a sedentary lifestyle, a history of Crohn’s or ulcerative colitis and certain genetic mutations.
Symptoms of a possible colorectal cancer may include blood in the stool, a change in bowel habits such as thinning of the stools or new onset of diarrhea or constipation, abdominal pain, unintentional or unexplained weight loss, anemia, urgency or the sensation of incomplete evacuation of a bowel movement.
Often, an early cancer will present without any symptoms.
In order to diagnose colorectal cancer at an early stage when it is very treatable, it is recommended that all individuals above the age of 50 undergo screening.
The primary purpose of screening is to diagnose a cancer before it is symptomatic and to prevent the development of cancer by removing polyps before they have the opportunity to degenerate into a cancer. Physicians can screen patients for colorectal cancer in four ways:
1. Fecal occult blood test. This is a test that looks for microscopic blood in patient’s stool. This test may erroneously be positive under certain circumstances (i.e., consumption of certain foods) and does not tell the physician where the blood is coming from.
2. Barium enema. For this examination, contrast material is injected into the rectum and colon, and X-rays are taken. The contrast allows irregularities in the wall of the color or rectum to be seen.
The drawbacks of this test are that small polyps may be missed by this examination, and when abnormalities are found, it requires follow up with a colonoscopy.
3. Sigmoidoscopy. The last third of the large intestine is called the sigmoid colon. A sigmoidoscopy allows the physician the ability to look at the mucosa of the sigmoid colon and rectum using a flexible tube with a camera at its end. Since only one third of the colon is being examined, abnormalities in the more proximal two thirds of the colon are not diagnosed.
4. Colonoscopy. The colonoscope is a flexible tube with a camera similar to the sigmoidoscope. It allows examination of the entire large intestine and as well as the last part of the small intestine. It also provides the physician the ability to remove small polyps or sample the intestinal mucosa for further analysis by a pathologist. A colonoscopy is the gold standard for colorectal cancer screening.
The prognosis and treatment of colorectal cancer varies depending on the stage of disease at the time of diagnosis. Generally, the primary treatment is surgery to remove the segment of colon or rectum with cancer. Very few colon cancer patients require a colostomy. Depending on the stage of the cancer, chemotherapy – the infusion of drugs to kill cancer – may be used to in addition to surgery. For low rectal cancer and some advanced colon cancers, radiation therapy may be indicated.
Currently, there is no way to prevent polyps or colorectal cancer, but simple lifestyle changes may reduce your risk:
1. Eat plenty of fruits, vegetables and whole grains.
2. Drink alcohol in moderation. 3. Stop smoking. 4. Exercise for at least 30 minutes most days of the week.
5. Maintain a healthy weight. 6. Most importantly, get screened for colorectal cancer beginning at age 50.
Over the last decade the incidence of colorectal cancer has been steadily declining.
This decline is thought to be the direct result of improved screening practices with colonoscopy.
With appropriate screening with colonoscopy, many colorectal cancers can be prevented.
Unfortunately, only 61 percent of Louisianans receive appropriate screening. If you’re 50 years old or older, colorectal cancer screening could save your life.
Dr. Gabriela Vargas is a colorectal surgeon and clinical assistant professor of surgery at LSU Health Shreveport.
