According to the American Cancer Society, colon cancer is one of the leading causes of cancer-related deaths in the United States. However, proper screening and early diagnosis can lead to improved treatment outcomes.
Almost all colon cancer starts in glands in the lining of the colon and rectum. Although the exact cause of colon cancer is uncertain, many begin as benign polyps, which develop slowly into cancer. Learn more about colon polyps below.
Diagnosis of Colon Cancer
With proper screening, colon cancer can be detected before symptoms develop, when it is most curable.
A fecal occult blood test (FOBT) may detect small amounts of blood in the stool, which could suggest colon cancer. However, this test is often negative in patients with colon cancer. For this reason, an FOBT must be done along with imaging tests to screen and potentially diagnose colon cancer.
Tests include colonoscopy, which views the entire colon and is the best screening test for colon cancer, and sigmoidoscopy. Your doctor may also do blood tests, including a complete blood count (CBC) and liver function tests.
Colon Cancer Prevention & Risk Factors
While nothing guarantees that you don't develop cancer, there are steps you can take to reduce your risk and stay healthy.
- Make healthy food choices
- Eat foods high in fiber - Try to increase the amount of fiber in your diet to between 20 and 30 grams daily. High-fiber foods include whole grains, fruits and vegetables.
- Limit processed foods, sweets and salt.
- Avoid foods high in saturated fats
- Eat 5 of more servings of fruits and vegetables daily.
- Choose foods rich in omega-3 fatty acids.
- Don't overeat. Watch portion size and calories.
- Limit sweets.
- Limit alcohol consumption. Limit the amount of alcohol - wine, beer or mixed drinks - to less than one drink per day, or avoid it completely.
- Maintain a healthy weight.
- Engage in regular physical activity, preferably 45 to 60 minutes five days per week.
- Don't smoke.
- Get regular check-ups and talk to your doctor about regular cancer screenings.
High levels of HDL, or “good,” cholesterol.
An HDL level of 60 mg/dl or higher has been shown to be best for heart health. And a study in the journal Gut found that levels of about 70.4 mg/dl also decreased the risk for colon cancer compared with levels below 45 mg/dl.
Taking drugs like aspirin or ibuprofen daily or weekly was linked to lower cancer risk, found a study in The American Journal of Gastroenterology. People with an inherited form of the disease benefited the most.
Men and women who ate yogurt daily were less likely to develop colon cancer than those who ate none, report findings in the International Journal of Cancer.
Watching what you eat
Women who say they pay no attention to their diet – eating anything at any time – are more likely to develop colon cancer than those who don’t report this behavior.
More Research Needed
Much more research is needed before these methods are widely recommended. Some are already known to be good for your heart, such as increasing good cholesterol and keeping your weight under control.
However, others have side effects. For instance, aspirin or ibuprofen can contribute to ulcers and stomach bleeding and this risk may outweigh the benefits, so talk with your doctor before making changes to your habits.
Colon cancer can develop for a variety of reasons. Talk to your doctor about your risk.
- Age - Most colon cancers are diagnosed in men or women over age 50. Colon cancer affects both men and women.
- Family history - Your risk may increase if you have a parent, sibling or child with colon cancer or colon polyps.
- Personal history - If you've had colon cancer or adenomatous polyps (benign but may be precursor to colon cancer), your risk increases.
- Inflammatory intestinal conditions - Conditions like ulcerative colitis and Crohn's disease, when the colon is inflamed over a period of time, can increase your risk.
- Genetics - Inherited genetic syndromes can increase susceptibility to colon cancer at a younger age. Familial adenomatous polyposis (FAP) - a disease that causes development of thousands of polyps in the colon and rectal lining - and hereditary nonpolyposis colon cancer (HNPCC) - also called Lynch syndrome - are two such genetic syndromes that can be detected through genetic testing.
- Diabetes - Diabetics have an increased risk for developing colon cancer.
- Diet - A diet high in red meats, processed meats or fats - especially from animal sources - can increase your risk.
- Alcohol consumption - Heavy use of alcohol may increase your risk.
- Obesity - People who are obese have an increased risk of developing colon cancer and an increased risk of dying from it.
- Sedentary lifestyle - Physical inactivity increases your risk.
Screenings Save Lives
In the meantime, scientists do know that at least six of every 10 colon cancer deaths could be prevented if all adults ages 50 and older were screened for the disease. Most men and women should get periodic screening tests, such as a colonoscopy, beginning at age 50. Ask your doctor about the best screening test and schedule for you.
Time For a Colonoscopy?
Use Memorial Hermann's Direct Access program through ScheduleNow to schedule your colonoscopy appointment online.
Colon Cancer Treatment
Colon cancer starts in the large intestine or the rectum, the end of the colon. Treatment of colon cancer usually includes surgery.
Surgical procedures for colon cancer include:
- Fulguration, the use of an electric current to burn away the tumor using a special tool
- Cryosurgery, in which an instrument is used to freeze and destroy the abnormal tissue
- Radiofrequency ablation, which uses a special probe with tiny electrodes that release high-energy radio waves to kill the cancer cells
- Resection, which is surgery to remove part or all of the organ containing the cancer.
Chemotherapy is the standard treatment for locally advanced cancers, in which the tumor has grown into nearby blood vessels and other tissues, but has not spread to the liver or distant organs.
We use the most advanced radiation therapy technology to help patients fight cancer with less scarring, shorter recovery times and a quicker return to productivity.
Clinical Trials and Research
As a teaching hospital affiliated with The University of Texas Health Science Center at Houston (UTHealth) Medical School, Memorial Hermann-Texas Medical Center offers access to innovative treatments and technologies as soon as they are made available, whether in the development and testing phases, or after FDA approval. Patients who qualify also have the opportunity to participate in clinical trials of treatments that would not otherwise be available to them.
Colon Polyps - Harmful?
Colon polyps usually are harmless. However, when colon cancer does occur, it most often starts as a polyp that becomes malignant over time. So polyps are sometimes cause for concern.
What are Polyps?
Polyps are extra tissue that grow on the lining of the large intestine or colon. Most cause no symptoms. But occasionally, they may lead to constipation or diarrhea lasting longer than a week, or bleeding.
Sometimes, polyps grow larger over time. Fortunately, most polyps aren't dangerous. But some polyps do eventually grow into colon cancer.
Who is At Risk for Developing Polyps?
Those older than age 50 face a much higher risk of developing polyps than younger people. And having a polyp increases your risk of having others. You also may face a heightened risk for polyps if you have a family history of polyps or colon cancer. Other factors that might raise risk include eating a lot of fatty foods, smoking, drinking alcohol, being overweight and lack of exercise.
Screening for Polyps
Doctors remove all polyps and test them for cancer. Experts advise everyone ages 50 and older to be tested for colon cancer and colon polyps. If you have a family history of colon polyps or colon cancer, your doctor may recommend earlier screening.
Research suggests that 90 percent of colon cancers can be prevented. In addition to having screenings and getting any polyps tested, these healthy habits may help protect you:
- Eat five or more servings of fruits and vegetables a day.
- If you eat red meat, limit yourself to 3 ounces daily.
- Exercise every day.
- Maintain a healthy weight.
- Don't smoke.
- Avoid or limit alcohol.