Most colon cancers begin as small polyps, detectable through regular cancer screening, such as colonoscopy. Regular screening and removal of polyps can eliminate the risk of colon cancer by up to 90%. Regular screening can also help detect colon cancer early, when it is more treatable.
Symptoms
Many people with colon cancer experience no symptoms in the early stages of the disease. When symptoms appear, they'll likely vary, depending on the size and location in your large intestine. When they do occur, signs and symptoms of colon cancer include:
- Change in bowel habits
- Rectal bleeding or bloody stools
- Persistent abdominal pain or discomfort
- Unexplained weight loss
Causes
Colon cancer occurs when cells in the colon become altered, though the cause of change is often unclear. Most often it begins as a polyp in the colon. Removing polyps before they become cancerous can prevent colon cancer. Other factors that may increase risk of colon cancer include:
- Age – Most people diagnosed are over 45, though it can occur in younger adults
- Race – African-Americans have a greater risk than other races
- IBD – Inflammatory bowel diseases can increase risk
- Lifestyle – Factors like low-fiber diet and sedentary lifestyle may increase risk
Risk Factors
Certain factors can increase your risk for developing colon cancer. You can control some of these risk factors, but you cannot control others.
Risk factors you can change include:
- Being overweight or obese
- Sedentary lifestyle
- A diet high in red meats and processed meats
- Smoking
- Alcohol use
Colorectal cancer risk factors you cannot change include:
- A personal history of colorectal polyps or colorectal cancer
- A personal history of inflammatory bowel disease, including either ulcerative colitis or Crohn’s disease
- A family history of colorectal cancer or adenomatous polyps
- Having an inherited syndrome
- Your racial and ethnic background
- Having type 2 diabetes
Diagnosis
If you are experiencing signs of colon cancer, your doctor may recommend one or more diagnostic tests and procedures. Colonoscopy is the primary method of diagnosing colon cancer. If anything unusual is found, your doctor will take a biopsy for analysis.
Treatment
The type of treatment your doctor recommends will depend largely on the stage of your colon cancer. The three primary options are surgery, chemotherapy and radiation. If the cancer is localized in a polyp and in an early stage, your doctor may be able to remove it entirely. Chemotherapy is usually given after surgery if the cancer has spread.
Digestive Doctor Answers Frequently Asked Questions about Colon Cancer
Our gastroenterologists frequently answer patients’ questions about colon cancer. Here are some of the most common questions and their answers.
What is colorectal cancer?
Colorectal cancer is cancer that starts in the colon or rectum.
How dangerous is colon cancer?
Aside from some types of skin cancer, colon cancer is the third leading cause of cancer-related deaths in the United States, according to the Centers for Disease Control and Prevention (CDC).
How many Americans develop colon cancer each year?
Doctors will diagnose 104,270 new cases of colon cancer and 45,230 new cases of rectal cancer in 2021.
What is my overall risk for developing colon cancer?
If you are a man, your overall risk for developing colon cancer is about 1 in 23, and about 1 in 25 if you are a woman, according to the American Cancer Society.
How can I reduce my risk for developing colon cancer?
You can reduce your risk for developing colon cancer by:
Getting screened for colon cancer – screenings can detect signs of colon cancer before signs and symptoms develop
Eating lots of fruits, vegetables, and whole grains while reducing your intake of red meat and processed meats
Exercising regularly – the American Cancer Society recommends getting 150 to 300 minutes of moderate-intensity or 75 to 150 minutes of vigorous-intensity activity each week, or a combination of moderate or vigorous exercise
Achieving and maintaining a healthy weight – being overweight or obese increases your risk for developing colon cancer and several other types of cancer
Never smoking or quitting smoking – long-time smokers are more likely to develop and die from colon cancer than are people who have never smoked
How often should I be screened for colon cancer?
The U.S. Preventive Services Task Force (USPSTF) recommends adults ages 45 to 75 years with average risk of colon cancer undergo a colon cancer screening using a colonoscopy every 10 years.
