What is colorectal cancer?
Among cancers that affect both men and women, colorectal cancer (cancer of the large intestine or large bowel) is the second leading cause of death due to cancer in the United States. Despite this, many people don’t know what colorectal cancer is, who is at risk or how you can prevent it.
What is colorectal cancer?
Colorectal cancer is cancer that happens in the colon or rectum, as previously mentioned, also known as the large bowel or large intestine. Often it is just called colon cancer, for short. The drawing shows the colon. AKA large intestine or large bowel. The rectum is the passageway that connects the colon to the anus.
Sometimes abnormal benign growths, called polyps, form in the colon or rectum. Over time, some polyps may turn into cancer. There are screening test that can check for polyps so they can be removed before they turn into cancer. Screening can also help find colorectal cancer at an early stage. If colorectal cancer is found and treated at an early stage it often leads to a cure. This has arguably been one of the great advances in the prevention of colon cancer.
Who is at risk for colorectal cancer?
The risk getting colorectal cancer increases as you get older. More than 90% of cases of colorectal cancer are in people who are 50 years old or older. Thus, it is recommended that persons over the age of 50 get checked for colon cancer, even if they have no symptoms.
There are other risk factors for colorectal cancer, such as:
• Inflammatory bowel disease such as Crohn’s disease or ulcerative colitis.
• A personal or family history of colorectal cancer or colorectal polyps.
• A genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).
Lifestyle factors may also contribute to an increased risk of colorectal cancer. These factors include:
• Not participating in regular physical activity
• A diet low in fruit and vegetables
• A low-fiber and high-fat diet
• Being overweight or obese
• Alcohol consumption
• Tobacco use
What are the symptoms of colorectal cancer?
Colorectal polyps and colorectal cancer don't always cause symptoms, especially at first. Someone could have polyps or colorectal cancer and not know it. That is why getting checked regularly for colorectal cancer even if there are no symptoms is so important. We call checking persons without symptoms for colorectal cancer screening.
If you have symptoms, they may include:
• Blood in or on your stool when you have a bowel movement
• Stomach pain, aches, or cramps that don’t go away
• Unexplained weight loss
If you have any of these symptoms, talk to your doctor. These symptoms could be caused by something other than cancer. The only way to know what is causing them is to see your doctor.
What can you do to reduce your risk of colorectal cancer?
As previously mentioned, almost all colorectal cancers begin as precancerous polyps (benign but abnormal growths) in the colon or rectum. These polyps can be present in the colon for years before invasive cancer develops. Usually they cause no symptoms. Colorectal cancer screening can find precancerous polyps so they can be removed before they turn into cancer. Screening can also find colorectal cancer early, when there is a greater chance that treatment will be most effective and lead to a cure.
Research is underway to find out if changes to your diet can reduce your colorectal cancer risk. Also, researchers are examining the role of certain medicines and supplements in preventing colorectal cancer.
Some studies suggest that people may reduce their risk of developing colorectal cancer by increasing physical activity, limiting alcohol consumption, and avoiding tobacco.
Overall, the most effective way to reduce your risk of colorectal cancer is by having regular colorectal cancer screening tests beginning at age 50. Other persons with higher risk of colorectal cancer need to begin screening before age 50, usually planned with a gastroenterologist.
When Should I Get Screened?
You should begin screening for colorectal cancer soon after turning 50. You should also continue getting screened at regular intervals, usually 5 to 10 years if there are no findings on screening, and 3 to 5 years if pre-cancerous polyps are found and removed.
You may need to be tested earlier than 50 if:
• You or a close relative have had colorectal polyps or colorectal cancer.
• You have an inflammatory bowel disease such as Crohn’s disease or ulcerative colitis.
• You have a genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).
Speak with your doctor about when you should begin screening and how often you should be tested.