When doctors find colorectal cancer early, it’s highly curable. It happens when abnormal cells grow in the lining of the large intestine (also called the colon) or rectum. This is a common cancer in both men and women. It has the second highest rate of cancer deaths in the U.S.
What Are Polyps?
Colorectal cancers often start out as polyps -- harmless growths on the inside of the intestines. The two most common types of intestinal polyps are adenomas and hyperplastic polyps. They form when there are problems with the way cells grow and repair the lining of the colon. Most polyps stay harmless, but some can turn cancerous. Removing them early prevents the disease.
Risk Factors You Can't Control
Your risk of colorectal cancer depends on your family history and lifestyle. Things you can't control include:
Age -- most people with it are older than 50
Polyps or inflammatory bowel disease
Family history of colorectal cancer
History of ovarian or breast cancer
Risk Factors You Can Control
You can control some things that raise the risk of colorectal cancer. Try to avoid these:
Diet high in red or processed meats, or those cooked at high temperatures
Obesity (having too much fat around the waist)
Not exercising enough
Heavy alcohol use
What Are the Symptoms?
Colorectal cancer doesn’t have early warning signs, so it's important to get screened. Finding it early means it's more curable. As the disease gets worse, you may see blood in your stool or have pain in your belly, a change in bowel habits (like constipation or diarrhea), unexplained weight loss, or fatigue. By the time these symptoms appear, tumors tend to be bigger and harder to treat.
Tests that Find Colorectal Cancer
Screening tests are key to finding it early. Starting at age 50, most people should have a colonoscopy every 10 years. This test uses a tube with a tiny camera to look at the whole colon and rectum. It not only finds tumors early, but can also prevent colorectal cancer by removing polyps (shown here).
One type of colonoscopy uses a CT scan to show a 3-D model of your colon. Called virtual colonoscopy, the test can show polyps or other problems without actually placing a camera inside your body. The main disadvantage is that if your doctor finds polyps, you would still need a real colonoscopy to take them out. Your doctor may suggest you have the virtual kind once every 5 years.
Barium enema X-rays allow your doctor a glimpse at the inside of the colon and rectum. It’s another way to find polyps, tumors, or other changes in your intestines. Seen here is an X-ray that shows an "apple core" tumor blocking the colon. Like in a virtual colonoscopy, doctors follow up any abnormalities with a regular colonoscopy. Your doctor may suggest you have a barium enema once every five years.
Instead of a colonoscopy, your doctor may recommend flexible sigmoidoscopy. This test uses a slender tube to look inside your rectum and the bottom part of your colon. The tube has a light and a camera and shows polyps and cancer. If your doctor says this is the right test for you, you should get one every 5 years.
Fecal Blood Tests
The fecal occult blood test and fecal immunochemical test can show whether you have blood in your stool, which can be a sign of cancer. You give samples of your stool to the doctor to study. You may have one of these tests in the years that you don’t have a colonoscopy or sigmoidoscopy. If your doctor says one of the fecal blood tests is right for you, you should take it every year.
An At-Home Choice: DNA Test
A new test called Cologuard looks for blood or suspicious DNA in your stool sample. The test is very accurate at finding colon cancer, but if it does, you still need to follow up with a colonoscopy. Cologuard can’t take the place of a colonoscopy, and it’s so new that the U.S. Preventive Services Task Force doesn’t have guidelines for it yet. A doctor can write a prescription for Cologuard in most U.S. states.
The Right Diagnosis
If a test shows a possible tumor, the next step is a biopsy. During the colonoscopy, your doctor takes out polyps and gets tissue samples from any parts of the colon that look suspicious. Experts study the tissue under a microscope to see whether or not it is cancerous. Shown here is a color-enhanced, magnified view of colon cancer cells.
The Stages of Colorectal Cancer
Experts "stage" any cancers they find -- a process to see how far the cancer has spread. Higher stages mean you have a more serious case of cancer. Tumor size doesn’t always make a difference. Staging also helps your doctor decide what type of treatment you get.
Stage 0 -- Cancer is only in the innermost lining of the colon or rectum.
Stage I -- Cancer has grown into the muscle layer of the colon or rectum.
Stage II -- Cancer has grown into or through the outermost layer of the colon or rectum.
Stage III -- Cancer has spread to one or more lymph nodes in the area.
Stage IV -- Cancer has spread to other parts of the body, such as the liver, lung, or bones.
The outlook for your recovery depends on the stage of your cancer. The “5-year survival rate” means the percentage of people who live 5 years or more after being diagnosed. Stage I has a 74% 5-year survival rate, while stage IV has a 5-year survival rate of only 6%.
Can Surgery Help Me?
Surgery has a very high cure rate in the early stages of colorectal cancer. In all but the last stage, doctors remove the tumors and surrounding tissue. If they are big, your doctor may need to take out an entire piece of your colon or rectum. If the cancer affects your liver, lungs, or other organs, surgery probably won’t cure you. But it may help reduce your symptoms.
Fighting Advanced Cancer
Colorectal cancer can still sometimes be cured even if it has spread to your lymph nodes (stage III). Treatment typically involves surgery, radiation (shown here), and chemotherapy. If the cancer comes back or spreads to other organs, it will probably be harder to cure. But radiation and chemotherapy may still reduce symptoms and help you live longer.
Will Chemo Make Me Feel Bad?
Newer chemotherapy drugs are less likely to make you sick. There are also medicines that can help you control your nausea.
Radiofrequency ablation (RFA) uses intense heat to burn away tumors. Guided by a CT scan, a doctor inserts a needle-like device into a tumor and the surrounding area. RFA can destroy some tumors that can’t be surgically removed, like in the liver. Chemotherapy can work with RFA.
Prevent Colorectal Cancer With Diet
You can take steps to dramatically lower your odds of getting colorectal cancer. Eat a nutritious diet, get enough exercise, and control your body fat. Those habits prevent 45% of colorectal cancers. The American Cancer Society recommends a diet heavy on fruits and vegetables, light on processed and red meat, and with whole grains instead of refined grains. That will help you keep a healthy weight.
Prevent Cancer With Exercise
Adults who stay active seem to have a powerful weapon against colorectal cancer. In one study, the most active people were 24% less likely to have the cancer than the least active. It didn't matter whether what they did was work or play. The American Cancer Society recommends exercising 5 or more days a week for at least 30 minutes a day. Vigorous exercise gives you even more benefits in less time -- 20 minutes 3 or 4 days a week.
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.