Our experts can usually cure rectal cancer if it is found early enough. But the more rectal cancer grows, the more difficult it can be to treat.
- For people with an average risk who have no symptoms, MSK’s doctors recommend regular screening tests for colorectal cancer starting at age 45.
- People at a higher risk may benefit from earlier, more frequent screenings.
- At any age, if you are worried about symptoms and wonder if you should talk to your doctor about colorectal screening, it’s a conversation worth having.
- While there are many types of colorectal cancer screening tests, colonoscopy is the only test that can find polyps and remove them. This means that a colonoscopy can both find and prevent colon cancer.
Today, more than 60 percent of people age 50 to 75 are regularly screened for the disease.
Doctors are detecting colon and rectal cancer more often and at an earlier stage, when it’s most treatable. In fact, 90 percent of people with rectal cancer live five years or more after treatment if the cancer is found and removed at an early stage.
- What is the average risk of rectal cancer?
- What is an increased risk of rectal cancer?
- What should I know about rectal cancer if I am under 45?
- What should I know about family history and the genetic causes of rectal cancer?
- What if I have been treated for cancer before?
- What is a colonoscopy?
- What is a flexible sigmoidoscopy?
- What is a virtual colonoscopy?
- What is a fecal occult blood test?
- What is a fecal immunochemical test?
- What is genetic testing for colorectal cancer?
MSK’s screening guidelines for rectal cancer are based on your risk and factors specific to you. These include your age, personal and family medical history, and genetics.
If you are age 45 or older, you are at an average risk of rectal cancer if you have the following:
- no symptoms
- no personal or family history of colorectal cancer or precancerous polyps (noncancerous growths in the inside surface of the colon or rectum)
- no personal history of inflammatory bowel disease, such as ulcerative colitis or Crohn’s colitis
If you have an increased risk of rectal cancer, discuss with your doctor if you should have earlier, more frequent screenings.
You are at an increased risk if you have one of the following:
- a personal history of colorectal cancer or precancerous polyps.
- a family history of a first-degree relative (such as a parent or sibling) who had cancer or a precancerous polyp in the colon or rectum before age 50, or multiple family members with colorectal cancer or polyps.
- a personal history of long-standing (more than eight years) inflammatory bowel disease, such as ulcerative colitis or Crohn’s colitis.
- a family history of familial adenomatous polyposis (FAP). This condition is a rare form of hereditary colorectal cancer. FAP can lead to the development of hundreds or thousands of polyps in the colon and rectum at a very early age. If left untreated, people with FAP will almost always develop colorectal cancer by age 40.
- a family history of Lynch syndrome (formerly known as hereditary nonpolyposis colorectal cancer). This condition is caused by mutations in specific genes. It accounts for approximately 2 to 3 percent of all colorectal cancer diagnoses.
Real progress is being made against rectal cancer, as more people are screened and treatment options improve. But in recent years there has been a disturbing rise in rectal cancer diagnoses in people under 50. MSK doctors and scientists are working to find out what’s behind this troubling trend. MSK has established the first center focused on people with colorectal cancer under 50.
If you are worried about symptoms, do not ignore them — tell your doctor.Back to top
If you have more than one family member with colon or rectal cancer, or if you have a family member with early-onset colorectal cancer (before age 50), your care team can help determine if you may be at risk of an underlying hereditary condition that makes you more likely to develop cancer. If your care team feels that you may be at risk, we can refer you to our Clinical Genetics Service for further evaluation and customized screening options.Back to top
You may have an increased risk of colorectal cancer if you’ve had therapy for another type of cancer. Your care team may recommend more frequent screenings.Back to top
At MSK, a colonoscopy is the preferred colorectal cancer screening method.
A colonoscopy is a test in which a thin, flexible tube with a light and a video camera on its tip is placed in your colon and rectum to search for polyps. It’s the most effective way to find them. Your care team will prescribe a clear-liquid diet and medication to clear out your bowel during the 24 hours before the test. You’ll be sedated during the exam. Your doctor can usually remove any polyps that are detected, which then go to a pathologist (a doctor who specializes in diagnosing disease) for examination and analysis.Back to top
A flexible sigmoidoscopy is similar to a colonoscopy. The main difference is that your doctor uses a shorter tube to examine the rectum and the lower part of your colon.Back to top
A virtual colonoscopy (VC) is also known as a CT colonography. VC is an alternate screening option for some people. A radiologist uses CT scans to create 2-D and 3-D images of the rectum. It does not require sedation. VC has limitations, however. For example, it requires the same preparation as a conventional colonoscopy: a clear-liquid diet and medication to clear out the rectum and colon. In addition, if VC detects a polyp or other abnormality in the rectum or colon, you may need a colonoscopy to remove it. VC can sometimes miss small or flat polyps.Back to top
Because colon or rectal bleeding can be a sign of colorectal cancer, a fecal (stool) occult blood test may detect small amounts of blood in your stool that are not otherwise visible. The test works like this: For three consecutive days, you’ll place small stool samples on chemically treated cards. You’ll send those cards to a lab for testing. During this time, you have to follow a special diet to ensure that the test results are accurate. If an abnormality is detected, you may need to have a colonoscopy to remove it.Back to top
A fecal immunochemical test (FIT) screens for colorectal cancer by detecting blood in the stool. Unlike a fecal occult blood test, you don’t have to follow a special diet beforehand. FIT reacts to a part of the hemoglobin molecule (a protein found in red blood cells). If an abnormality is detected, you may need to have a colonoscopy to remove it. FIT is also called an immunochemical fecal occult blood test.Back to top
If your doctor finds multiple polyps during a colonoscopy, it may be a sign that you have a hereditary syndrome that increases your risk of developing colorectal cancer. About 5 to 10 percent of colorectal cancer is due to changes in the genes that may be passed from parents to children. Our Clinical Genetics Service offers counseling and education about the risk of hereditary forms of colorectal cancer, as well as genetic testing for you and your family members.
During genetic testing, we may take a sample of your blood or tissue from a polyp or tumor (if you already have rectal cancer). We’ll look at the sample for changes in your genes that are associated with hereditary syndromes that cause rectal cancer. If we discover a mutation, your care team will determine which condition you have. Knowing about genetic changes can affect your treatment.
Doctors’ knowledge of genetic mutations continues to increase rapidly. Sometimes we may find a mutation that we don’t yet understand but that still might put you at a higher risk of hereditary cancer. If this happens, our counselors may recommend that you and your family members have screening more often.
Lynch syndrome (formerly known as hereditary nonpolyposis colorectal cancer) is associated with an increased risk of colon and rectal cancer, as well as endometrial, ovarian, gastric, urinary tract, brain, and pancreatic cancers. Lynch syndrome is the most common form of hereditary colorectal cancer. It is responsible for about 3 percent of all colon and rectal cancer.
Familial Adenomatous Polyposis
Familial adenomatous polyposis (FAP) consists of many precancerous polyps — possibly hundreds or thousands — in the colon and rectum. In a milder form of FAP, there may be a smaller number of colorectal polyps.
MYH-associated polyposis is marked by multiple precancerous polyps in the colon and rectum, similar in number to that seen in the milder form of FAP.
Hyperplastic Polyposis Syndrome
In hyperplastic polyposis syndrome (HPS), multiple hyperplastic polyps develop in the colon and rectum. Currently, there is no gene mutation known to be associated with HPS.