Aren’t there other tests that could detect colon cancer? The thought of a colonoscopy makes me nervous.
Why does a colonoscopy detect more cancers than other methods?
What is a polyp?
How frequently are polyps cancerous?
What about a family history of colon polyps…does that change anything?
Here is what the American Cancer Society writes about the familial link to colon cancer:
About 30 percent of people who develop colorectal cancer have disease that is familial. People who have a strong family history of colorectal cancer (as defined above), especially if the relatives are affected before the age of 60, are considered at increased risk of developing this disease. People with a family history of colorectal cancer need to talk with their doctor about beginning colorectal cancer testing before the age of 50.
About another 10 percent of people who develop colorectal cancer have an inherited genetic susceptibility to the disease. Approximately three to five percent of colorectal cancers are associated with the inherited colorectal cancer syndrome, called hereditary non-polyposis colorectal cancer (HNPCC), or Lynch syndrome. Another one percent of colorectal cancer cases are associated with the inherited syndrome, called familial adenomatous polyposis (FAP).
Familial adenomatous polyposis (FAP) is a disease where people typically develop hundreds of polyps in their colon and rectum. Usually this occurs between the ages of five and 40. Cancer usually develops in one or more of these polyps beginning at age 20. By age 40, almost all people with this disorder will have developed cancer if preventive surgery is not done. FAP is sometimes associated with Gardner syndrome, a condition that involves benign (noncancerous) tumors of the skin, soft connective tissue and bones. About one percent of all colorectal cancers are due to FAP.
Hereditary nonpolyposis colon cancer (HNPCC) is another clearly defined genetic syndrome. It accounts for three to five percent of all colorectal cancers. This syndrome also develops when people are relatively young. These people have polyps, but they only have a few, not hundreds as in FAP. Women with this condition also have a very high risk of developing cancer of the endometrium (lining of the upper part of the uterus). Other cancers associated with HNPCC include cancer of the ovary, stomach, small bowel, pancreas, kidney, ureters (tubes that carry urine from the kidneys to the bladder) and bile duct.
Doctors have found that most families with HNPCC have certain characteristics:
These are called the Amsterdam criteria. If any of these hold true for your family, then you might want to seek genetic counseling. But even if your family history satisfies the Amsterdam criteria, it doesn’t mean you have HNPCC. Only about 60 percent of families who have the Amsterdam criteria have HNPCC. The other 40 percent do not; and although their colorectal cancer rate is higher than normal (about two times), it is not as high as that of people with HNPCC (about six times).
A second set of criteria for HNPCC, which has been recently revised, is called the Bethesda criteria. These are used to determine whether a person with colorectal cancer should have their cancer tested for genetic changes called microsatellite instability (MSI). These criteria include at least one of the following:
MSI testing is the first step in laboratory testing to identify people with HNPCC. If a patient meets Bethesda criteria and has a tumor with MSI, more genetic testing will be needed to confirm that there is a mutation of one of the HNPCC genes. Still, the majority of people who meet the Bethesda criteria do not have HNPCC. On the other hand, about two percent of people with colorectal cancer who do not meet any of these criteria still have HNPCC when they are tested.
Doctors should also be suspicious of HNPCC if, instead of colorectal cancer, the family members have other cancers associated with this gene mutation. These are endometrial cancers, ovarian cancers, small bowel cancers, or cancer of the lining of the kidney or the ureters. Still, one family member younger than age 50 must have been diagnosed with colorectal cancer before a diagnosis of HNPCC is considered.
Accurate identification of families with these inherited syndromes is important. Then doctors can recommend specific measures, such as screening and other preventive measures, at an early age. Because several types of cancer can be associated with inherited colorectal cancer syndromes, all people should check their family medical history for polyps or any type of cancer. Those who develop polyps or cancer should inform other family members. People with a family history of colorectal polyps or cancer should consider genetic counseling, to review their family medical tree and determine whether genetic testing may be right for them. This will help them to make decisions about getting screened and treated at an early age.
Besides colon polyps, is there anything else that might increase my risk of colon cancer?
Tell me more about inflammatory bowel disease and increased risk. What is the connection?
Are men at higher risk than women for developing colon cancer?
Why is age so important in screening for colorectal cancer?
What are the risks for women?
Does race affect colorectal cancer screening recommendations?
How is a colonoscopy done?
How do I prepare for a colonoscopy?
Why is early detection so important?
Early detection and treatment is therefore essential to a patient’s outcome.
What are the colon cancer risk factors?
Can you explain more about each type of screening test for colorectal cancer?
Is there anything I should be looking for to report to my doctor that might indicate a need for earlier screening or screening out of the expected interval of every ten years?
How can I contact the Digestive Disease Center to schedule an appointment?
I live alone and don’t have anyone to drive me to the test. What can I do?
Contact Us for more information Maps & Directions
Employee E-mail Log-in