Early detection and the removal of precancerous polyps can prevent the development of more than 50% of colorectal cancers (American College of Gastroenterology 2015).
Screening is an integral part of preventing colorectal cancer. Screening is the process of looking for cancer or precancer in individuals who do not have symptoms of the disease. Physicians recommend that average-risk individuals get screened every 10 years starting at age 50.
Colorectal cancer develops over many years. It can take a polyp 10 to 15 years to develop into cancer. Regular screening can help physicians find and remove polyps before they ever have the chance to develop into cancer. It can also help physicians find …show more content…
Patients who are interested in receiving genetic counseling should visit Genetic Counseling Services or speak with their physician to request a referral.
How Is Colorectal Cancer Diagnosed?
A diagnostic work-up for colorectal cancer may include any number of the following exams or tests:
Medical History and Physical Exam
The physician asks the patient a series of questions about his or her medical history. These questions help the physician identify if the patient has any symptoms or risk factors (including family history) of the disease.
The physician also performs a physical examination of the patient to check the abdomen for suspicious masses or enlarged organs. The physical examination may also include a digital rectal exam (DRE). For this exam, the physician checks the rectum for any suspicious masses using a lubricated, gloved finger. The physician may also check a sample of the patient’s stool for occult blood (blood not visible to the naked eye).
Blood tests are useful for diagnosing colorectal cancer and for monitoring the disease in patients who have already been …show more content…
Microsatellites are short, sequences of DNA that are repeated in a cell. MSI is a change in the number of microsatellites in a cell from the original, inherited number. It is commonly found in colorectal cancers caused by hereditary non-polyposis colon cancer (HNPCC). Knowing MSI is present in a sample can help physicians plan further screening for a patient, as well as notify the patient that his or her relatives may also have HNPCC and be at higher risk of developing colorectal cancer. It should be noted, however, that the presence of MSI in a sample does not necessarily mean a patient has HNPCC.
Several types of imaging tests and procedures are used to diagnose colorectal cancer. A physician may request one or more of the following:
• Computed tomography (CT) scan: A CT scan is the most commonly used imaging test to diagnose colorectal cancer. A CT scan uses x-rays and computer processing to create detailed pictures of areas inside the body. The patient may be given contrast before the test. Contrast can be given orally or intravenously. Oral contrast is a liquid that helps physicians view the intestines. Intravenous contrast helps physicians view the blood vessels and internal organs.
If the physician suspects the cancer may have spread to the liver, he or she may perform a CT scan with portography. This test looks specifically at the portal vein, which is one of two sources that