What is the best choice for colon cancer screening and when should it be done?
Colorectal cancer (CRC) is the second biggest cause of cancer-related deaths in the United States, and the incidence rate is increasing, particularly among adults aged 20 to 49. Unfortunately, only about 30% of eligible adults in the United States have been examined for CRC.
Screening tests that look for cancer or precancerous growths called colon polyps can help avoid colon cancer.
When is the best time to begin screening?
For average-risk people, the United States Preventative Services Task Force recommends commencing CRC screening at the age of 45. These recommendations are based on the most recent information on when the risk of colon cancer begins to rise.
Patients at average risk have no personal or family history of colon cancer, nor do they have a genetic disease that raises their risk of getting CRC. As a result, patients should discuss their family history with their primary care physician, including all cancer diagnoses in blood relatives, so that the optimal time to start colon cancer screening may be determined.
Which type of screening should you go with?
The most crucial aspect of colon cancer screening is having a test performed. Colonoscopy or FIT testing are the most popular procedures to screen for colon cancer in most patients. If you can't or don't want to have a colonoscopy or FIT testing, there are other choices to think about. Finally, this is a personal and essential decision that a patient should address with their healthcare professional so that the appropriate test can be performed at the appropriate time.
It is recommended that high-risk people undergo screening before the age of 45. A primary care physician can help identify when and how a patient should be checked for CRC if they are concerned about their risk level. Patients with a history of CRC or polyps, a first-degree relative with CRC or advanced polyps (those that would have progressed to CRC if not removed), a family history of certain genetic syndromes, or a history of inflammatory bowel disease (such as Crohn's disease or ulcerative colitis) are all high-risk factors.
What screening options are available for CRC?
Colonoscopy: Colonoscopy is the gold standard of screening tests, detecting about 95% of CRC cases. It's also the only way for a gastroenterologist to discover and remove potentially malignant colon polyps at the same time. Although colonoscopies are generally low-risk procedures, they can include a minor risk of bleeding and perforation, which increases with age.
Prior to the operation, patients should drink a colonoscopy prep, which washes stool out of the colon so that it may be adequately examined during the procedure. The gastroenterologist's office provides the prescription instructions for the prep.
To ensure that the patient is as comfortable as possible, the procedure is usually performed under anaesthesia. It's vital to note that patients aren't put under general anaesthesia, but they usually feel tired and relaxed throughout the procedure.
A gastroenterologist will put a colonoscopy, a flexible tube with a camera at the end, into the rectum during a colonoscopy. The colon is then thoroughly examined. If no polyps are found and the colon has been adequately prepared (cleanout), a repeat colonoscopy is recommended in 10 years. This period will be shorter if polyps are discovered, or if the patient's risk level or symptoms change.
The faecal immunochemical test (FIT) is a laboratory test that searches for blood in the faeces. Patients collect their faeces with a kit and then scrape them with a probe, which is then placed in a tube and mailed to the lab. Every year, FIT testing is conducted. A disadvantage of FIT testing is that it has a false positive rate of about 5%. With a 79 per cent accuracy rate, it can effectively rule out CRC. For many people, FIT testing is a viable alternative to a colonoscopy because it is non-invasive, convenient, and cost-effective. If a stool test results in a positive result, a colonoscopy is required to determine the cause of the positive result.
Flexible sigmoidoscopy: The rectum and lower part of the colon are examined using a flexible tube with a camera. This treatment has the advantage of being faster than a colonoscopy (just 5 to 15 minutes) and requiring less aggressive laxative medicines. If no polyps are found, individuals usually have a flexible sigmoidoscopy every five years. Because this test does not scan the entire colon, it is unable to detect malignancies or polyps in the areas that have not been investigated. It can detect 70 per cent of tumours and polyps at best. If an anomaly is discovered, a second colonoscopy will be required to examine the entire colon.
CT colonography: A CT scan is utilized to view the rectum and the entire colon. Patients must take laxative drugs the night before a colonoscopy, just as they would for a colonoscopy. To achieve clear photos, a tiny tube is inserted into the rectum to stretch the colon. Patients who cannot tolerate anaesthesia or who have other medical issues that prevent them from undergoing a colonoscopy may benefit from this test. Radiation exposure and the discovery of unrelated anomalies beyond the colon, which might lead to needless investigations, are two disadvantages of CT colonography. While CT colonography is 86.7 per cent accurate at detecting specific polyps, it is less reliable overall than colonoscopy. If the CT colonography result is abnormal, a colonoscopy is required to evaluate the colon completely.
Cologuard is a test that requires patients to collect their faeces, scrape them with a probe, place them in a preservative-filled container, and mail it to the lab. This test looks for unusual DNA or blood traces in the stool, which could indicate precancerous polyps or CRC. Patients usually repeat the exam every three years. A colonoscopy is required for further assessment if the Cologuard test is positive. Cologuard's accuracy, however, is still restricted; 13% of the time, the test suggests that the patient has cancer when they don't. Annual FIT testing or colonoscopy may be more effective and less expensive than Cologuard, according to a study published in 2019. More study is being conducted to determine how reliable (and so beneficial) this test is at detecting CRC.
Which type of screening should you go with?
The most crucial aspect of colon cancer screening is having a test performed. Colonoscopy or FIT testing are the most popular procedures to screen for colon cancer in most patients. If you can't or don't want to have a colonoscopy or FIT testing, there are other choices to think about. Finally, this is a personal and essential decision that a patient should address with their healthcare professional so that the appropriate test can be performed at the appropriate time.
For average-risk people, the United States Preventative Services Task Force recommends commencing CRC screening at the age of 45.
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