Colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States, and rates are rising, particularly in adults ages 20 to 49. Unfortunately, approximately 30% of eligible people in the US still have not been screened for CRC.
Colon cancer may be prevented with screening tests that look for cancer or precancerous growths called colon polyps.
When should you start screening?
The United States Preventative Services Task Force recommends starting screening for CRC at age 45 for average-risk patients. These guidelines reflect the most up-to-date research on when risk for colon cancer begins to increase.
Average-risk patients are those with no personal or family history of colon cancer or a genetic condition that increases the risk of developing CRC. For this reason, it is important for patients to share their family history, including all cancer diagnoses in blood relatives, with their primary care doctor, who can help decide the right time to begin colon cancer screening.
High-risk patients are advised to begin screening before age 45. A primary care physician can help determine when and how a patient who is concerned about their risk level should be screened for CRC. Patients who have a history of CRC or polyps; a first-degree family member with CRC or advanced polyps (those that would have gone on to become CRC if they had not been removed); a family history of certain genetic syndromes; or a history of inflammatory bowel disease (like Crohn’s disease or ulcerative colitis) are some examples of high-risk factors.
What are the options for CRC screening?
Colonoscopy: Colonoscopy is the gold standard of screening tests, and identifies approximately 95% of CRC. It is also the only method that allows a gastroenterologist to both detect and remove potentially precancerous colon polyps. Colonoscopies are considered low-risk procedures, but they do have a small risk of bleeding and perforation that increases in older age groups.
Patients need to clean out their colon prior to the procedure by drinking a colonoscopy prep, which washes stool out of the colon so that it can be properly assessed during the procedure. The prescription instructions for the prep are provided by the gastroenterologist’s office.
In most cases, the procedure will be performed under sedation to ensure the patient is as comfortable as possible. It is important to note that patients are not placed under general anesthesia, but most remain sleepy and comfortable throughout their colonoscopy.
During the colonoscopy, a gastroenterologist will insert a flexible tube with a camera at the end, called a colonoscope, into the rectum. The entire colon is then carefully examined. If no polyps are detected and the preparation (cleanout) of the colon is adequate a repeat of a colonoscopy is suggested in 10 years. If polyps are detected, or the patient’s risk level or symptoms change, this interval will be shorter.
FIT testing: The fecal immunochemical test (FIT) is a lab test that looks for hidden blood in the stool. Patients use a kit to collect their stool and then use a probe to scrape the stool, which is then placed into a tube and mailed to the lab. FIT testing is repeated every year. A drawback of FIT testing is that it has a false positive rate of approximately 5%. It can effectively rule out CRC with 79% accuracy. FIT testing is noninvasive, convenient, and cost-effective, making it an acceptable alternative to a colonoscopy for many people. If a stool test is positive, a colonoscopy is needed to evaluate the reason for the positive test.
Flexible sigmoidoscopy: A flexible tube with a camera is used to look at the rectum and the lower part of the colon. The advantages of this procedure are that it is faster than a colonoscopy (only 5 to 15 minutes) and requires less aggressive laxative medications. Typically, patients receive a flexible sigmoidoscopy every five years if no polyps are detected. As this test does not examine the whole colon, it cannot detect cancers or polyps in the unexamined portion. At best, it can detect 70% of cancers and polyps.If an abnormality is detected, a follow-up colonoscopy is needed to look at the entire colon.
CT colonography: A CT scan is used to visualize your rectum and entire colon. Just like with a colonoscopy, patients need to take laxative medications the night before to empty the colon. A small tube is placed in the rectum to expand the colon to get clear pictures. This test may be useful for patients who cannot tolerate anesthesia or have other medical conditions that prevent them from having a colonoscopy. A drawback of CT colonography is radiation exposure and finding unrelated abnormalities outside the colon that can lead to unnecessary tests. While CT colonography is about 88.7% accurate at finding certain polyps, it is less accurate than colonoscopy overall. If the CT colonography result is abnormal, a colonoscopy is required for a full evaluation of the colon.
Cologuard: This is a test where patients collect their stool, scrape it with a probe, insert it into a container with preservative, and mail it to the lab. This test looks for atypical DNA, or traces of blood in the collected stool that may be suggestive of precancerous polyps or CRC. Typically, patients repeat the test every three years. If the Cologuard test is positive, a colonoscopy is necessary for further evaluation. However, Cologuard’s accuracy is still limited; 13% of the time the test indicates the patient may have cancer when they do not. In 2019, a study showed that annual FIT testing or colonoscopy may be more effective and less costly than Cologuard. Further research is ongoing to evaluate how accurate (and thus how useful) this test is at detecting CRC.
Which screening option should you choose?
The most important part of colon cancer screening is to have a screening test performed. For most patients, colonoscopy or FIT testing are the most common ways to screen for colon cancer. However, there are other options to consider if you are unable to undergo or are uncomfortable with colonoscopy or FIT testing. Ultimately, this is an important and personalized decision, and a discussion for a patient to have with their healthcare provider so that the right test can be done at the right time.
Bible verses for today’s meditation and inspiration: Matthew E. McLaren
Suppose you find fifty righteous people living there in the city—will you still sweep it away and not spare it for their sakes? (Genesis 18:24) And the Lord replied, “If I find fifty righteous people in Sodom, I will spare the entire city for their sake.” (Genesis 18:26)
And be sure to say, ‘Look, your servant Jacob is right behind us.’” Jacob thought, “I will try to appease him by sending gifts ahead of me. When I see him in person, perhaps he will be friendly to me.” (Genesis 32:20)
to say to you: ‘Please forgive your brothers for the great wrong they did to you—for their sin in treating you so cruelly.’ So we, the servants of the God of your father, beg you to forgive our sin.” When Joseph received the message, he broke down and wept. (Genesis 50:17)
“Forgive my sin, just this once, and plead with the Lord your God to take away this death from me.” (Exodus 10:17)
Pay close attention to him, and obey his instructions. Do not rebel against him, for he is my representative, and he will not forgive your rebellion. (Exodus 23:21)
Moses Intercedes for Israel The next day Moses said to the people, “You have committed a terrible sin, but I will go back up to the Lord on the mountain. Perhaps I will be able to obtain forgiveness for your sin.” (Exodus 32:30) So Moses returned to the Lord and said, “Oh, what a terrible sin these people have committed. They have made gods of gold for themselves. (Exodus 32:31) But now, if you will only forgive their sin—but if not, erase my name from the record you have written!” (Exodus 32:32)
The Lord passed in front of Moses, calling out, “Yahweh! The Lord! The God of compassion and mercy! I am slow to anger and filled with unfailing love and faithfulness. (Exodus 34:6) I lavish unfailing love to a thousand generations. I forgive iniquity, rebellion, and sin. But I do not excuse the guilty. I lay the sins of the parents upon their children and grandchildren; the entire family is affected— even children in the third and fourth generations.” (Exodus 34:7)
And he said, “O Lord, if it is true that I have found favor with you, then please travel with us. Yes, this is a stubborn and rebellious people, but please forgive our iniquity and our sins. Claim us as your own special possession.” (Exodus 34:9)
just as he does with the bull offered as a sin offering for the high priest. Through this process, the priest will purify the people, making them right with the Lord, and they will be forgiven. (Leviticus 4:20) Then he must burn all the goat’s fat on the altar, just as he does with the peace offering. Through this process, the priest will purify the leader from his sin, making him right with the Lord, and he will be forgiven. (Leviticus 4:26)
Then he must remove all the goat’s fat, just as he does with the fat of the peace offering. He will burn the fat on the altar, and it will be a pleasing aroma to the Lord. Through this process, the priest will purify the people, making them right with the Lord, and they will be forgiven. (Leviticus 4:31) Then he must remove all the sheep’s fat, just as he does with the fat of a sheep presented as a peace offering. He will burn the fat on the altar on top of the special gifts presented to the Lord. Through this process, the priest will purify the people from their sin, making them right with the Lord, and they will be forgiven. (Leviticus 4:35)
The priest will then prepare the second bird as a burnt offering, following all the procedures that have been prescribed. Through this process the priest will purify you from your sin, making you right with the Lord, and you will be forgiven. (Leviticus 5:10) Through this process, the priest will purify those who are guilty of any of these sins, making them right with the Lord, and they will be forgiven. The rest of the flour will belong to the priest, just as with the grain offering.” (Leviticus 5:13)
Recommended contacts for prayer requests and Bible study