Colonoscopy vs. CT Colonography: Differences and Advantages

Why Is Colon Cancer Screening Important?

Early action is crucial for colon cancer treatment. The longer cancer is left unaddressed, the further it spreads through the body. It invades new tissues and, eventually, new organs, finding a foothold in distant parts of the body. Once cancer spreads, it becomes extremely difficult to treat. Late stages of colon cancer require the most aggressive treatments with challenging side effects. They also have the poorest patient prognosis.

Routine screening makes early action possible. Screening tests can detect cancer long before any warning signs and symptoms develop, allowing care to begin while the cancer is in its earliest stage. This head start gives patients the best chance at a successful treatment and full rehabilitation.

What Is a Colonoscopy?

A colonoscopy is an invasive test that uses a specialized camera, called a colonoscope, to examine the colon lining from the inside. Individuals undergo a multiday bowel cleanse beforehand to ensure that their colon is free from obstructions. On test day, sedation or anesthesia may be used to keep the patient relaxed or asleep. The test itself follows these steps:

1. The physician inserts a colonoscope, a tiny camera mounted on a flexible tube, into the patient’s anus.
2. The physician blows carbon dioxide into the anus, inflating the colon to provide unrestricted access.
3. The physician guides the colonoscope up and down the whole length of the colon.
4. The physician uses the live video feed to examine the colon lining for abnormalities.
5. If any abnormalities are found, the physician may remove some tissue for a biopsy.

Bloating, gas, and cramping are other common side effects of a colonoscopy. This discomfort should fade as the carbon dioxide passes from the colon.

Benefits and Downsides of a Colonoscopy

A colonoscopy is considered the gold standard of colon cancer screening. Like any other diagnostic method, however, it has its strengths and weaknesses. These include:

Advantages of a Colonoscopy

The primary advantage of a colonoscopy is its effectiveness in detecting colon cancer. Because the video feed provides a direct view of the colon lining, it allows a very thorough search for cancer indicators. In addition, many colonoscopes are equipped with a cutting tool. If any polyps, tumor-like masses, or other suspicious growths are found, the doctor can perform a biopsy at the same time as the screening.

Because a colonoscopy is so effective, individuals can be screened less often. So long as tests remain clear, people only need a colonoscopy every 10 years after the age of 45. Individuals make fewer appointments and can spend more time focused on work, family time, and hobbies.

Disadvantages of a Colonoscopy

While colonoscopies are highly effective, they are also uncomfortable. The bowel cleanse requires following a clear liquid diet while taking strong laxatives. This translates into multiple days of severe diarrhea before the test can begin. The test itself is also uncomfortable, and the need for a sedative or anesthesia is a turn-off for many patients.

What Is CT Colonography?

Computed tomography (CT) technology is used for CT colonography, a non-invasive screening method that uses X-ray imaging to look for cancer. Individuals need to perform a bowel cleanse before testing, though it may not be as intensive as the cleanse before a colonoscopy. The test itself does not require anesthesia or a sedative. It follows these steps:

1. The person lies down on a narrow table.
2. The physician inserts a small tube that blows carbon dioxide into the anus, inflating the colon.
3. The technologist goes into a control room to operate the CT scanner.
4. The narrow table moves through a ring-shaped scanner that rotates around the patient.
5. The patient may be asked to lie in different positions at various points.

As with a colonoscopy, there may be some bloating or cramping after the test. These feelings will go away over the next day. Otherwise, there are no lasting side effects, and individuals can promptly return to work and other activities.

Benefits and Downsides of CT Colonography

Like a colonoscopy, CT colonography has a range of advantages and disadvantages that people must weigh when deciding which type of test to get. These include:

Advantages of a CT Colonography

To many people, the advantage of CT colonography is its non-invasive nature. The test requires a less aggressive bowel cleanse, and it does not require anesthesia or a sedative. Individuals can also avoid the discomfort caused by having a camera inserted into their anus. As a result, this screening type is considered preferable for many who are eligible.

Disadvantages of a CT Colonography

Though CT colonography is less uncomfortable, it is also less effective. The X-ray images provide a less complete image of the colon, meaning that warning signs are easier to miss. As a result, those who opt for CT colonography must be screened every three to five years. The test may not be recommended at all for individuals who are at higher-than-average risk of colon cancer.

The inability to biopsy is another downside of CT colonography. If any suspicious tissue is found, the fully external imaging test cannot remove it for a biopsy. The individual may need to schedule a colonoscopy anyway. Even if the suspicious tissue is not cancerous, physicians may require that colonoscopies be used for future screenings, just to be safe.

Which Type of Colon Cancer Screening Is Best?

So which test type is best? Ultimately, neither colonoscopy nor CT colonography is universally superior. Instead, the best choice for colon cancer screening depends on the individual’s health needs and preferences. Colonoscopy is the favored option for people who:

• Are at high risk of colon cancer
• Had suspicious results on a previous test
• Want fewer screening appointments
• Want peace of mind about colon cancer

Meanwhile, CT colonography may be preferable to individuals who:

• Are at average risk of colon cancer
• Have not had any abnormal colon screenings
• Want less discomfort from screening tests
• Do not like, or cannot have, anesthesia

Individuals who are approaching the recommended age for colon cancer screening should speak with their primary care provider about the types of screening tests available. A focused discussion can weigh all relevant factors to determine which approach is best for the individual.

Find Comprehensive Colon Cancer Care Near You in NJ, CT, MA, and the Washington, D.C., Area

Both colonoscopy and CT colonography are invaluable tools for cancer care. By detecting cancer early, they give patients the best opportunity for an effective treatment. If patients have a positive screening, they can receive treatment at Regional Cancer Care Associates. RCCA specialists provide care to more than 30,000 new patients and 265,000 established patients each year. RCCA physicians offer patients innovative therapies, including immunotherapies and targeted therapy, cutting-edge diagnostics as well as access to approximately 300 clinical trials in community-based centers close to home.

Frequently Asked Questions About Colon Cancer Screening

When should colon cancer screening begin?

The American Cancer Society (ACS) recommends that people at average risk of colon cancer begin routine screenings at age 45. There is no recommendation for people at above-average risk. These individuals should speak with their physician about the best time to start screening.

What are the benefits of CT colonography?

CT colonography is a non-invasive method of colon cancer screening. For those at average risk of colon cancer, this test lets people receive screening with less discomfort.

What are the benefits of a colonoscopy?

The number one benefit of a colonoscopy is its effectiveness in detecting colon cancer. The video feed provides a direct view of the colon lining, allowing a very thorough search for cancer indicators.

Is CT colonography effective at detecting colon cancer?

CT colonography is highly effective at detecting abnormalities in the colon, though it cannot be used to examine them directly or conduct a biopsy to confirm the presence of cancer.

Who should receive CT colonography?

CT colonography is recommended for individuals who are at average risk of colon cancer and who do not have a history of polyps or other suspicious screenings. It is not recommended for people who are pregnant.