Leading expert in colorectal cancer screening, Dr. Perry Pickhardt, MD, explains how CT colonography offers a superior preventive strategy. He details the optimal screening intervals for virtual colonoscopy. Dr. Perry Pickhardt, MD, discusses why stool-based tests are inadequate for detecting precancerous polyps. He advocates for a shift towards safer, more effective screening methods that focus on finding significant lesions while ignoring clinically irrelevant findings.
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Optimizing Colorectal Cancer Screening Intervals with CT Colonography
Jump To Section
- CT Colonography Screening Benefits
- Stool Test Limitations
- Screening Interval Recommendations
- Managing Small Polyps
- Age-Based Screening Guidance
- Full Transcript
CT Colonography Screening Benefits
Dr. Perry Pickhardt, MD, positions CT colonography as a premier preventive screening tool for colorectal cancer. He emphasizes that virtual colonoscopy provides an excellent balance of accuracy and safety. This method effectively detects advanced adenomas and large polyps that pose a cancer risk.
Dr. Perry Pickhardt, MD, notes that CT colonography offers significant advantages over traditional methods. It is a faster, safer, and more cost-effective screening option. The procedure delivers the same crucial prevention benefit as optical colonoscopy without the need for invasive polypectomy for insignificant findings.
Stool Test Limitations
Dr. Perry Pickhardt, MD, clearly states that fecal-based tests are inadequate for comprehensive colorectal cancer screening. Both fecal occult blood testing and stool DNA testing fail to reliably detect advanced adenomas. These tests cannot identify large precancerous polyps before they develop into cancer.
During his discussion with Dr. Anton Titov, MD, Dr. Perry Pickhardt, MD, explains why preventive tests that visualize the colon are essential. Only direct visualization methods like CT colonography and optical colonoscopy can find and characterize polyps effectively. This capability is crucial for true cancer prevention rather than just early cancer detection.
Screening Interval Recommendations
Dr. Perry Pickhardt, MD, provides specific guidance on screening intervals for CT colonography. He explains that virtual colonoscopy initially recommended a 5-year screening interval due to limited data. As evidence has accumulated, experts now recognize that longer intervals may be appropriate.
Dr. Pickhardt outlines the current protocol for negative CT colonography results. The first follow-up after a negative scan is typically at 5 years. Subsequent negative results can extend the interval to 10 years. This approach mirrors the established guidelines for optical colonoscopy while accounting for CT colonography's specific characteristics.
Managing Small Polyps
Dr. Perry Pickhardt, MD, highlights a key advantage of CT colonography in managing small polyps. Virtual colonoscopy intentionally leaves behind tiny diminutive polyps that don't require removal. This approach reduces unnecessary procedures and potential complications.
Dr. Pickhardt contrasts this with optical colonoscopy, where the discovery of even minute polyps often shortens the recommended screening interval. Many patients don't receive the full 10-year interval between colonoscopies because physicians frequently find insignificant polyps. CT colonography focuses screening efforts on clinically significant lesions that actually warrant attention.
Age-Based Screening Guidance
Dr. Perry Pickhardt, MD, discusses when to initiate and discontinue colorectal cancer screening. He emphasizes the importance of starting screening at the appropriate age to maximize preventive benefits. The specific starting age depends on individual risk factors and family history.
Dr. Pickhardt provides clear guidance on when to consider stopping routine screening. He recommends individualized decision-making for patients between ages 80 and 85. At this stage, many people can discontinue routine colorectal cancer screening based on their overall health status and previous screening history. This personalized approach ensures appropriate care throughout the lifespan.
Full Transcript
Dr. Anton Titov, MD: What is the time interval between two consecutive colon cancer screenings? Is it best to alternate virtual colonoscopy with flexible sigmoidoscopy for colorectal cancer screening? What should be done if a small polyp is found during colonoscopy? A leading virtual colonoscopy screening expert discusses CT colonography.
Dr. Anton Titov, MD: Screening for colon cancer. What is your current recommendation for the best method and frequency of screening for colorectal cancer? There are fecal occult blood tests, colonoscopy, and CT colonography.
Dr. Perry Pickhardt, MD: We look at colon cancer screening purely from a health risk perspective. We do not consider government funding or the cost perspective.
Dr. Anton Titov, MD: What is the age when someone should consider doing the first colonoscopy? What affects the frequency of screening for colon cancer?
Dr. Perry Pickhardt, MD: This is a very important topic, obviously. But if we are simply to consider patient outcomes and population health, it is clearly better to do a preventive test. The colon cancer screening test that can find polyps before they become colorectal cancer.
Fecal sample-based tests are not the answer. Fecal occult blood testing and stool DNA testing unfortunately simply do not do a good enough job to detect these advanced adenomas. Fecal occult blood testing does not find large polyps, whereas a preventive test does find large polyps.
We have optical colonoscopy and CT colonography. CT colonography is the preferred test because it has a nice balance between accuracy for detecting the important lesions. But virtual colonoscopy leaves behind the tiny diminutive colon polyps that really need not be removed.
Virtual colonoscopy can screen for the important precancerous colon lesions in a safer and cheaper way. It is a more effective method than optical colonoscopy. CT colonography is a better, faster, safer, cheaper colon cancer screening method.
CT colonography does so with the prevention benefit that both colonoscopy and CT colonography have. Sometimes optical colonoscopy is negative and can be done at 10-year intervals currently. However, it is very uncommon for many doctors not to find a tiny polyp during colonoscopy.
Patients receive a recommendation to repeat colonoscopy at sooner intervals. Many patients are disappointed that they often don't get the full 10-year interval between colonoscopies as is usually recommended.
For CT colonography, we started out at a 5-year interval for colon cancer screenings. We thought we didn't have enough data. We thought maybe virtual colonoscopy accuracy was closer to the barium enema.
We're finding that we could probably expand the interval between successive tests. Five to 10 years is probably the appropriate interval between two CT colonography tests. But virtual colonoscopy is still such a relatively new colon cancer screening test.
We are currently saying five years for the first follow-up. After that, you may continue to have a negative result. Then it is 10 years thereafter.
Once you reach the age of 80 to 85, then it becomes individualized whether or not you really need to continue screening. At that point, many people can probably discontinue routine screening for colon cancer.