New technologies could revolutionize colonoscopy effectiveness
Key Takeaways
Younger people are facing an increased burden of colorectal cancer, with screening in younger populations becoming increasingly important.
New endoscopy technologies such as linked color imaging can help enhance colors on photos and boost identification of colorectal cancer lesions.
MRI colonography is a non-invasive modality that detects colorectal polyps and colorectal cancer, as well as assessing cancer metastases, while orally ingested CT capsules take images as they transit the bowel.
Experts note disturbing trends in the incidence of early-onset colorectal cancer (EOCRC). Results from a recent study showed a distinct association between younger age and an increased risk for distant-stage disease, with this trend most noted in non-Hispanic Black and Hispanic groups.[]
Distant-stage disease plays a big role in the overall burden of rectal and colon cancer. The biggest impact is in patients in their 20s and 30s, according to the data. Younger age at presentation is linked to a higher risk of metastatic disease at presentation.
These are important trends to be aware of, despite the low absolute rates of colorectal cancer in younger individuals.
Fortunately, clinicians can screen for EOCRC, and the authors of the study recommend dropping the average-risk screening age from 50 to 45 years, as well as encouraging clinicians to heed potentially worrisome symptoms in younger patients and consider family history.
On the bright side, colonoscopy technology is advancing by leaps and bounds. Here are some newer techniques to consider.
Endoscopy 2.0
Techniques that enhance endoscopic images can help ensure that subtle lesions are not missed.
Linked color imaging (LCI) renders red areas on endoscopy still images redder and white areas whiter, improving the accuracy of identifying gastrointestinal and colorectal cancer lesions. In other words, these colors “pop,” which could help clinicians with less experience in identifying lesions.
Results from a recent randomized, controlled trial published in Endoscopy International Open concluded that LCI is better than other image-enhanced endoscopy technologies such as blue laser imaging (BLI) and BLI-bright in identifying sessile serrated adenoma/polyps (SSA/Ps).[] Moreover, LCI beats out conventional white-light images (WLIs). Detection rates by both expert and non-expert endoscopists were compared.
Evaluation of average color differences between the lesions and the background mucosa, which were highest in LCI mode, provided objective substantiation for these results.
“These results strongly suggest that endoscopic observation utilizing LCI mode improves the detection and diagnosis of SSA/Ps that may sometimes be overlooked with conventional WLI observation,” the authors wrote.
"While both groups of endoscopists received significant benefit from LCI, the benefit was even greater for non-expert endoscopists."
— Fujimoto et al.
MRI colonography
This novel, non-invasive modality picks up colorectal polyps and colorectal cancer, and it can also assess for cancer metastases. Its advantage over computed tomography (CT) colonography is that it does not use any ionizing radiation. It does, however, require bowel preparation similar to that done for colonoscopy.
As with general MRI, contraindications include the presence of metal implants or severe patient claustrophobia. Potential adverse events include water spillage or incontinence. Constipation might also result from the use of high-concentrate barium.
During MRI colonography, the colon is distended with water, air, or carbon dioxide. The patient also needs to change positions, as with colonoscopy.
According to data cited in an article published in Nature Reviews, the colorectal cancer detection rate was 98.2%; the pooled sensitivity for detection of large polyps was 82%, and for any polyp, it was 38%.[] Although promising, this modality needs further research via high-powered studies.
CT capsule
This x-ray technology takes the form of an imaging capsule called Check-Cap, which is swallowed As the capsule transits the colon, it emits low-dose x-ray beams by means of a mini motor.
No bowel prep is needed, although contrast is used to help identify the colon walls and differentiate polyps from stool. X-ray images are relayed from slices of the colon to a recording unit positioned at the patient’s back.
Preliminary results involving 46 volunteers are promising, with radiation exposure equal to about that of one chest x-ray.
This modality is currently being examined in multicenter studies.
What this means for you
With the burden of colorectal cancer shifting to younger populations, screening is a necessity. Physicians should be suspicious of questionable symptoms in a younger patient or someone with a strong family history, and thus maintain a low threshold for screening. The hope is that newer screening technologies will make the experience more bearable and boost the efficacy of polyp detection.