Linked color imaging, a novel endoscopy technique, was significantly more effective than white-light imaging in identifying neoplastic lesions in the upper gastrointestinal tract, based on data from a randomized trial of 1,502 adults with previous or current gastrointestinal cancers.
Linked color imaging (LCI) allows users to detect neoplastic lesions by recognizing subtle differences in mucosal color, wrote Shoko Ono, MD, of Hokkaido University Hospital, Sapporo, Japan, and colleagues.
“Since the recent launch of image-enhanced endoscopy, many studies have evaluated its efficacy in diagnosing upper GI neoplasms as well,” the researchers wrote. However, “most have focused on the evaluation of histologic diagnosis, whereas few have focused on neoplasm detection.”
In a study published in Annals of Internal Medicine, the researchers randomized 750 patients to the LCI group and 752 to a white light–imaging (WLI) group. LCI patients underwent LCI followed by WLI; WLI patients underwent WLI followed by LCI. The primary outcome was a diagnosis of one or more neoplastic lesions in the pharynx, esophagus, or stomach during the first examination.
LCI identifies more lesions on first exam
Overall, 60 patients in the LCI group met the primary outcome, compared with 36 patients in the WLI group (8.0% vs. 4.8%, P = .011).
As a secondary endpoint, the researchers assessed the percentage of patients with one or more neoplastic lesions identified in the second examination, but not in the first. The number of overlooked lesions was significantly lower in the LCI group, compared with the WLI group (5 patients, 0.67% vs. 26 patients, 3.5%).
The patients were aged 20-89 years and had previous or current cancer of the pharynx, esophagus, stomach, or large intestine, and were therefore considered at high risk for upper GI tract tumors.
The study findings were limited by the lack of blinding of the endoscopists and the inclusion only of high-risk patients, meaning that the results might not be generalizable to general clinicians and an average-risk population, the researchers noted. “However, LCI images resemble those obtained by conventional WLI. Thus, LCI can be expected to provide efficacy similar to that of conventional white light endoscopy even if general clinicians were to use LCI for cancer screening in an average population.”
White light misses lesions
“Our manuscript provides very important messages regarding endoscopic modality for upper GI cancer screening,” corresponding author Mototsugo Kato, MD, of National Hospital Organization Hakodate (Japan) National Hospital, said in an interview. LCI can reduce the number of missed neoplastic lesions when screening patients for upper GI cancer.
In the current study, “white-light imaging missed about 40% of neoplastic lesions. On the other hand, LCI observation missed only 7% of neoplastic lesions. LCI emphasizes the difference in color to make it easier to detect neoplastic lesions,” he emphasized.
“This randomized clinical study demonstrated that LCI can detect neoplastic lesions in the upper GI tract (pharynx, esophagus, and stomach) 1.67 times more frequently than WLI,” said Dr. Kato. “This result indicates that many neoplastic lesions are being overlooked by conventional white light endoscopy performed in routine clinical practice.” There are no particular disadvantages to using LCI over WLI.
As for additional research, “The experts in upper GI endoscopy performed the examinations on populations at high risk for neoplasms in the pharynx, esophagus, or stomach,” Dr. Kato said. “It is unclear whether these examinations, if performed by general clinicians on an average population, would yield results similar to those obtained by the highly experienced endoscopists in this study.”
Randomized data are promising, more studies needed
“LCI and other virtual chromoendoscopy technologies have been shown to enhance detection of neoplastic lesions in a number of smaller studies,” said Ziad F. Gellad, MD, of Duke University Medical Center, Durham, N.C., in an interview.
The current study is important because it represents a well-designed randomized, controlled trial to better understand the efficacy of LCI as compared with standard imaging techniques. “This level of scientific rigor is needed to advance the field,” he said.
Dr. Gellad said that the findings are consistent with preliminary data from LCI studies. “In the hands of expert endoscopists who are familiar with the technology, I am not surprised with the results,” which are consistent with other studies of advanced imaging techniques.
“There are two main barriers to use of LCI in clinical practice. The biggest barrier to use of LCI in clinical practice is whether the efficacy seen in expert hands translates when used by a broader group of endoscopists. Obviously, the use of this technology would also require endoscopists to use the Fujinon equipment used in the study. Another barrier is whether the findings will hold in a population that has not been selected for high risk of neoplastic lesions as was the group in this study,” he added.
“Additional research is needed to see whether the efficacy of LCI holds up in the hands of nonexpert endoscopists,” Dr. Gellad emphasized. “Furthermore, clarifying the indications where this technology is appropriate will also be critically important to broader use.”
“Missed neoplasia and dysplasia during cancer surveillance programs among patients with Barrett’s esophagus and gastric intestinal metaplasia remains a concern,” said Avinash Ketwaroo, MD, of Baylor College of Medicine, Houston, in an interview. “Endoscopists await further advances in endoscopic imaging characteristics such as spatial resolution and contrast enhancement that can help improve neoplasia detection.” Given the improvement with narrow-band imaging (NBI) over WLI, Dr. Ketwaroo said he was not surprised that other enhanced imaging modalities such as LCI would be superior to WLI.
However, potential barriers to the clinical adoption of LCI include equipment costs and training time, and the consideration of whether LCI is superior enough to NBI to justify the cost of equipment, Dr. Ketwaroo noted.
“Additionally, our patient population and indications for neoplasia/dysplasia surveillance are different than those described in the study,” he said. Therefore, additional research is needed to compare LCI with NBI, “especially in the context of surveillance programs common in the West (esophageal cancer/Barrett’s esophagus).” .
The study was sponsored by Fujifilm. Lead author Dr. Ono had no financial conflicts to disclose. Dr. Kato disclosed speaking and teaching commitments for Takeda Pharmaceutical and Otsuka Pharmaceutical, and has received scholarship grants from Fujifilm. Dr. Gellad and Dr. Ketwaroo had no disclosures but both serve on the editorial advisory board of GI & Hepatology News.
SOURCE: Ono S et al. Ann Intern Med. 2020 Oct 19. doi: 10.7326/M19-2561.