Rates of metachronous adenoma after curative resection for left-sided or right-sided colon cancer

Delineation of gastrointestinal tumors biopsies using a fluorescence lifetime imaging optical fiber probe

Autofluorescence spectroscopy has emerged in recent years as a powerful tool to report label-free contrast between normal and diseased tissues, both in vivo and ex-vivo. We report the application of an instrument employing an optical fiber probe and capable of performing real-time autofluorescence lifetime imaging at a macroscopic scale, under bright background conditions. We validate and demonstrate the practicality of this technology to discriminate healthy against neoplastic tissue in freshly excised tumor biopsies. The capability of delineating tumor margins through processing the fluorescence decays in the phasors domain was demonstrated on four different types of cancer, highlighting the broad range of potential clinical applications for the proposed approach. The presented results suggest that our autofluorescence lifetime imaging probe, together with phasor analysis, can offer a real-time tool to observe lifetime contrast on tissues and, thus, is a suitable candidate for improving in situ tissue diagnostics during surgery.

A survey of current practices in post-polypectomy surveillance in Korea

BACKGROUND/AIMS

We investigated the clinical practice patterns of post-polypectomy colonoscopic surveillance among Korean endoscopists.

METHODS

In a web-based survey conducted between September and November 2021, participants were asked about their preferred surveillance intervals and the patient age at which surveillance was discontinued. Adherence to the recent guidelines of the U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) was also analyzed.

RESULTS

In total, 196 endoscopists completed the survey. The most preferred first surveillance intervals were: a 5-year interval after the removal of 1-2 tubular adenomas < 10 mm; a 3-year interval after the removal of 3-10 tubular adenomas < 10 mm, adenomas ≥ 10 mm, tubulovillous or villous adenomas, ≤ 20 hyperplastic polyps < 10 mm, 1-4 sessile serrated lesions (SSLs) < 10 mm, hyperplastic polyps or SSLs ≥ 10 mm, and traditional serrated adenomas; and a 1-year interval after the removal of adenomas with highgrade dysplasia, >10 adenomas, 5-10 SSLs, and SSLs with dysplasia. In piecemeal resections of large polyps ( > 20 mm), surveillance colonoscopy was mostly preferred after 1 year for adenomas and 6 months for SSLs. The mean USMSTF guideline adherence rate was 30.7%. The largest proportion of respondents (40.8%-55.1%) discontinued the surveillance at the patient age of 80-84 years.

CONCLUSIONS

A significant discrepancy was observed between the preferred post-polypectomy surveillance intervals and recent international guidelines. Individualized measures are required to increase adherence to the guidelines.

The absolute number of small and diminutive adenomas with high-grade dysplasia is substantially higher compared with large adenomas: a retrospective pooled study

Introduction

The risk that a large polyp (≥10 mm) evolves into high-grade dysplasia (HGD) is relatively high compared with that of a small/diminutive polyp (<10 mm). Recently, the detection of small and diminutive polyps has been substantially improved with the advancement of endoscopy. However, further research is needed on the role of the incidence of HGD caused by the co-occurrence of small and diminutive polyps in the progression of HGD. In this study, we aim to investigate whether and how the small and diminutive polyps correlate with the incidence of HGD in the population.

Methods

The pooled data were deeply analyzed from four published randomized controlled trials (RCTs) regarding colon polyp detection. All polyps detected were examined and confirmed by pathologists. The primary outcome was the composition ratio of the HGD polyps in each polyp size category.

Results

Among a total of 3,179 patients with 2,730 polyps identified, there were 83 HGD polyps confirmed, and 68 patients had at least one polyp with HGD. The risk of development of HGD was lower for a single small and diminutive polyp than for one large polyp (2.18% vs. 22.22%, P < 0.0001). On the contrary, the composition ratio for HGD from small and diminutive polyps was significantly higher than that from the large ones (68.67% vs. 31.33%, P < 0.0001). The combined number of HGD presented a trend negatively correlated to size.

Conclusions

Our data demonstrated that the absolute number of HGD significantly derives more from small and diminutive polyps than from the large ones, and the collective number of small and diminutive polyps per patient is indicative of his/her HGD exposure. These findings positively provide novel perspectives on the management of polyps and may further optimize the prevention of colorectal cancer.

Systematic Review Registration

http://www.chictr.org.cn, identifier ChiCTR1900025235, ChiCTR1800017675, ChiCTR1800018058, and ChiCTR1900023086.

Risk factors of advanced metachronous neoplasms in surveillance after colon cancer resection

BACKGROUND/AIMS

Regular surveillance colonoscopy after colon cancer resection is recommended for detecting metachronous adenoma and cancer. However, risk factors for metachronous neoplasms have not been fully evaluated. We aimed to assess risk factors for advanced metachronous neoplasms during surveillance colonoscopy after colon cancer resection.

METHODS

Patients who underwent curative colectomy for nonmetastatic colon cancer between January 2002 and December 2012 were evaluated and followed up to December 2017.

RESULTS

A total of 293 patients were enrolled in this study. Among these, 179 (61.1%) were male, and the mean age was 63.2 ± 10.4 years. On perioperative clearing colonoscopy, synchronous high-risk adenomas (number ≥ 3, size ≥ 10 mm, high-grade dysplasia, villous histology, and serrated adenoma ≥ 10 mm) were detected in 95 patients (32.4%), and they were significantly associated with male sex, old age (≥ 65 years), current alcohol consumption, and current smoking (p < 0.05). During the follow-up period (mean 74.4 ± 36.4 months), advanced metachronous neoplasms were found in 45 patients (15.4%), including metachronous cancer in four (1.4%). In multivariate analysis, distal colon cancer (distal-to-splenic flexure; odds ratio [OR], 4.402; 95% confidence interval [CI], 1.658 to 11.689; p = 0.003), synchronous highrisk adenomas (OR, 3.225; 95% CI, 1.503 to 6.918; p = 0.003), and hypertension (OR, 2.270; 95% CI, 1.058 to 4.874; p = 0.035) were significant risk factors for advanced metachronous neoplasms.

CONCLUSION

During surveillance after curative colon cancer resection, patients with distal colon cancer, synchronous high-risk adenomas, and hypertension may need meticulous follow-up to improve overall outcomes.