Serrated Polyps and Serrated Polyposis Syndrome

Not All Patients With Locally Advanced Rectal Cancer Benefit From Neoadjuvant Therapy

BACKGROUND

While neoadjuvant combined modality therapy (NA-CMT) is beneficial for most patients with locally advanced rectal cancer some patients may experience disease progression during treatment. The purpose of this study is to identify characteristics associated with progression during NA-CMT.

METHODS

A single institution retrospective review of patients with stage II-III rectal cancer receiving NA-CMT was conducted from 2008-2019. Patients with incomplete or unknown NA-CMT treatment and those who received chemotherapy in addition to NA-CMT were excluded. Initial staging MRI was compared to post-operative pathology to determine progression. Definitions: responders (complete response or regression) and non-responders (stable disease or progression).

RESULTS

156 patients were included: 25 (16.1%) complete responders, 79 (50.6%) had evidence of regression, 34 (21.8%) were stable non-responders, and 18 (11.5%) were progressors. Those who progressed had worse overall survival. Factors associated with non-responders included black race (OR 4.5, 95% CI: 1.10-18.7) and increasing distance from the anal verge (OR 1.2, 95% CI: .2-2.9). Distance from the anal verge was determined via MRI. Recurrence was significantly more common among non-responders (15, 30.61%) when compared to responders (14, 13.46%), P = .012.

CONCLUSION

Patients who progress despite NA-CMT have overall worse survival compared to patients who do respond. While this study failed to identify modifiable or predictive risk factors for progression, the multivariate logistic regression model suggests that race and tumor biology may play a role in progression. Future studies should focus on early identification of patients who may not benefit from NA-CMT in an effort to develop alternative treatment algorithms.

Nanomedicines in the treatment of colon cancer: a focus on metallodrugs

Worldwide, colon cancer (CC) represents the fourth most common type of cancer and the fifth major cause of cancer-associated deaths. Surgical resection is considered the standard therapeutic choice for CC in early stages. However, in latter stages of the disease, adjuvant chemotherapy is essential for an appropriate management of this pathology. Metal-based complexes displaying cytotoxic properties towards tumor cells emerge as potential chemotherapeutic options. One metallodrug, oxaliplatin, was already approved for clinical use, playing an important role in the treatment of CC patients. Unfortunately, most of the newly designed metal-based complexes exhibit lack of selectivity against cancer cells, low solubility and permeability, high dose-limiting toxicity, and emergence of resistances. Nanodelivery systems enable the incorporation of metallodrugs at adequate payloads, solving the above-referred drawbacks. Moreover, drug delivery systems, depending on their physicochemical properties, are able to release the incorporated material preferentially at affected tissues/organs, enhancing the therapeutic activity in vivo, with concomitant fewer side effects. In this review, the general features and therapeutic management of CC will be addressed, with a special focus on preclinical or clinical studies using metal-based compounds. Furthermore, the use of different nanodelivery systems will also be described as tools to potentiate the therapeutic index of metallodrugs for the management of CC.

Comprehensive Analysis of Serum Metabolites Profiles in Acute Radiation Enteritis Rats by Untargeted Metabolomics

Acute radiation enteritis is a common complication occurring in patients with pelvic and abdominal tumors who receive radiotherapy. Acute radiation enteritis seriously reduces the life quality, even threatens the lives of patients. Untargeted metabolomics is an emerging strategy to explore the novel biomarkers and uncover potential pathogenesis of acute radiation enteritis. Acute radiation enteritis rat model was established by single abdominal irradiation with a gamma-ray dose of 10 Gy. Serum from 15 acute radiation enteritis rats and 10 controls was extracted for metabolomics analysis by UHPLC-Q-TOF/MS. Clinical manifestations and morphological alterations of intestine confirmed the successful establishment of acute radiation enteritis. According to the metabolomics data, 6,044 positive peaks and 4,241 negative peaks were extracted from each specimen. OPLS-DA analysis and the heat map for cluster analysis showed satisfactory discriminatory power between acute radiation enteritis rats and controls. Subsequent analysis extracted 66 significantly differentially expressed metabolites, which might be potential biomarkers for acute radiation enteritis diagnosis. Moreover, Kyoto Encyclopedia of Genes and Genomes enrichment analyses uncovered the potential mechanisms through which differentially expressed metabolites participated in acute radiation enteritis pathogenesis. To sum up, we summarized several differentially expressed serum metabolites as potential biomarkers for diagnosis of acute radiation enteritis and provide latent clues for elucidating acute radiation enteritis pathology.

Do Water-aided Techniques Improve Serrated Polyp Detection Rate During Colonoscopy?: A Systematic Review With Meta-Analysis

BACKGROUND AND STUDY AIMS

The utility of water-aided techniques (WT): water exchange (WE) and water immersion (WI) have been studied extensively in the literature for improving colonoscopy outcome metrics such as adenoma detection rate. Serrated polyps owing to their location and appearance have a high miss rate. The authors performed a systematic review and meta-analysis of studies comparing WT with the standard gas-assisted (GA) method to determine if there was any impact on serrated polyp detection rate (SPDR) and sessile serrated polyp detection rate.

METHODS

The following databases were queried for this systematic review: Medline, EMBASE, Cochrane Library, CINAHL, and Web of Sciences. The authors only included randomized controlled trials (RCTs). The primary outcome was SPDR and secondary outcomes were sessile serrated polyp detection rate and cecal intubation rate. Risk ratios (RRs) were calculated for each outcome. A P-value <0.05 was considered to be statistically significant.

RESULTS

A total of 4 RCTs (5 arms) with 5306 patients (2571 in the GA group and 2735 in the WT group) were included. The SPDR was significantly increased for the WT group compared with GA (6.1% vs. 3.8%; RR, 1.63; 95% confidence interval, 1.24-2.13; P<0.001; I2=22.7%). A subgroup analysis for WE technique also demonstrated improved SPDR compared with the GA method (4.9% vs. 3.2%; RR, 1.57; 95% confidence interval, 1.15-2.14; P=0.004; I2=6.1%).

CONCLUSIONS

WT, particularly, the WE method results in improved SPDR. This technique should be encouraged in a clinical setting to detect these polyps to prevent interval colorectal cancer.

Comparing endoscopic interventions to improve serrated adenoma detection rates during colonoscopy: a systematic review and network meta-analysis of randomized controlled trials

OBJECTIVE

Serrated lesions (sessile serrated adenomas/polyps and traditional serrated adenomas) owing to their subtle appearance and proximal location have a high miss rate. The objective of this study is to compare all the available endoscopic interventions for improving serrated adenoma detection rate (SADR) through a network meta-analysis.

METHODS

We conducted a systematic review of the available literature (PubMed, Embase, Cochrane and WoS) from inception to 29 November 2019 to identify all the relevant randomized controlled trials. A total of 28 trials with 22 830 patients were included. The studies compared the efficacy of add-on devices (endocap, endocuff, endocuff vision, G-EYE, endorings, AmplifEYE), electronic chromoendoscopy (linked-color imaging, blue laser imaging, narrow band imaging), dye-based chromoendoscopy, full-spectrum endoscopy (FUSE) and water-based techniques (WBT) with each other or high-definition colonoscopy. Both pairwise and network meta-analysis was conducted using the random-effects model. Risk ratios (RR) with 95% confidence intervals (CI) and P-values were calculated.

RESULTS

Direct meta-analysis demonstrated superiority for WBT (RR: 1.41, CI: 1.01-1.98), add-on devices (RR: 1.53, CI: 1.13-2.08), narrow band imaging (RR: 1.93, CI: 1.12-3.32) and endocuff vision (RR: 1.87, CI: 1.13-3.11) compared to high-definition colonoscopy. The results were consistent on network meta-analysis with chromoendoscopy as an additional modality for improving SADR (RR: 1.74, CI: 1.03-2.93).

CONCLUSION

In a network meta-analysis, add-on devices (particularly endocuff vision), narrow band imaging, WBT and chromoendoscopy were comparable to each other and improved SADR compared to high-definition colonoscopy.

Improving serrated adenoma detection rate in the colon by electronic chromoendoscopy and distal attachment: systematic review and meta-analysis

BACKGROUND AND AIMS

The evidence for modification of conventional colonoscopy using either "distal attachments" (DAs; endocap, endocuff, and endoring) or "electronic chromoendoscopy" (EC; narrow-band imaging [NBI], iScan, blue-light imaging, autofluorescence imaging, and linked-color imaging) to improve the detection of serrated adenomas during colonoscopy has shown conflicting results.

METHODS

A comprehensive literature search was performed using Medline, Google Scholar, Embase, and Cochrane Library based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials (RCTs) comparing any DA or EC with high-definition white-light colonoscopy for detection of serrated adenomas (sessile serrated adenoma/polyp and traditional serrated adenoma) were included. The primary outcome was serrated adenoma detection rate (SADR) defined as the number of patients with at least 1 serrated adenoma of total patients in that group. The secondary outcome was the number of serrated adenomas per subject. Pooled rates were reported using risk ratio (RR) with 95% confidence interval.

RESULTS

Seventeen studies with 13,631 patients (56% men; age range, 50-66 years) met the inclusion criteria. The use of DAs (RR, 1.21; P = .45) and EC (RR, 1.29; P = .09) during colonoscopy did not show a significant improvement in SADR. The SADR using EC was 6.9% (4 studies) and that with NBI alone was 3.7% (3 studies).

CONCLUSIONS

The results indicate that, except for NBI, the use of DAs or EC during colonoscopy does not improve detection of serrated adenomas in the colon. More RCTs evaluating NBI are needed to explore the effect.