CLINICOPATHOLOGICAL CHARACTERISTICS AND RISK FACTORS OF YOUNG-ONSET GASTRIC CARCINOMA: A SYSTEMATIC REVIEW AND META-ANALYSIS.

BACKGROUND: The characteristics of gastric carcinoma in young individuals differ from older individuals. We conducted a systematic review and meta-analysis to explore the clinicopathological features and risk factors associated with young-onset (<50 years) gastric carcinoma. METHODS: We searched for studies published between January 1, 1990, and September 1, 2023, on patients with young-onset gastric carcinoma in PubMed, EMBASE, Web of Science, and MEDLINE to explore clinicopathological characteristics among this specific patient group. Extracted information included the proportion of patients with symptoms or family history of gastric cancer, tumor location, and histological features such as Lauren or WHO histological classification and degree of differentiation. Additional analyses were conducted on risk factors such as a positive family history, Helicobacter pylori (H. pylori) infection, or high-risk nutritional or behavioral factors. The estimates were derived using random or fixed-effect models and included subgroup analyses based on different sex and age groups. This study was registered in PROSPERO (CRD42023466131). RESULTS: We identified 5,696 records, 1,292 were included in the quality assessment stage. Finally, 84 studies from 18 countries or regions including 89,447 patients with young-onset gastric carcinoma were included. Young-onset gastric carcinoma has slight female predominance (53.7%, 95%CI: 51.6-55.7%), with most having symptoms (87.0%, 95%CI: 82.4-91.7%). Family history was reported in 12.1% (95%CI: 9.5-14.7%). H. pylori infection was detected in 60.0% of cases (95%CI: 47.1-72.8%). The majority of these carcinomas were in the non-cardia region (89.6%, 95%CI:82.4-96.8%), exhibiting Lauren diffuse-type histology (71.1%, 95%CI: 66.8-75.3%) and poor/undifferentiated features (81.9%, 95%CI: 79.7-84.2%). A positive family history of gastric cancer was the most important risk factor associated with the development of gastric carcinoma in young individuals (pooled odds ratios [OR] 4.0, 95% CI: 2.8-5.2), followed by H. pylori infection (OR 2.3; 95% CI: 1.4-3.2) and dietary and other lifestyle risk factors. CONCLUSION: Young-onset gastric carcinoma exhibits specific clinicopathological characteristics, with positive family history being the most important risk factor. The majority of patients were symptomatic at diagnosis. These findings could help to inform future strategies for the early detection of gastric carcinoma among young individuals.

Global burden of young-onset gastric cancer: a systematic trend analysis of the global burden of disease study 2019.

BACKGROUND: While gastric cancer is generally declining globally, the temporal trend of young-onset (< 40 years) gastric cancer remains uncertain. We performed this analysis to determine the temporal trends of young-onset gastric cancer compared to late-onset cancer (≥ 40 years). METHODS: We extracted cross-sectional data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. The burden of gastric cancer from 1990 to 2019 was assessed through indicators including incidence and mortality rates, which were classified at global, national, and regional levels, and according to socio-demographic indexes (SDI) and age or sex groups. Joinpoint regression analysis was used to identify specific years with significant changes. The correlation between AAPC with countries' average SDI was tested by Pearson's Test. RESULTS: The global incidence rate of young-onset gastric cancer decreased from 2.20 (per 100,000) in 1990 to 1.65 in 2019 (AAPC: - 0.95; 95% confidence interval [CI] - 1.25 to - 0.65; P < 0.001). Late-onset cancer incidence also decreased from 59.53 (per 100,000) in 1990 to 41.26 in 2019 (AAPC: - 1.23; 95% CI - 1.39 to - 1.06, P < 0.001). Despite an overall decreasing trend, the incidence rate of young-onset cancer demonstrated a significant increase from 2015 to 2019 (annual percentage change [APC]: 1.39; 95% CI 0.06 to 2.74; P = 0.041), whereas no upward trend was observed in late-onset cancer. Mortality rates of young- and late-onset cancer both exhibited a significant decline during this period (AAPC: - 1.82; 95% CI - 2.15 to - 1.56; P < 0.001 and AAPC: - 1.69, 95% CI - 1.79 to - 1.59; P < 0.001). The male-to-female rate ratio for incidence and mortality in both age groups have been increasing since 1990. While countries with high SDI have had a greater decline in the incidence of late-onset gastric cancer (slope of AAPC change: - 0.20, P = 0.004), it was not observed in young-onset cancer (slope of AAPC change: - 0.11, P = 0.13). CONCLUSIONS: The global incidence and mortality rates of both young- and late-onset gastric cancer have decreased since 1990. However, the incidence rate of young-onset cancer has demonstrated a small but significant upward trend since 2015. There was disparity in the decline in young-onset gastric cancer among male and high SDI countries. These findings could help to inform future strategies in preventing gastric cancer in younger individuals.

Prevalence of Gastric Precursor Lesions in Countries With Differential Gastric Cancer Burden: A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions. METHODS: We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010). RESULTS: Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time. CONCLUSIONS: Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.

The Role of Screening and Early Detection in Upper Gastrointestinal Cancers.

Upper gastrointestinal cancers are among the leading causes of cancer deaths worldwide with exceptionally poor prognosis, which is largely attributable to frequently delayed diagnosis. Although effective screening is critical for early detection, the highly variable incidence of upper gastrointestinal cancers presents challenges, rendering universal screening programs suboptimal in most populations globally. Optimal strategies in regions of modest incidence, such as the United States, require a targeted approach, focused on high-risk individuals based on demographic, familial, and clinicopathologic risk factors. Assessment of underlying precancerous lesions has key implications for risk stratification and informing clinical decisions to improve patient outcomes.

Prevalence of Enteric Infections in Patients on Immune Checkpoint Inhibitors and Impact on Management and Outcomes.

BACKGROUND: Stool pathogen testing is recommended as part of the initial evaluation for patients with new-onset diarrhea on immune checkpoint inhibitors (ICIs), yet its significance has not been well-studied. We aimed to determine the impact of multiplex gastrointestinal (GI) pathogen PCR testing on the clinical course and use of immunosuppressive therapy in patients who develop diarrhea on ICIs. METHODS: This retrospective cohort included individuals who underwent GI pathogen panel PCR for diarrhea on ICIs at Memorial Sloan Kettering between 7/2015 and 7/2021. The primary outcome was use of immunosuppressive therapy for suspected immunotherapy-related enterocolitis (irEC). Secondary outcomes included diarrhea severity and endoscopic and histologic disease patterns. RESULTS: Among 521 ICI-treated patients tested for GI pathogens, 61 (11.7%) had a positive PCR. Compared to patients without detectable infections, patients with infections had more frequent grades 3-4 diarrhea (37.7% vs. 19.6%, P < .01) and colitis (39.3% vs. 14.7%, P < .01). However, patients with infections did not have higher rates of persistent or recurrent diarrhea and were less likely to receive steroids (P < .01) and second-line immunosuppressive agents (P = .03). In 105 patients with lower endoscopy, similar trends were observed and no differences in endoscopic severity or histologic patterns were noted between groups. CONCLUSIONS: GI infections in ICI-treated patients presenting with diarrhea are linked to more severe but self-limited clinical presentations and may be optimally treated with observation and supportive care alone. Routine and timely stool pathogen testing may help avert unnecessary empiric immunosuppression for suspected irEC, which has been linked to blunted antitumor responses and numerous adverse effects.

Clinical and molecular characteristics of early-onset vs average-onset esophagogastric cancer.

BACKGROUND: The rate of esophagogastric cancer is rising among individuals under 50 years of age. It remains unknown whether early-onset esophagogastric cancer represents a unique entity. This study investigated the clinical and molecular characteristics of early-onset and average-onset esophagogastric cancer . METHODS: We reviewed the Memorial Sloan Kettering Cancer Center gastric, esophageal, and gastroesophageal junction cancer database. Associations between baseline characteristics and tumor and germline molecular alterations were compared between those with early-onset and average-onset esophagogastric cancer using Fisher exact tests and the Benjamini-Hochberg method for multiple-hypothesis correction. RESULTS: We included 1123 patients with early-onset esophagogastric cancer (n = 219; median age = 43 years [range = 18-49 years]) and average-onset esophagogastric cancer (n = 904; median age = 67 years [range = 50-94 years]) treated between 2005 and 2018. The early-onset group had more women (39% vs 28%, P = .002). Patients with early-onset esophagogastric cancer were more likely to have a gastric primary site (64% vs 44%, P < .0001). The signet ring cell and/or diffuse type was 3 times more common in the early-onset esophagogastric cancer group (31% vs 9%, P < .0001). Early-onsite tumors were more frequently genomically stable (31% vs 18%, P = .0002) and unlikely to be microsatellite instability high (2% vs 7%, P = .003). After restricting to adenocarcinoma and signet ring cell and/or diffuse type carcinomas, we observed no difference in stage (P = .40) or overall survival from stage IV diagnosis (median = 22.7 vs 22.1 months, P = .78). CONCLUSIONS: Our study supported a preponderance of gastric primary disease sites, signet ring histology, and genomically stable molecular subtypes in early-onset esophagogastric cancer. Our findings highlight the need for further research to define the underlying pathogenesis and strategies for early detection and prevention.

Impact of Helicobacter pylori infection status on outcomes among patients with advanced gastric cancer treated with immune checkpoint inhibitors.

BACKGROUND: Gut microbiota composition can influence cancer immunotherapy response. Recent evidence suggests Helicobacter pylori infection may reduce immune checkpoint inhibitor (ICI) efficacy in lung cancer and melanoma, but thorough characterization of this association in patients with gastric cancer is lacking. We aimed to determine the impact of H. pylori on survival in this population. METHODS: This single-center, retrospective study included all ICI-treated individuals with metastatic gastric cancer and documented H. pylori status at Memorial Sloan Kettering between July 2013 and October 2021. H. pylori-positive status was defined as history of infection obtained via breath test, stool antigen test, histopathology, and/or chart documentation. Negative status was defined as explicitly negative testing, histopathology, and/or chart documentation. Primary outcomes were progression-free survival (PFS) and overall survival (OS). RESULTS: Of 215 included patients, 49 had documented history of H. pylori infection. Compared with H. pylori-negative patients, positive individuals tended to be younger, non-white, and Hispanic with non-cardia and intestinal-type gastric cancer. H. pylori-positive patients had significantly shorter median PFS (3.2 vs 6.8 months, HR 1.96, p<0.01) and OS (9.8 vs 17.9 months, HR 1.54, p=0.02). Multivariable analysis confirmed H. pylori infection as an independent predictor of PFS (HR 3.04, p<0.01) and OS (HR 2.24, p=0.01). CONCLUSIONS: In this largest study of its kind, H. pylori infection was associated with inferior survival in ICI-treated patients with gastric cancer. This suggests H. pylori status may be a prognostic marker of immune responsiveness. Future studies are needed to elucidate immunoregulatory mechanisms and whether treatment of active infections would improve immunotherapy outcomes.

Factors associated with detection of hereditary diffuse gastric cancer on endoscopy in individuals with germline CDH1 mutations.

BACKGROUND AND AIMS: Individuals with germline pathogenic CDH1 variants have a high risk of hereditary diffuse gastric cancer. The sensitivity of EGD in detecting signet ring cell carcinoma (SRCC) in this population is low. We aimed to identify endoscopic findings and biopsy practices associated with detection of SRCC. METHODS: This retrospective cohort included individuals with a germline pathogenic/likely pathogenic CDH1 variant undergoing at least 1 EGD at Memorial Sloan Kettering Cancer Center between January 1, 2006, and March 25, 2022. The primary outcome was detection of SRCC on EGD. Findings on gastrectomy were also assessed. The study included periods before and after implementation of the Cambridge protocol for endoscopic surveillance, allowing for assessment of a spectrum of biopsy practices. RESULTS: Ninety-eight CDH1 patients underwent at least 1 EGD at our institution. SRCC was detected in 20 (20%) individuals on EGD overall and in 50 (86%) of the 58 patients undergoing gastrectomy. Most SRCC foci were detected in the gastric cardia/fundus (EGD, 50%; gastrectomy, 62%) and body/transition zone (EGD, 60%; gastrectomy, 62%). Biopsy results of gastric pale mucosal areas were associated with detection of SRCC (P < .01). The total number of biopsy samples taken on EGD was associated with increased detection of SRCC (P = .01), with 43% detected when ≥40 samples were taken. CONCLUSIONS: Targeted biopsy sampling of gastric pale mucosal areas and increasing number of biopsy samples taken on EGD were associated with detection of SRCC. SRCC foci were mostly detected in the proximal stomach, supporting updated endoscopic surveillance guidelines. Further studies are needed to refine endoscopic protocols to improve SRCC detection in this high-risk population.

Controlling Gastric Cancer in a World of Heterogeneous Risk.

Gastric cancer (GC) is a leading cause of global mortality but also a cancer whose footprint is highly unequal. This review aims to define global disease epidemiology, critically appraise strategies of prevention and disease attenuation, and assess how these strategies could be applied to improve outcomes from GC in a world of variable risk and disease burden. Strategies of primary prevention focus on improving the detection and eradication of the main environmental risk factor, Helicobacter pylori. In certain countries of high incidence, endoscopic or radiographic screening of the asymptomatic general population has been adopted as a means of secondary prevention. By contrast, identification and targeted surveillance of individuals with precancerous lesions (such as intestinal metaplasia) is being increasingly embraced in nations of low incidence. This review also highlights existing knowledge gaps in GC prevention as well as the role of emerging technologies for early detection and risk stratification.

A Novel Microbiome Signature in Gastric Cancer: A Two Independent Cohort Retrospective Analysis.

OBJECTIVE: The microbiome is hypothesized to have a significant impact on cancer development. In gastric cancer (GC), Helicobacter pylori is an established class I carcinogen. However, additional organisms in the intratumoral microbiome play an important role in GC pathogenesis and progression. In this study, we characterize the full spectrum of the microbes present within GC and identify distinctions among molecular subtypes. METHODS: A microbiome bioinformatics pipeline that is generalizable across multiple next-generation sequencing platforms was developed. Microbial profiles for alpha diversity and enrichment were generated for 2 large, demographically distinct cohorts: (1) internal Memorial Sloan Kettering Cancer Center (MSKCC) and (2) The Cancer Genome Atlas (TCGA) cohorts. A total of 520 GC samples were compared with select tumor-adjacent nonmalignant samples. Microbiome differences among the GC molecular subtypes were identified. RESULTS: Compared with nonmalignant samples, GC had significantly decreased microbial diversity in both MSKCC and TCGA cohorts ( P <0.05). Helicobacter , Lactobacillus , Streptococcus , Prevotella , and Bacteroides were significantly more enriched in GC samples when compared with nonmalignant tissue ( P <0.05). Microsatellite instability-high GC had distinct microbial enrichment compared with other GC molecular subtypes. CONCLUSION: Distinct patterns of microbial diversity and species enrichment were identified in patients with GC. Given the varied spectrum of disease progression and treatment response of GC, understanding unique microbial signatures will provide the landscape to explore key microbial targets for therapy.

Prospective Proteomic Study Identifies Potential Circulating Protein Biomarkers for Colorectal Cancer Risk.

BACKGROUND: Proteomics-based technologies are emerging tools used for cancer biomarker discovery. Limited prospective studies have been conducted to evaluate the role of circulating proteins in colorectal cancer (CRC) development. METHODS: A two-stage case-control proteomics study nested in the Shanghai Women's Health Study was conducted. A total of 1104 circulating proteins were measured in the discovery phase, consisting of 100 incident CRC cases and 100 individually matched controls. An additional 60 case-control pairs were selected for validation. Protein profiling at both stages was completed using the Olink platforms. Conditional logistic regression was used to evaluate the associations between circulating proteins and CRC risk. The elastic net method was employed to develop a protein score for CRC risk. RESULTS: In the discovery set, 27 proteins showed a nominally significant association with CRC risk, among which 22 were positively and 5 were inversely associated. Six of the 27 protein markers were significantly associated with CRC risk in the validation set. In the analysis of pooled discovery and validation sets, odds ratios (ORs) per standard deviation (SD) increase in levels of these proteins were 1.54 (95% confidence interval (CI): 1.15-2.06) for CD79B; 1.71 (95% CI: 1.24-2.34) for DDR1; 2.04 (95% CI: 1.39-3.01) for EFNA4; 1.54 (95% CI: 1.16-2.02) for FLRT2; 2.09 (95% CI: 1.47-2.98) for LTA4H and 1.88 (95% CI: 1.35-2.62) for NCR1. Sensitivity analyses showed consistent associations for all proteins with the exclusion of cases diagnosed within the first two years after the cohort enrollment, except for CD79B. Furthermore, a five-protein score was developed based on the six proteins identified and showed significant associations with CRC risk in both discovery and validation sets (Discovery: OR1-SD = 2.46, 95% CI: 1.53-3.95; validation: OR1-SD = 4.16, 95% CI: 1.92-8.99). CONCLUSIONS: A panel of five protein markers was identified as potential biomarkers for CRC risk. Our findings provide novel insights into the etiology of CRC and may facilitate the risk assessment of the malignancy.

Prevalence of Extensive and Limited Gastric Intestinal Metaplasia and Progression to Dysplasia and Gastric Cancer.

BACKGROUND AND AIMS: Guidelines cite extensive gastric intestinal metaplasia (GIM) as a bigger risk factor for gastric cancer (GC) than limited GIM and an indication for endoscopic surveillance. Data on progression of extensive GIM to GC in the USA are limited. This study aimed to estimate the prevalence and progression rates of extensive GIM in a US cohort. METHODS: This retrospective study assessed the prevalence of extensive GIM between 1/1/1990 and 8/1/2019 at a large academic medical center. Multivariable regression was used to identify predictors of extensive GIM. Incidence of GC on follow-up was calculated as number of new diagnoses divided by person-years of follow-up. Presence of GIM on subsequent follow-up endoscopy was assessed. RESULTS: Of 1256 individuals with GIM, 352 (28%) had extensive GIM and 904 (72%) had limited GIM. On multivariable analysis, older age (OR 1.01, 95% CI 1.00-1.02) and Hispanic ethnicity (OR 1.55, 95% CI 1.11-2.16) were predictive of extensive GIM. The annual incidence of GC for GIM overall was 0.09%. There was no difference in progression to GC between extensive or limited GIM (IRR 0, 95% CI 0-2.6), or to advanced lesions overall (IRR 0.37, 95% CI 0.04-1.62). 70% of individuals had persistent GIM on follow-up biopsy, and 22% with limited GIM had extensive GIM on follow-up biopsy. CONCLUSIONS: 28% of individuals with GIM have the extensive subtype, and are more likely to be older and of Hispanic ethnicity. There was no difference in progression to GC between extensive and limited GIM. Further research is needed to better assess risk of GIM in the US context.

Cost-effectiveness of prevention and early detection of gastric cancer in Western countries.

Gastric cancer (GC) is a significant global health problem, with Helicobacter pylori infection estimated to be responsible for 89% of non-cardiac GC cases, or 78% of all GC cases. The International Agency for Research on Cancer has called for Helicobacter pylori test-and-treat strategies in countries with high rates of GC. However, for countries with low rates of GC, such as most Western countries, the balance between benefits, harms and costs of screening is less clear-cut. GC is a disease with a well-characterized precancerous process, providing the basis for primary and secondary prevention efforts. However, rigorous data assessing the impact of such interventions in Western countries are lacking. In the absence of clinical trials, modelling offers a unique approach to evaluate the potential impact of various screening and surveillance interventions. In this paper, we provide an overview of modelling studies evaluating the cost-effectiveness of GC screening and surveillance in Western countries.

Gene-Specific Variation in Colorectal Cancer Surveillance Strategies for Lynch Syndrome.

BACKGROUND AND AIMS: Lynch syndrome is associated with pathogenic variants in 4 mismatch repair (MMR) genes that increase lifetime risk of colorectal cancer. Guidelines recommend intensive colorectal cancer surveillance with colonoscopy every 1-2 years starting at age 25 years for all carriers of Lynch syndrome-associated variants, regardless of gene product. We constructed a simulation model to analyze the effects of different ages of colonoscopy initiation and surveillance intervals for each MMR gene (MLH1, MSH2, MSH6, and PMS2) on colorectal cancer incidence and mortality, quality-adjusted life-years, and cost. METHODS: Using published literature, we developed a Markov simulation model of Lynch syndrome progression for patients with each MMR variant. The model simulated clinical trials of Lynch syndrome carriers, varying age of colonoscopy initiation (5-year increments from 25-40 years), and surveillance intervals (1-5 years). We assessed the optimal strategy for each gene, defined as the strategy with the highest quality-adjusted life-years and incremental cost-effectiveness ratio below a $100,000 willingness-to-pay threshold. RESULTS: Optimal surveillance for patients with pathogenic variants in the MLH1 and MSH2 genes was colonoscopy starting at age 25 years, with 1- to 2-year surveillance intervals. Initiating colonoscopy at age 35 and 40 years, with 3-year intervals, was cost-effective for patients with pathogenic variants in MSH6 or PMS2, respectively. CONCLUSIONS: We developed a simulation model to select optimal surveillance starting ages and intervals for patients with Lynch syndrome based on MMR variant. The model supports recommendations for intensive surveillance of patients with Lynch syndrome-associated variants in MLH1 or MSH2. However, for patients with Lynch syndrome-associated variants of MSH6 or PMS2, later initiation of surveillance at 35 and 40 years, respectively, and at 3-year intervals, can be considered.

Heavy Alcohol Use Is Associated With Gastric Cancer: Analysis of the National Health and Nutrition Examination Survey From 1999 to 2010.

INTRODUCTION: Evidence regarding the association between alcohol use and gastric cancer (GC) has been inconsistent. METHODS: Adults who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010 were included. Multivariable regression was used to assess the association between GC and heavy alcohol use (≥5 alcoholic drinks daily). RESULTS: Of 470,168 individuals surveyed, 342 had a history of GC. Heavy alcohol use was associated with GC (odds ratio 3.13, 95% confidence interval 1.15-8.64) on multivariable analysis. DISCUSSION: This is the largest study to our knowledge to demonstrate an association between heavy alcohol use and GC in the United States.

Prevalence of Clostridioides difficile and Other Gastrointestinal Pathogens in Patients with COVID-19.

BACKGROUND: Gastrointestinal symptoms are common in patients with COVID-19, but prevalence of co-infection with enteric pathogens is unknown. AIMS: This study assessed the prevalence of enteric infections among hospitalized patients with COVID-19. METHODS: We evaluated 4973 hospitalized patients ≥ 18 years of age tested for COVID-19 from March 11 through April 28, 2020, at two academic hospitals. The primary exposure was a positive COVID-19 test. The primary outcome was detection of a gastrointestinal pathogen by PCR stool testing. RESULTS: Among 4973 hospitalized individuals, 311 were tested for gastrointestinal infections (204 COVID-19 positive, 107 COVID-19 negative). Patients with COVID-19 were less likely to test positive compared to patients without COVID-19 (10% vs 22%, p < 0.01). This trend was driven by lower rates of non-C.difficile infections (11% vs 22% in COVID-19 positive vs. negative, respectively, p = 0.04), but not C. difficile infection (5.1% vs. 8.2%, p = 0.33). On multivariable analysis, infection with COVID-19 remained significantly associated with lower odds of concurrent GI infection (aOR 0.49, 95% CI 0.24-0.97), again driven by reduced non-C.difficile infection. Testing for both C.difficile and non-C.difficile enteric infection decreased dramatically during the pandemic. CONCLUSIONS: Pathogens aside from C.difficile do not appear to be a significant contributor to diarrhea in COVID-19 positive patients.