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.

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.

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.

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.

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.

Unique microbial profile identified in patients with gastric cancer with pathologic response to neoadjuvant chemotherapy

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Background: Microbial dysbiosis has been shown to be associated with the pathogenesis of gastric cancer (GC). However, the relationship between the GC microbiome and response to systemic therapy, such as neoadjuvant chemotherapy (NAC), is largely unknown. This study aims to explore changes in the microbiome after neoadjuvant chemotherapy, by analyzing the microbial profile of patients who received NAC and comparing differences among those with varied pathologic response to therapy. Methods: A microbiome bioinformatics pipeline using multiple next generation sequencing platforms was developed and used for analysis. GC tissue from patients who received NAC (n=101) and those who did not (n=85) were acquired at the time of surgical resection. Shannon alpha diversity plot and enrichment analyses by odds ratio were used to compare the microbial differences of the treatment cohorts. The microbial profiles of patients with pathologic response to NAC (>20% response) were characterized. Results: Of patients who received NAC, 66 (65.3%) experienced a greater than 20% response to NAC, and 35 (34.6%) demonstrated a 20% or lower response. Patients with a pathologic response to NAC were enriched for Rhizobium, Streptomyces, Comamonas, Sphingomonas, Micrococcus, Mycobacterium, Thauera, Hyphomicrobium, and Sinorhizobium (OR>4). There were no statistically significant differences in alpha diversity (p>0.05). Conclusions: Our results demonstrate that patients with a greater than 20% pathologic response to NAC have a distinct microbial enrichment compared to those with a poor pathologic response. Given the variable NAC treatment responses in GC, understanding unique microbial signatures in tumors will provide the landscape to explore key microbial contributors to GC NAC treatment response that may improve our understanding of treatment response variability among patients. [Table: see text]

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.

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.

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.

Efficacy of Endoscopic Submucosal Dissection for Superficial Gastric Neoplasia in a Large Cohort in North America

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) is a widely accepted treatment option for superficial gastric neoplasia in Asia, but there are few data on outcomes of gastric ESD from North America. We aimed to evaluate the safety and efficacy of gastric ESD in North America.

METHODS

We analyzed data from 347 patients who underwent gastric ESD at 25 centers, from 2010 through 2019. We collected data on patient demographics, lesion characteristics, procedure details and related adverse events, treatment outcomes, local recurrence, and vital status at the last follow up. For the 277 patients with available follow-up data, the median interval between initial ESD and last clinical or endoscopic evaluation was 364 days. The primary endpoint was the rate of en bloc and R0 resection. Secondary outcomes included curative resection, rates of adverse events and recurrence, and gastric cancer-related death.

RESULTS

Ninety patients (26%) had low-grade adenomas or dysplasia, 82 patients (24%) had high-grade dysplasia, 139 patients (40%) had early gastric cancer, and 36 patients (10%) had neuroendocrine tumors. Proportions of en bloc and R0 resection for all lesions were 92%/82%, for early gastric cancers were 94%/75%, for adenomas and low-grade dysplasia were 93%/ 92%, for high-grade dysplasia were 89%/ 87%, and for neuroendocrine tumors were 92%/75%. Intraprocedural perforation occurred in 6.6% of patients; 82% of these were treated successfully with endoscopic therapy. Delayed bleeding occurred in 2.6% of patients. No delayed perforation or procedure-related deaths were observed. There were local recurrences in 3.9% of cases; all occurred after non-curative ESD resection. Metachronous lesions were identified in 14 patients (6.9%). One of 277 patients with clinical follow up died of metachronous gastric cancer that occurred 2.5 years after the initial ESD.

CONCLUSIONS

ESD is a highly effective treatment for superficial gastric neoplasia and should be considered as a viable option for patients in North America. The risk of local recurrence is low and occurs exclusively after non-curative resection. Careful endoscopic surveillance is necessary to identify and treat metachronous lesions.

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.

Disease Course and Outcomes of COVID-19 Among Hospitalized Patients With Gastrointestinal Manifestations

BACKGROUND & AIMS

Our understanding of outcomes and disease time course of COVID-19 in patients with gastrointestinal (GI) symptoms remains limited. In this study we characterize the disease course and severity of COVID-19 among hospitalized patients with gastrointestinal manifestations in a large, diverse cohort from the Unites States.

METHODS

This retrospective study evaluated hospitalized individuals with COVID-19 between March 11 and April 28, 2020 at two affiliated hospitals in New York City. We evaluated the association between GI symptoms and death, and also explored disease duration, from symptom onset to death or discharge.

RESULTS

Of 2804 patients hospitalized with COVID-19, the 1,084 (38.7%) patients with GI symptoms were younger (aOR for age ≥75, 0.59; 95% CI, 0.45-0.77) and had more co-morbidities (aOR for modified Charlson comorbidity score ≥2, 1.22; 95% CI, 1.01-1.48) compared to those without GI symptoms. Individuals with GI symptoms had better outcomes, with a lower likelihood of intubation (aHR, 0.66; 95% CI, 0.55-0.79) and death (aHR, 0.71; 95% CI, 0.59-0.87), after adjusting for clinical factors. These patients had a longer median disease course from symptom onset to discharge (13.8 vs 10.8 days, log-rank p = .048; among 769 survivors with available symptom onset time), which was driven by longer time from symptom onset to hospitalization (7.4 vs 5.4 days, log-rank P < .01).

CONCLUSION

Hospitalized patients with GI manifestations of COVID-19 have a reduced risk of intubation and death, but may have a longer overall disease course driven by duration of symptoms prior to hospitalization.

Risk of Adverse Outcomes in Hospitalized Patients With Autoimmune Disease and COVID-19: A Matched Cohort Study From New York City

OBJECTIVE

To examine the effect of autoimmune (AI) disease on the composite outcome of intensive care unit (ICU) admission, intubation, or death from COVID-19 in hospitalized patients.

METHODS

Retrospective cohort study of 186 patients hospitalized with COVID-19 between March 1, 2020, and April 15, 2020 at NewYork-Presbyterian Hospital/Columbia University Irving Medical Center. The cohort included 62 patients with AI disease and 124 age- and sex-matched controls. The primary outcome was a composite of ICU admission, intubation, and death, with secondary outcome as time to in-hospital death. Baseline demographics, comorbidities, medications, vital signs, and laboratory values were collected. Conditional logistic regression and Cox proportional hazards regression were used to assess the association between AI disease and clinical outcomes.

RESULTS

Patients with AI disease were more likely to have at least one comorbidity (87.1% vs 74.2%, P = 0.04), take chronic immunosuppressive medications (66.1% vs 4.0%, P < 0.01), and have had a solid organ transplant (16.1% vs 1.6%, P < 0.01). There were no significant differences in ICU admission (13.7% vs 19.4%, P = 0.32), intubation (13.7% vs 17.7%, P = 0.47), or death (16.1% vs 14.5%, P = 0.78). On multivariable analysis, patients with AI disease were not at an increased risk for a composite outcome of ICU admission, intubation, or death (ORadj 0.79, 95% CI 0.37-1.67). On Cox regression, AI disease was not associated with in-hospital mortality (HRadj 0.73, 95% CI 0.33-1.63).

CONCLUSION

Among patients hospitalized with COVID-19, individuals with AI disease did not have an increased risk of a composite outcome of ICU admission, intubation, or death.

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.

Low sodium diet for gastric cancer prevention in the United States: Results of a Markov model

Background and Aims

High sodium consumption has been associated with an increased risk of gastric cancer. The mean daily sodium intake in the United States substantially exceeds the national recommended amount. The low sodium‐DASH diet has been shown to decrease the risk of cardiovascular disease in the United States, but its impact on gastric cancer has not been well studied. We therefore aimed to model the impact and cost‐effectiveness of the low sodium‐DASH diet for gastric cancer prevention in the U.S. population.

Methods

A Markov cohort state‐transition model was developed to simulate the impact of the low sodium‐DASH diet on gastric cancer outcomes for the average 40‐year‐old in the United States compared to no intervention. Primary outcomes of interest were gastric cancer incidence and incremental cost‐effectiveness ratios (ICER).

Results

Our model found that compared to the no intervention cohort, the risk of gastric cancer decreased by 24.8% for males and 21.2% for females on the low sodium‐DASH diet. 27 cases and 14 cases per 10,000 individuals were prevented for males and females, respectively, in the intervention group. The ICER for the low sodium‐DASH diet strategy was $287,726 for males and $423,878 for females compared to the no intervention strategy.

Conclusions

Using a Markov model of gastric cancer risk, we found that adherence to a low sodium‐DASH diet could decrease the risk of gastric cancer. This intervention was not cost‐effective due to the high cost of a low sodium‐DASH accordant diet, but significantly improved for high‐risk populations and when the cost of the diet became slightly more affordable.

Racial and ethnic disparities in mortality from gastric and esophageal adenocarcinoma

Background

Racial/ethnic differences in mortality have not been well studied for either non‐cardia gastric cancer (NCGC) or cardia gastric cancer (CGC). The aim of this study was to examine the US mortality rates for these cancer subtypes, as well as esophageal adenocarcinoma (EAC) as a comparator.

Methods

We identified 14 164 individuals who died from NCGC, 5235 from CGC, and 13 982 from EAC in the Surveillance, Epidemiology, and End Results database between 2004 and 2016. Age‐adjusted incidence‐based mortality rates and corresponding annual percent changes (APCs) were calculated. Analyses were stratified by race/ethnicity, age, and stage of disease at diagnosis.

Results

The mortality rate in NCGC was two‐ to threefold higher in blacks, Hispanics, and Asians/Pacific Islanders (PI) than non‐Hispanic whites, and was significant across all age groups and stages of disease (P < .01). Mortality in CGC was higher in non‐Hispanic whites than blacks and Asians/PI, particularly in individuals in the 50‐64 year age group and those with stage IV disease. Mortality in EAC was two‐ to sixfold higher in non‐Hispanic whites than all other groups across all age groups and stages of disease. From 2004 to 2016, mortality rates were stable across all racial/ethnic groups in NCGC and CGC, and in minority groups with EAC, but have been rising in non‐Hispanic whites with EAC (APC 3.03, 95% CI 0.17‐5.96).

Conclusions

This is the largest study of incidence‐based mortality in CGC and NCGC and demonstrates racial/ethnic differences in mortality between these subtypes. Mortality rates for NCGC are highest in minority groups, and have been stable in recent years despite declining incidence. Mortality rates for CGC are marginally higher in middle‐aged non‐Hispanic whites with advanced disease, though have remained stable. In contrast, mortality in EAC has been rising for non‐Hispanic whites, in parallel to incidence. Further studies are needed to refine prevention strategies for high‐risk individuals dying from these specific cancer subtypes.

Optimal Timing of Total Gastrectomy to Prevent Diffuse Gastric Cancer in Individuals With Pathogenic Variants in CDH1

BACKGROUND & AIMS

Carriers of pathogenic variants in CDH1 have a high risk of hereditary diffuse gastric cancer (HDGC). Guidelines recommend prophylactic total gastrectomy (PTG) at age 20-30 years, although there is controversy over the optimal age. We developed a simulation model to analyze the effects of PTG at different ages on quality-adjusted life-years (QALYs), cancer mortality, and life expectancy.

METHODS

We used a Markov model of HDGC progression associated with pathogenic variants in CDH1 to simulate outcomes of hypothetical cohorts with different ages at time of PTG (ages 20-79 years). Model inputs including health state transition probabilities, mortality and complication rates, quality of life utility values, and endoscopic surveillance sensitivity were derived from publications. The primary outcome, used to determine the optimal strategy, was age at which PTG yielded the highest QALYs. Secondary outcomes were cancer mortality and unadjusted life-years.

RESULTS

Our model found that for men, the optimal age for PTG is 39 years, resulting in 32.01 incremental QALYs, 58.81 life-years (biologic age, 72.81 years), and lifetime cancer mortality of 8.5%. Incorporating endoscopic surveillance prior to PTG decreased cancer mortality to 6.7%, but had lower QALYs (31.59). PTG at age 30 reduced cancer mortality to 3.2%, with 31.45 incremental QALYs. For women, the optimal age for PTG was calculated to be 30 years, with 33.09 incremental QALYs, 66.17 life-years (biologic age, 80.17 years), and lifetime cancer mortality of 1.6%. Addition of endoscopic surveillance did not decrease the risk of HDGC mortality in women.

CONCLUSIONS

Using a Markov model of HDGC progression associated with pathogenic variants in CDH1 to simulate outcomes, we found the optimal ages for PTG to be 39 years for men and 30 years for women, when QALYs are the primary endpoint. These ages for PTG are older than those of current recommendations.

Cost-effectiveness Evaluation of Targeted Surgical and Endoscopic Therapies for Early Colorectal Adenocarcinoma Based on Biomarker Profiles

IMPORTANCE

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality in the United States. The prognosis for patients with CRC varies widely, but new prognostic biomarkers provide the opportunity to implement a more individualized approach to treatment selection.

OBJECTIVE

To assess the cost-effectiveness of 3 therapeutic strategies, namely, endoscopic therapy (ET), laparoscopic colectomy (LC), and open colectomy (OC), for patients with T1 CRC with biomarker profiles that prognosticate varying levels of tumor progression in the US payer perspective.

DESIGN, SETTING, AND PARTICIPANTS

In this economic evaluation study, a Markov model was developed for the cost-effectiveness analysis. Risks of all-cause mortality and recurrent cancer after ET, LC, or OC were estimated with a 35-year time horizon. Quality of life was based on EuroQoL 5 Dimensions scores reported in the published literature. Hospital and treatment costs reflected Medicare reimbursement rates. Deterministic and probabilistic sensitivity analyses were performed. Data from patients with T1 CRC and 6 biomarker profiles that included adenomatous polyposis coli (APC), TP53 and/or KRAS, or BRAFV600E were used as inputs for the model. Data analyses were conducted from February 27, 2019, to May 13, 2019.

EXPOSURES

Endoscopic therapy, LC, and OC.

MAIN OUTCOMES AND MEASURES

The primary outcomes were unadjusted life-years, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER) between competing treatment strategies.

RESULTS

Endoscopic therapy had the highest QALYs and the lowest cost and was the dominant treatment strategy for T1 CRC with the following biomarker profiles: BRAFV600E, APC(1)/KRAS/TP53, APC(2) or APC(2)/KRAS or APC(2)/TP53, or APC(1) or APC(1)/KRAS or APC(1)/TP53. The QALYs gained ranged from 16.97 to 17.22, with costs between $68 902.75 and $77 784.53 in these subgroups. For the 2 more aggressive biomarker profiles with worse prognoses (APC(2)/KRAS/TP53 and APCwt [wild type]), LC was the most effective strategy (with 16.45 and 16.61 QALYs gained, respectively) but was not cost-effective. Laparoscopic colectomy cost $65 234.87 for APC(2)/KRAS/TP53 and $71 250.56 for APCwt, resulting in ICERs of $113 290 per QALY and $178 765 per QALY, respectively.

CONCLUSIONS AND RELEVANCE

This modeling analysis found that ET was the most effective strategy for patients with T1 CRC with less aggressive biomarker profiles. For patients with more aggressive profiles, LC was more effective but was costly, rendering ET the cost-effective option. This study highlights the potential utility of prognostic biomarkers in T1 CRC treatment selection.

Cost-Effectiveness Analysis of Biomarker-Guided Treatment for Metastatic Gastric Cancer in the Second-Line Setting

BACKGROUND

The 5-year survival rate of patients with metastatic gastric cancer (GC) is only 5%. However, trials have demonstrated promising antitumor activity for targeted therapies/immunotherapies among chemorefractory metastatic GC patients. Pembrolizumab has shown particular efficacy among patients with programmed death ligand-1 (PD-L1) expression and high microsatellite instability (MSI-H). The aim of this study was to assess the effectiveness and cost-effectiveness of biomarker-guided second-line GC treatment.

METHODS

We constructed a Markov decision-analytic model using clinical trial data. Our model compared pembrolizumab monotherapy and ramucirumab/paclitaxel combination therapy for all patients and pembrolizumab for patients based on MSI status or PD-L1 expression. Paclitaxel monotherapy and best supportive care for all patients were additional comparators. Costs of drugs, treatment administration, follow-up, and management of adverse events were estimated from a US payer perspective. The primary outcomes were quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) with a willingness-to-pay threshold of $100,000/QALY over 60 months. Secondary outcomes were unadjusted life years (survival) and costs. Deterministic and probabilistic sensitivity analyses were performed to evaluate model uncertainty.

RESULTS

The most effective strategy was pembrolizumab for MSI-H patients and ramucirumab/paclitaxel for all other patients, adding 3.8 months or 2.0 quality-adjusted months compared to paclitaxel. However, this strategy resulted in a prohibitively high ICER of $1,074,620/QALY. The only cost-effective strategy was paclitaxel monotherapy for all patients, with an ICER of $53,705/QALY.

CONCLUSION

Biomarker-based treatments with targeted therapies/immunotherapies for second-line metastatic GC patients substantially improve unadjusted and quality-adjusted survival but are not cost-effective at current drug prices.

Increased Healthcare Utilization by Patients With Inflammatory Bowel Disease Covered by Medicaid at a Tertiary Care Center

BACKGROUND

Low socioeconomic status has been linked with numerous poor health outcomes, but data are limited regarding the impact of insurance status on inflammatory bowel disease (IBD) outcomes. We aimed to characterize utilization of healthcare resources by IBD patients based on health insurance status, using Medicaid enrollment as a proxy for low socioeconomic status.

METHODS

We retrospectively identified adult patients with IBD engaged in a colorectal cancer surveillance colonoscopy program from July 2007 to June 2017. Our primary outcomes included emergency department (ED) visits, inpatient hospitalizations, biologic infusions, and steroid exposure, stratified by insurance status. We compared patients who had ever been enrolled in Medicaid with all other patients.

RESULTS

Of 947 patients with IBD, 221 (23%) had been enrolled in Medicaid. Compared with patients with other insurance types, patients with Medicaid had higher rates of ever being admitted to the hospital (77.6% vs 42.6%, P < 0.0001) or visiting the ED (90.5% vs 38.4%, P < 0.0001). When adjusted for sex, age at first colonoscopy, and ethnicity, patients with Medicaid had a higher rate of inpatient hospitalizations (Rate ratio [RR] 2.95; 95% CI 2.59-3.36) and ED visits (RR 4.24; 95% CI 3.82-4.70) compared to patients with other insurance. Patients with Medicaid had significantly higher prevalence of requiring steroids (62.4% vs 37.7%, P < 0.0001), and after adjusting for the same factors, the odds of requiring steroids in the patients with Medicaid was increased (OR 3.77; 95% CI 2.53-5.62).

CONCLUSIONS

Medicaid insurance was a significant predictor of IBD care and outcomes. Patients with Medicaid may have less engagement in IBD care and seek emergency care more often.

Second-line treatment of metastatic gastric cancer in the era of predictive biomarkers: A cost-effectiveness analysis

e15517

Background: Gastric cancer is the third leading cause of cancer-related mortality, with only a 30% five-year survival rate. Patients who progress after one round of systemic therapy face an especially poor prognosis. The National Comprehensive Cancer Network guidelines include both pembrolizumab (PEM) and ramucirumab plus paclitaxel (RAM/PAC) as second-line (2L) therapy for gastric cancer based on data from the Phase II KEYNOTE-059 and Phase III RAINBOW trials, respectively. Recently, the Phase III KEYNOTE-061 trial reported on the effectiveness of PEM for patients with programmed death-ligand 1 (PD-L1) expression and high microsatellite instability (MSI-H). Given the high prices of targeted therapies, it is important to determine if cost-effectiveness is possible using personalized treatment strategies. The aim of this study was to assess the cost-effectiveness of these regimens in both the general patient population and specific biomarker populations. Methods: A decision-analytic (Markov) model was constructed using data from the KEYNOTE-059, KEYNOTE-061, RAINBOW, and REGARD trials. The analysis compared PEM and RAM/PAC for all patients, as well as PEM for patients based on MSI status or PD-L1 expression (combined positive score of 1% or 10%) in the 2L setting. Comparators were paclitaxel monotherapy (PAC) for all patients and best supportive care (BSC) for all patients. Costs (USD) and utility values were estimated from Medicare and the literature. The primary outcome was the incremental cost-effectiveness ratio (ICER) with a willingness-to-pay (WTP) threshold of $100,000. Results: The only cost-effective strategy was PAC monotherapy for all patients, with an ICER of $53,705/QALY. PEM for MSI-H patients and RAM/PAC for microsatellite stable patients was the most effective strategy (greatest QALYs), but was not cost-effective with an ICER of $1,074,620/QALY. Conclusions: Despite their effectiveness, PEM and RAM/PAC are not cost-effective as 2L treatments for metastatic gastric cancer. Although personalizing treatment based on biomarkers improved cost-effectiveness, the ICERs surpassed the WTP threshold at current drug prices.

Systematic review with meta-analysis: the prevalence of coeliac disease in patients with osteoporosis

BACKGROUND

Earlier studies have produced highly varying risk estimates for the prevalence of coeliac disease (CD) in osteoporosis.

AIMS

To investigate the prevalence of CD among individuals with osteoporosis.

METHODS

We conducted a systematic review of articles published in PubMed, Medline or EMBASE through May 2017 to identify studies looking at prevalence of CD in patients with osteoporosis. Search terms included "coeliac disease" combined with "fractures", "bone disease", "bone density", "densitometry", "osteoporos*", "osteomal*", "osteodys" or "dexa" or "dxa" or "skelet". Non-English papers with English-language abstracts were included. We used fixed-effects inverse variance-weighted models, and tested heterogeneity through subgroup analysis as well as through meta-regression.

RESULTS

We identified eight relevant studies, comprising data from 3188 individuals with osteoporosis. Of these, 59 individuals (1.9%) had CD. A weighted pooled analysis demonstrated biopsy-confirmed CD in 1.6% (95% CI = 1.1%-2.0%) of individuals with osteoporosis. The heterogeneity was moderate (I²  = 40.1%), and influenced by the underlying CD prevalence in the general population. After adding four studies (n = 814) with CD defined as positive tissue transglutaminase or endomysial antibodies, the pooled prevalence was comparable (1.6%; 95% CI = 1.2%-2.0%).

CONCLUSIONS

About 1 in 62 individuals with osteoporosis, or 1.6%, have biopsy-verified CD. This prevalence is comparable to that in the general population. These findings argue against routinely screening patients with osteoporosis for CD, which is contrary to current guideline recommendations. Additional studies are needed to determine the true utility of such screening programs.

Prevalence of Celiac Disease in Patients With Iron Deficiency Anemia-A Systematic Review With Meta-analysis

BACKGROUND & AIMS

Anemia is common in patients with celiac disease (CD) and a frequent mode of presentation. Guidelines recommend screening patients with iron-deficiency anemia (IDA) for CD. However, the reported prevalence of CD in patients with IDA varies. We performed a systematic review to determine the prevalence of biopsy-verified CD in patients with IDA.

METHODS

We performed a systematic review of articles published in PubMed Medline or EMBASE through July 2017 for the term "celiac disease" combined with "anemia" or "iron deficiency." We used fixed-effects inverse variance-weighted models to measure the pooled prevalence of CD. Meta-regression was used to assess subgroup heterogeneity.

RESULTS

We identified 18 studies composed of 2998 patients with IDA for inclusion in our analysis. Studies originated from the United Kingdom, United States, Italy, Turkey, Iran, and Israel. The crude unweighted prevalence of CD was 4.8% (n = 143). Using a weighted pooled analysis, we found a prevalence of biopsy-confirmed CD of 3.2% (95% confidence interval = 2.6-3.9) in patients with IDA. However, heterogeneity was high (I² = 67.7%). The prevalence of CD was not significantly higher in studies with a mean participant age older or younger than 18 years or in studies with a mixed-sex vs female-predominant (≥60%) population. On meta-regression, year of publication, female proportion, age at CD testing, and prevalence in the general population were not associated with the prevalence of CD in patients with IDA. In the 8 studies fulfilling all our quality criteria, the pooled prevalence of CD was 5.5% (95% confidence interval = 4.1-6.9).

CONCLUSIONS

In a systematic review and meta-analysis, we found that approximately 1 in 31 patients with IDA have histologic evidence of CD. This prevalence value justifies the practice of testing patients with IDA for CD.

Nationwide population-based cohort study of celiac disease and risk of Ehlers-Danlos syndrome and joint hypermobility syndrome

BACKGROUND

Patients with celiac disease (CD) often have articular complaints, and small prior studies suggest an association with Ehlers-Danlos syndrome (EDS)/joint hypermobility syndrome (JHS).

AIMS

This study examines the risks of EDS/JHS in patients with CD.

METHODS

This cohort study compared all individuals in Sweden diagnosed with CD based on small intestinal biopsy between 1969-2008 (n=28,631) to 139,832 matched reference individuals, and to a second reference group undergoing biopsy without having CD (n=16,104). Rates of EDS/JHS were determined based on diagnostic codes in the Swedish Patient Register. Hazard ratios (HRs) for EDS/JHS were estimated through Cox regression.

RESULTS

There are 45 and 148 cases of EDS/JHS in patients with CD and reference individuals, respectively. This corresponds to a 49% increased risk of EDS/JHS in CD (95%CI=1.07-2.07). The HR for EDS was 2.43 (95%CI=1.20-4.91) and for JHS 1.34 (95%CI=0.93-1.95). Compared to reference individuals undergoing intestinal biopsy, CD was not a risk factor for EDS/JHS. A stronger association was seen in patients initially diagnosed with EDS/JHS and subsequently diagnosed with CD (odds ratio=2.29; 95%CI=1.21-4.34).

CONCLUSIONS

Individuals with CD have higher risk of EDS/JHS than the general population, which may be due to surveillance bias or factors intrinsic to celiac development.

Prevalence of Celiac Disease in Patients with Autoimmune Thyroid Disease: A Meta-Analysis

BACKGROUND

Several screening studies have indicated an increased prevalence of celiac disease (CD) among individuals with autoimmune thyroid disease (ATD), but estimates have varied substantially.

OBJECTIVE

The aim of this study was to examine the prevalence of CD in patients with ATD.

METHOD

A systematic review was conducted of articles published in PubMed Medline or EMBASE until September 2015. Non-English papers with English-language abstracts were also included, as were research abstracts without full text available when relevant data were included in the abstract. Search terms included "celiac disease" combined with "hypothyroidism" or "hyperthyroidism" or "thyroid disease." Fixed-effects inverse variance-weighted models were used. Meta-regression was used to examine heterogeneity in subgroups.

RESULTS

A pooled analysis, based on 6024 ATD patients, found a prevalence of biopsy-confirmed CD of 1.6% [confidence interval (CI) 1.3-1.9%]. Heterogeneity was large (I(2) = 70.7%). The prevalence was higher in children with ATD (6.2% [CI 4.0-8.4%]) than it was in adults (2.7%) or in studies examining both adults and children (1.0%). CD was also more prevalent in hyperthyroidism (2.6% [CI 0.7-4.4%]) than it was in hypothyroidism (1.4% [CI 1.0-1.9%]).

CONCLUSIONS

About 1/62 patients with ATD have biopsy-verified CD. It is argued that patients with ATD should be screened for CD, given this increased prevalence.

Clinical grade manufacturing of human alloantigen-reactive regulatory T cells for use in transplantation

Regulatory T cell (Treg) therapy has the potential to induce transplantation tolerance so that immunosuppression and associated morbidity can be minimized. Alloantigen-reactive Tregs (arTregs) are more effective at preventing graft rejection than polyclonally expanded Tregs (PolyTregs) in murine models. We have developed a manufacturing process to expand human arTregs in short-term cultures using good manufacturing practice-compliant reagents. This process uses CD40L-activated allogeneic B cells to selectively expand arTregs followed by polyclonal restimulation to increase yield. Tregs expanded 100- to 1600-fold were highly alloantigen reactive and expressed the phenotype of stable Tregs. The alloantigen-expanded Tregs had a diverse TCR repertoire. They were more potent than PolyTregs in vitro and more effective at controlling allograft injuries in vivo in a humanized mouse model.

Induction of FoxP3+CD4+CD25+ regulatory T cells by a bone marrow population distinct from plasmacytoid-DC

Facilitating cells (FC) are bone marrow-derived cells that facilitate allogeneic hematopoietic stem cell (SC) engraftment and induce transplantation tolerance without causing graft vs. host disease. Although there is evidence for FC directing the development of FoxP3+CD4+CD25+ regulatory T cells, the specific FC subsets that control regulatory T cell development have not been defined. The current study investigates the role of FC-CD3epsilon+ and FC-CD3epsilon- subpopulations in the development of FoxP3+CD4+CD25+ regulatory T cells. Here, we demonstrate that the induction of FoxP3+CD4+CD25+ regulatory T cells in coculture is mediated by not only the FC-CD3epsilon- subset but also the FC-CD3epsilon+ subset, which is distinct from plasmacytoid precursor dendritic cells (p-preDC). The identification of cell populations distinct from p-preDC that efficiently induce the generation of FoxP3+CD4+CD25+ regulatory T cells may prove useful for future therapeutic applications for the induction of tolerance following allogeneic SC transplantation.

Acetylation of p53 augments its site-specific DNA binding both in vitro and in vivo

p53 promotes tumor suppression through its ability to function as a transcriptional factor and is activated by posttranslational modifications that include acetylation. Our earlier study demonstrated that p53 acetylation can enhance its sequence-specific DNA binding in vitro, and this notion was later confirmed in several other studies. However, a recent study has reported that in vitro acetylation of p53 fails to stimulate its DNA binding to large DNA fragments, raising an important issue that requires further investigation. Here, we show that unacetylated p53 is able to bind weakly to its consensus site within the context of large DNA fragments, although it completely fails to bind the same site within short oligonucleotide probes. Strikingly, by using highly purified and fully acetylated p53 proteins obtained from cells, we show that acetylation of the C-terminal domain can dramatically enhance site-specific DNA binding on both short oligonucleotide probes and long DNA fragments. Moreover, endogenous p53 apparently can be fully acetylated in response to DNA damage when both histone deacetylase complex 1 (HDAC1)- and Sir2-mediated deacetylation are inhibited, indicating dynamic p53 acetylation and deacetylation events during the DNA damage response. Finally, we also show that acetylation of endogenous p53 indeed significantly augments its ability to bind an endogenous target gene and that p53 acetylation levels correlate well with p53-mediated transcriptional activation in vivo. Thus, our results clarify some of the confusion surrounding acetylation-mediated effects on p53 binding to DNA and suggest that acetylation of p53 in vivo may contribute, at least in part, to its transcriptional activation functions.