Clinical and socioeconomic determinants of survival in biliary tract adenocarcinomas.

BACKGROUND: Despite advances in detection and treatments, biliary tract cancers continue to have poor survival outcomes. Currently, there is limited data investigating the significance of socioeconomic status, race/ethnicity, and environmental factors in biliary tract cancer survival. AIM: To investigate how socioeconomic status and race/ethnicity are associated with survival. METHODS: Data from the Surveillance, Epidemiology, and End Results database for biliary and gallbladder adenocarcinomas were extracted from 1975 to 2016. Socioeconomic data included smoking, poverty level, education, adjusted household income, and percentage of foreign-born persons and urban population. Survival was calculated with Cox proportional hazards models for death in the 5-year period following diagnosis. RESULTS: Our study included 15883 gallbladder, 11466 intrahepatic biliary, 12869 extrahepatic biliary and 7268 ampulla of Vater adenocarcinoma cases. When analyzing county-specific demographics, patients from counties with higher incomes were associated with higher survival rates [hazard ratio (HR) = 0.97, P <0.05]. Similarly, counties with a higher percentage of patients with a college level education and counties with a higher urban population had higher 5-year survival rates (HR = 0.96, P = 0.002 and HR = 0.97, P = 0.004, respectively). CONCLUSION: Worse survival outcomes were observed in lower income counties while higher income and education level were associated with higher 5-year overall survival among gallbladder and biliary malignancies.

Impact of COVID-19 Treatment on Real-World Outcomes in Inflammatory Bowel Disease.

BACKGROUND: While there are multiple safe and effective agents for COVID-19 treatment, their impact in inflammatory bowel disease (IBD) remains uncertain. AIMS: Our objective was to assess the effects of these therapies on both IBD and COVID outcomes. METHODS: A single-center retrospective study of adult patients with IBD who contracted COVID-19 between 12/2020 and 11/2022 was performed. Patients were stratified by COVID-19 treatment (antivirals and/or intravenous antibodies) vs no therapy. The primary outcome was the development of severe COVID-19 infection, defined by need for supplemental oxygen, corticosteroids and/or antibiotics, or hospitalization. Secondary outcomes included rates of withholding advanced IBD therapy (defined as biologic agents or small molecules) and of post-COVID-19 IBD flare. RESULTS: Of 127 patients with COVID-19 infection, 70% were on advanced therapies, 35% received COVID-19 treatment, and 15% developed severe COVID-19. Those treated for COVID-19 were more likely to be on corticosteroids [odds ratio (OR) 4.61, 95% confidence interval (CI) 1.72-12.39, p = 0.002] or advanced IBD therapies (OR 2.78, 95% CI 1.04-7.43, p = 0.041). After adjusting for age, race, sex, corticosteroid use, obesity, COVID-19 vaccination status, and severe COVID-19 infection, those treated for COVID-19 were more likely to have IBD therapy held (OR 6.95, 95% CI 1.72-28.15, p = 0.007). There was no significant difference in rates of post-COVID-19 IBD flares or severe COVID-19 infection. There were no COVID-related deaths. CONCLUSIONS: Patients with IBD on advanced therapies were frequently treated for acute COVID-19. Although COVID-19 treatment was associated with temporary withholding of IBD therapy, it did not result in increased IBD flares.

Appendiceal adenocarcinoma is associated with better prognosis than cecal adenocarcinoma: a population-based comparative survival study.

OBJECTIVE: Although appendiceal cancer remains a rare gastrointestinal malignancy compared with colorectal cancer, incidence rates of appendiceal cancer have increased in the last two decades. Appendiceal and cecal adenocarcinomas have distinct genomic profiles, but chemotherapy protocols for these malignancies are the same and survival outcomes between them have not been compared extensively. To this end, we conducted a comparative survival analysis of appendiceal and cecal adenocarcinomas. DESIGN: Using the Surveillance, Epidemiology and End Results (SEER) database, we identified individuals ≥30 years of age with appendiceal or cecal adenocarcinoma from 1975 to 2016. Demographic, clinical and county-level socioeconomic data were extracted using SEER*Stat software. Survival was compared by Mantel-Haenszel log-rank test, and survival curves were generated using the Kaplan-Meier method. Relative HRs for death in the 5-year period following diagnosis were calculated using multivariable Cox regression analysis, adjusted for all other covariates. The significance level was set at p<0.05 for two-tailed tests. Data were analysed using SAS V.9.4 and R software. RESULTS: We identified 6491 patients with appendiceal adenocarcinoma and 99 387 patients with cecal adenocarcinoma. Multivariable Cox regression analysis demonstrated significantly higher cancer-specific and overall survival in appendiceal adenocarcinoma compared with cecal adenocarcinoma. Male sex, older age, earlier year of diagnosis, black race, single marital status, non-Hispanic ethnicity, and non-mucinous histology were associated with increased mortality rates. In addition, counties with lower percentage of individuals below the poverty line and higher colorectal cancer screening rates had better survival. CONCLUSION: This is the first study to show greater survival in appendiceal adenocarcinoma compared with cecal adenocarcinoma. We also highlighted novel associations of county-level socioeconomic factors with increased mortality in appendiceal adenocarcinoma. Future efforts to develop targeted molecular therapies and reduce socioeconomic barriers to diagnosis and treatment are warranted to improve survival.

Anal adenocarcinoma: case report, literature review and comparative survival analysis.

INTRODUCTION: Anal adenocarcinoma is a rare malignancy with a poor prognosis. METHODS: We present a case of rare anal adenocarcinoma in a patient with normal screening colonoscopy. Using the Surveillance, Epidemiology and End Result database between 2000 and 2016, we performed survival analysis among individuals>20 years old comparing anal and rectal cancers. RESULTS: Survival analysis showed that anal adenocarcinoma is associated with worse outcomes compared with rectal adenocarcinoma and anal squamous cell carcinoma. DISCUSSION: This case and survival data illustrate the importance of prompt investigation of symptoms irrespective of colorectal cancer screening status with careful attention to examination of the anal area.

Calcium and 1,25-dihydroxyvitamin D3 modulate genes of immune and inflammatory pathways in the human colon: a human crossover trial.

BACKGROUND: A high dietary calcium intake with adequate vitamin D status has been linked to lower colorectal cancer risk, but the mechanisms of these effects are poorly understood. OBJECTIVE: The objective of this study was to elucidate the effects of a Western-style diet (WD) and supplemental calcium and/or 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the colorectal mucosa. DESIGN: We conducted 2 crossover trials to define molecular pathways in the human colorectum altered by 1) a 4-wk WD supplemented with and without 2 g calcium carbonate/d and 2) a 4-wk WD supplemented with 1,25(OH)2D3 (0.5 µg/d) with or without 2 g calcium carbonate/d. The primary study endpoint was genome-wide gene expression in biopsy specimens of the rectosigmoid colonic mucosa. Serum and urinary calcium concentrations were also measured. RESULTS: Changes in urinary calcium accurately reflected calcium consumption. The WD induced modest upregulation of genes involved in inflammatory pathways, including interferon signaling, and calcium supplementation reversed these toward baseline. In contrast, supplementation of the WD with 1,25(OH)2D3 induced striking upregulation of genes involved in inflammation, immune response, extracellular matrix, and cell adhesion. Calcium supplementation largely abrogated these changes. CONCLUSIONS: Supplementing 1,25(OH)2D3 to a WD markedly upregulated genes in immune response and inflammation pathways, which were largely reversed by calcium supplementation. This study provides clinical trial evidence of global gene expression changes occurring in the human colorectum in response to calcium and 1,25(OH)2D3 intervention. One action of 1,25(OH)2D3 is to upregulate adaptive immunity. Calcium appears to modulate this effect, pointing to its biological interaction in the mucosa. This trial was registered at clinicaltrials.gov as NCT00298545 Trial protocol is available at http://clinicalstudies.rucares.org (protocol numbers PHO475 and PHO554).

Quantification of Adequate Bowel Preparation for Screening or Surveillance Colonoscopy in Men.

BACKGROUND & AIMS: Bowel preparation is defined as adequate if it is sufficient for identification of polyps greater than 5 mm. However, adequate preparation has not been quantified. We performed a prospective observational study to provide an objective definition of adequate preparation, based on the Boston Bowel Prep Scale (BBPS, which consists of 0-3 points for each of 3 colon segments). METHODS: We collected data from 438 men who underwent screening or surveillance colonoscopies and then repeat colonoscopy examinations within 60 days by a different blinded endoscopist (1161 colon segments total) at the West Haven Veterans Affairs Medical Center from January 2014 to February 2015. Missed polyps were defined as those detected on the second examination of patients with the best possible bowel preparation (colon segment BBPS score of 3) on the second examination. The primary outcome was the proportion of colon segments with adenomas larger than 5 mm that were missed in the first examination. We postulated that the miss rate was noninferior for segments with BBPS scores of 2 vs those with BBPS scores of 3 (noninferiority margin, <5%). Our secondary hypotheses were that miss rates were higher in segments with BBPS scores of 1 vs those with scores of 3 or of 2. RESULTS: The adjusted proportion with missed adenomas greater than 5 mm was noninferior for segments with BBPS scores of 2 (5.2%) vs those with BBPS scores of 3 (5.6%) (a difference of -0.4%; 95% confidence interval [CI], -2.9% to 2.2%). Of study subjects, 347 (79.2%) had BBPS scores of 2 or greater in all segments on the initial examination. A higher proportion of segments with BBPS scores of 1 had missed adenomas larger than 5 mm (15.9%) than segments with BBPS scores of 3 (5.6%) (a difference of 10.3%; 95% CI, 2.7%-17.9%) or 2 (5.2%) (a difference of 10.7%; 95% CI, 3.2%-18.1%). Screening and surveillance intervals based solely on the findings at the first examination would have been incorrect for 16.3% of patients with BBPS scores of 3 in all segments, for 15.3% with BBPS scores of 2 or 3 in all segments, and for 43.5% of patients with a BBPS score of 1 in 1 or more segments. CONCLUSIONS: Patients with BBPS scores of 2 or 3 for all colon segments have adequate bowel preparation for the detection of adenomas larger than 5 mm and should return for screening or surveillance colonoscopy at standard guideline-recommended intervals. Colon segments with a BBPS score of 1 have a significantly higher rate of missed adenomas larger than 5 mm than segments with scores of 2 or 3. This finding supports a recommendation for early repeat colonoscopic evaluation in patients with a BBPS score of 0 or 1 in any colon segment.

Pigment Epithelium-Derived Factor (PEDF) Inhibits Wnt/ß-catenin Signaling in the Liver.

BACKGROUND & AIMS: Pigment epithelium-derived factor (PEDF) is a secretory protein that inhibits multiple tumor types. PEDF inhibits the Wnt coreceptor, low-density lipoprotein receptor-related protein 6 (LRP6), in the eye, but whether the tumor-suppressive properties of PEDF occur in organs such as the liver is unknown. METHODS: Wnt-dependent regulation of PEDF was assessed in the absence and presence of the Wnt coreceptor LRP6. Whole genome expression analysis was performed on PEDF knockout (KO) and control livers (7 months). Interrogation of Wnt/ß-catenin signaling was performed in whole livers and human hepatocellular carcinoma (HCC) cell lines after RNA interference of PEDF and restoration of a PEDF-derived peptide. Western diet feeding for 6 to 8 months was used to evaluate whether the absence of PEDF was permissive for HCC formation (n = 12/group). RESULTS: PEDF levels increased in response to canonical Wnt3a in an LRP6-dependent manner but were suppressed by noncanonical Wnt5a protein in an LRP6-independent manner. Gene set enrichment analysis (GSEA) of PEDF KO livers revealed induction of pathways associated with experimental and human HCC and a transcriptional profile characterized by Wnt/ß-catenin activation. Enhanced Wnt/ß-catenin signaling occurred in KO livers, and PEDF delivery in vivo reduced LRP6 activation. In human HCC cells, RNA interference of PEDF led to increased levels of activated LRP6 and ß-catenin, and a PEDF 34-mer peptide decreased LRP6 activation and ß-catenin signaling, and reduced Wnt target genes. PEDF KO mice fed a Western diet developed sporadic well-differentiated HCC. Human HCC specimens demonstrated decreased PEDF staining compared with hepatocytes. CONCLUSIONS: PEDF is an endogenous inhibitor of Wnt/ß-catenin signaling in the liver.

Pigment epithelium-derived factor (PEDF) suppresses IL-1ß-mediated c-Jun N-terminal kinase (JNK) activation to improve hepatocyte insulin signaling.

Pigment epithelium-derived factor (PEDF) is an antiinflammatory protein that circulates at high levels in the metabolic syndrome. Metabolic studies of PEDF knockout (KO) mice were conducted to investigate the relationship between PEDF, inflammatory markers, and metabolic homeostasis. Male PEDF KO mice demonstrated a phenotype consisting of increased adiposity, glucose intolerance, and elevated serum levels of metabolites associated with the metabolic syndrome. Genome expression analysis revealed an increase in IL-1ß signaling in the livers of PEDF KO mice that was accompanied by impaired IRS and Akt signaling. In human hepatocytes, PEDF blocked the effects of an IL-1ß challenge by suppressing activation of the inflammatory mediator c-Jun N-terminal kinase while restoring Akt signaling. RNA interference of PEDF in human hepatocytes was permissive for c-Jun N-terminal kinase activation and decreased Akt signaling. A metabolomics profile identified elevated circulating levels of tricarboxyclic acid cycle intermediates including succinate, an inducer of IL-1ß, in PEDF KO mice. Succinate-dependent IL-1ß expression was blocked by PEDF in PEDF KO, but not wild-type hepatocytes. In vivo, PEDF restoration reduced hyperglycemia and improved hepatic insulin signaling in PEDF KO mice. These findings identify elevated PEDF as a homeostatic mechanism in the human metabolic syndrome.

Sessile serrated adenomas in the proximal colon are likely to be flat, large and occur in smokers.

AIM: To examine the epidemiology and the morphology of the proximal sessile serrated adenomas (SSAs). METHODS: We conducted a retrospective study to identify patients with SSAs using a university-based hospital pathology database query from January 2007 to April 2011. Data collected included: age, gender, ethnicity, body mass index, diabetes, smoking, family history of colorectal cancer, aspirin, and statin use. We collected data on morphology of SSAs including site (proximal or distal), size, and endoscopic appearance (flat or protuberant). We also compared proximal SSAs to proximal tubular adenomas detected during same time period. RESULTS: One hundred and twenty patients with SSAs were identified: 61% were distal and 39% were proximal SSAs. Proximal SSAs were more likely to be flat than distal (100% vs 78% respectively; P = 0.0001). Proximal SSAs were more likely to occur in smokers (OR = 2.63; 95%CI: 1.17-5.90; P = 0.02) and in patients with family history of colorectal cancer (OR = 4.72; 95%CI: 1.43-15.55; P = 0.01) compared to distal. Proximal SSAs were statistically more likely to be ≥ 6 mm in size (OR = 2.94; P = 0.008), and also more likely to be large (≥ 1 cm) (OR = 4.55; P = 0.0005) compared to the distal lesions. Smokers were more likely to have proximal (P = 0.02), flat (P = 0.01) and large (P = 0.007) SSAs compared to non-smokers. Compared to proximal tubular adenomas, proximal SSAs were more likely to be large and occur in smokers. CONCLUSION: Proximal SSAs which accounted for two-fifths of all SSAs were more likely to present as flat lesions, larger SSAs, and were more likely to occur in smokers and in patients with family history of colorectal cancer. Our data has implications for colorectal cancer screening.

Brief alcohol exposure alters transcription in astrocytes via the heat shock pathway.

Astrocytes are critical for maintaining homeostasis in the central nervous system (CNS), and also participate in the genomic response of the brain to drugs of abuse, including alcohol. In this study, we investigated ethanol regulation of gene expression in astrocytes. A microarray screen revealed that a brief exposure of cortical astrocytes to ethanol increased the expression of a large number of genes. Among the alcohol-responsive genes (ARGs) are glial-specific immune response genes, as well as genes involved in the regulation of transcription, cell proliferation, and differentiation, and genes of the cytoskeleton and extracellular matrix. Genes involved in metabolism were also upregulated by alcohol exposure, including genes associated with oxidoreductase activity, insulin-like growth factor signaling, acetyl-CoA, and lipid metabolism. Previous microarray studies performed on ethanol-treated hepatocyte cultures and mouse liver tissue revealed the induction of almost identical classes of genes to those identified in our microarray experiments, suggesting that alcohol induces similar signaling mechanisms in the brain and liver. We found that acute ethanol exposure activated heat shock factor 1 (HSF1) in astrocytes, as demonstrated by the translocation of this transcription factor to the nucleus and the induction of a family of known HSF1-dependent genes, the heat shock proteins (Hsps). Transfection of a constitutively transcriptionally active Hsf1 construct into astrocytes induced many of the ARGs identified in our microarray study supporting the hypothesis that HSF1 transcriptional activity, as part of the heat shock cascade, may mediate the ethanol induction of these genes. These data indicate that acute ethanol exposure alters gene expression in astrocytes, in part via the activation of HSF1 and the heat shock cascade.

Dietary methyl donor depletion protects against intestinal tumorigenesis in Apc(Min/+) mice.

Despite recent population data, the influence of dietary folate supplementation on colon cancer risk remains controversial. This study examines the effects of folate deficiency, in combination with choline, methionine, and vitamin B12 depletion, on intestinal tumorigenesis in Apc(Min/+) mice. Methyl donor sufficient (MDS) and deficient (MDD) diets were started at five or 10 weeks of age and tumors evaluated at 16 weeks. MDD suppressed intestinal tumor formation in Apc(Min/+) mice (~80%) when started at five weeks of age. The protective effect was lost when MDD was initiated at 10 weeks of age, indicating an important time dependency on cancer suppression. Concomitant with cancer protection, MDD restricted body weight gain. Therefore, a second study was conducted in which MDS was given ad libitum or pair-fed with MDD. Although small intestinal tumors were reduced 54% in pair-fed MDS mice, MDD caused a further reduction (96%). In colon, although MDD did not affect tumor numbers, tumor size was reduced. Gene expression profiling of normal-appearing colonic mucosa after 11 weeks on MDD identified a total of 493 significantly downregulated genes relative to the MDS group. Pathway analysis placed many of these genes within general categories of inflammatory signaling and cell-cycle regulation, consistent with recently published human data obtained during folate depletion. Further studies are warranted to investigate the complex interplay of methyl donor status and cancer protection in high-risk populations.

Colonic in situ mantle cell lymphoma.

This report describes the first case, to our knowledge, of in situ mantle cell lymphoma (MCL) in the gastrointestinal tract identified retrospectively by immunostains and fluorescence in situ hybridization (FISH) analysis after progression to disseminated disease with pleomorphic morphology several years later. A 45-year-old man with blood per rectum underwent colonoscopy and had random biopsies interpreted as benign colonic mucosa. Two years later, he presented with ileocolic intussusception related to enlarged lymph nodes. Biopsies on the second presentation demonstrated widespread MCL. Reevaluation of the original colonic biopsies showed cyclin D1-positive cells within small lymphoid aggregates, confirmed by FISH for t(11;14). Postchemotherapy, lymphoid aggregates in colonic biopsies showed scattered cyclin D1- and FISH t(11;14)-positive cells, similar to the original in situ lymphoma. We discuss this case in the context of the current understanding of the evolution of MCL and the difficulties associated with detecting primary GI lymphoma.

Aberrant crypt foci as predictors of colorectal neoplasia on repeat colonoscopy.

OBJECTIVE: To estimate the risk for colorectal neoplasia detected on repeat colonoscopy in relation to aberrant crypt foci (ACF) frequency reported during the previous baseline examination. METHODS: From July 2003 until December 2008, patients had a colonoscopy with an ACF study using a magnifying colonoscope. The distal 20 cm section of colon was sprayed with Methylene Blue to ascertain the ACF frequency, the independent variable. Patients were categorized into low and high ACF count using the median as the cut point. Data collected from consenting patients included age, gender, height, weight, ethnicity, smoking history, family history of colorectal cancer (CRC), and personal history of colorectal neoplasia. A follow-up colonoscopy was performed at an interval as dictated by clinical surveillance guidelines. The main outcome was surveillance detected advanced colorectal neoplasia (SDAN) detected on repeat colonoscopy. Logistic Regression was used to calculate risk of SDAN on repeat colonoscopy in relation to baseline ACF count. RESULTS: 74 patients had a baseline ACF exam and a repeat surveillance colonoscopy. The median ACF was six and thus a high ACF count was >6 ACF and a low ACF count was ≤6 ACF. Patients diagnosed with SDAN were more likely to have had a high ACF number at baseline compared to patients without these lesions at follow-up (adjusted odds ratio = 12.27; 95% confidence interval: 2.00-75.25) controlling for age, sex, smoking, history of prior adenoma, family history of colon cancer, obesity, and time interval to surveillance exam. A sub analysis of our results demonstrated that this relationship was observed in 48 patients who were undergoing a surveillance colonoscopy for a previous adenoma and not those receiving surveillance for a family history of neoplasia. CONCLUSIONS: Increased number of ACF in the distal colorectum was independently associated with substantial risk for future advanced neoplasia. This relationship was observed in patients undergoing surveillance for previous adenomas. Thus, ACF may serve as potential biomarkers in patients with adenomas to help identify patients who may need additional surveillance.

Pigment epithelium-derived factor regulates early pancreatic fibrotic responses and suppresses the profibrotic cytokine thrombospondin-1.

Pigment epithelium-derived factor (PEDF) is important for maintaining the normal extracellular matrix. We hypothesized that the initiation of pancreatic fibrosis is dependent on the loss of PEDF. Pancreatic PEDF expression was assessed in wild-type mice fed either a control or ethanol diet using an intragastric feeding model. Pancreatitis responses were elicited with either a single episode or a repetitive cerulein-induced (50 µg/kg, 6 hourly i.p. injections) protocol in wild-type and PEDF-null mice. Quantitative real-time PCR and immunoblotting were performed to assess fibrogenic responses. In wild-type animals, PEDF expression increased with pancreatitis and was more pronounced in mice fed ethanol. Compared with wild-type mice, α-smooth muscle actin staining and expression levels of fibrogenic markers (eg, transforming growth factor-ß1, platelet-derived growth factor, collagen I, and thrombospondin-1) were higher in PEDF-null mice at baseline. Sirius red staining revealed more fibrosis in PEDF-null versus wild-type pancreas 1 week after pancreatitis. Differences in tissue fibrosis resolved with longer recovery periods. PEDF overexpression suppressed thrombospondin-1 levels in vitro. Ethanol feeding and experimental pancreatitis increased PEDF expression in wild-type mice. PEDF-null mice, however, demonstrated enhanced early fibrotic responses compared with wild-type mice with pancreatitis. These findings indicate that PEDF acts as a compensatory antifibrotic cytokine in pancreatitis.

Acute hepatitis E infection accounts for some cases of suspected drug-induced liver injury.

BACKGROUND & AIMS: The diagnosis of drug-induced liver injury relies on exclusion of other causes, including viral hepatitis A, B, and C. Hepatitis E virus (HEV) infection has been proposed as another cause of suspected drug-induced liver disease. We assessed the frequency of HEV infection among patients with drug-induced liver injury in the United States. METHODS: The Drug-Induced Liver Injury Network (DILIN) is a prospective study of patients with suspected drug-induced liver injury; clinical information and biological samples are collected to investigate pathogenesis and disease progression. We analyzed serum samples, collected from patients enrolled in DILIN, for immunoglobulin (Ig) G and IgM against HEV; selected samples were tested for HEV RNA. RESULTS: Among 318 patients with suspected drug-induced liver injury, 50 (16%) tested positive for anti-HEV IgG and 9 (3%) for anti-HEV IgM. The samples that contained anti-HEV IgM (collected 2 to 24 weeks after onset of symptoms) included 4 that tested positive for HEV RNA genotype 3. Samples from the 6-month follow-up visit were available from 4 patients; they were negative for anti-HEV IgM, but levels of anti-HEV IgG increased with time. Patients who had anti-HEV IgM were mostly older men (89%; mean age, 67 years), and 2 were human immunodeficiency virus positive. Clinical reassessment of the 9 patients with anti-HEV IgM indicated that acute hepatitis E was the most likely diagnosis for 7 and might be the primary diagnosis for 2. CONCLUSIONS: HEV infection contributes to a small but important proportion of cases of acute liver injury that are suspected to be drug induced. Serologic testing for HEV infection should be performed, particularly if clinical features are compatible with acute viral hepatitis.

Altered folate availability modifies the molecular environment of the human colorectum: implications for colorectal carcinogenesis.

Low folate status increases colorectal cancer risk. Paradoxically, overly abundant folate supplementation, which is not uncommon in the United States, may increase risk. The mechanisms of these effects are unknown. We conducted two translational studies to define molecular pathways in the human colon altered either by folate supplementation or by dietary folate depletion (followed by repletion). In the first study, 10 healthy, at-risk volunteers (with documented stable/normal folate intake) received supplemental folic acid (1 mg/d) for 8 weeks. In the second study, 10 similar subjects were admitted to a hospital as inpatients for 12 weeks to study folate depletion induced by a low folate diet. A repletion regimen of folic acid (1 mg/d) was provided for the last 4 of these weeks. Both studies included an 8-week run-in period to ensure stabilized folate levels prior to intervention. We obtained 12 rectosigmoid biopsies (from 4 quadrants of normal-appearing mucosa 10-15 cm from the anal verge) at baseline and at measured intervals in both studies for assessing the primary endpoints: genome-wide gene expression, genomic DNA methylation, promoter methylation (depletion/repletion study only), and p53 DNA strand breaks. Serum and rectosigmoid folate concentrations accurately tracked all changes in folate delivery (P < 0.05). In the first study, gene array analysis revealed that supplementation upregulated multiple inflammation- and immune-related pathways in addition to altering several 1-carbon-related enzymes (P < 0.001). In the second study, folate depletion downregulated genes involved in immune response, inflammation, the cell cycle, and mitochondrial/energy pathways; repletion reversed most of these changes. However, changes in gene expression after repletion in the second study (involving immune response and inflammation) did not reach the levels seen after supplementation in the first study. Neither genomic nor promoter-specific DNA methylation changed during the course of the depletion/repletion protocol, and genomic methylation did not change with supplementation in the first study. p53 DNA strand breaks increased with depletion after 12 weeks. In sum, depletion downregulates, whereas repletion or supplementation upregulates pathways related to inflammation and immune response. These findings provide novel support to the concept that excessive folate supplementation might promote colorectal carcinogenesis by enhancing proinflammatory and immune response pathways. These results indicate that modest changes in folate delivery create substantial changes in the molecular milieu of the human colon.

Risk factors for sessile serrated adenomas.

BACKGROUND: Although sessile serrated adenomas (SSAs) may represent a separate and important pathway for colorectal cancer (CRC), little is known about the risk factors for these lesions. Molecular abnormalities such as BRAF have been observed in SSA and smokers. Our hypothesis is that smoking may be associated with these lesions. METHODS: All patients diagnosed with an SSA from January 2007 to September 2010 were identified retrospectively based on a pathology database query. There were 2 sets of controls. One group had no adenomas, whereas another group had tubular adenomas. These groups were randomly identified from 2007 to 2010. Data collected included age, sex, ethnicity, height, weight, family history of CRC, diabetes mellitus, use of aspirin, statins, and calcium, and serum trigylcerides and cholesterol. We defined smokers as those patients who smoked at least 20 pack-years. RESULTS: We identified 90 patients with an SSA of any size, 90 patients with tubular adenomas, and 200 controls with no adenomas. Of the 90 SSAs, 42 were 6 mm or larger and 19 of them were ≥1 cm. Most of the SSAs was flat (76/90; 84.4%). After multivariate analyses, smokers with at least 20 pack-year exposure were found to have an increased risk [adjusted odds ratio (OR)=7.31; 95% confidence interval (CI), 3.92-13.63] of having any SSAs, SSAs ≥6 mm (adjusted OR=7.77; 95% CI, 3.48-17.35), and large SSAs (adjusted OR=10.20; 95% CI, 3.31-31.41) compared with nonsmokers. We also observed this relationship when comparing patients with SSAs to those with tubular adenomas. CONCLUSIONS: Our data suggest that smoking at least 20 pack-years is strongly associated with any and large SSAs. In addition, diabetes mellitus and obesity seem to be associated with SSAs as well. Our data has implications for CRC screening.

Increased frequency of serrated aberrant crypt foci among smokers.

OBJECTIVES: The American College of Gastroenterology has published guidelines recently that suggest that smokers with a history of >20 pack years may need screening for colorectal cancer (CRC) at an earlier age than non-smokers. Aberrant crypt foci (ACF) may represent important precursors for colorectal neoplasms and potential surrogate biomarkers. Clarifying the role of ACF in relation to known CRC risk factors such as smoking may have important implications for screening as well as our understanding of tobacco use and colorectal carcinogenesis. Our goal was to examine whether smoking at least 20 pack years was associated with an increased frequency of ACF. METHODS: We gathered detailed smoking history, personal and family history of CRC, and other epidemiologic data (age, gender, height, weight, ethnicity, and medication use) from 125 patients undergoing routine screening or surveillance colonoscopy. We used a magnifying colonoscope (Olympus Close Focus Colonoscope XCF-Q160ALE, Olympus Corporation, Tokyo, Japan) and examined the distal 20 cm section of colon after staining with 0.5% methylene blue. ACF were counted and characterized histologically. Hyperplastic ACF were further characterized as either serrated or non-serrated. RESULTS: Smoking at least 20 pack years was associated with an increased likelihood (adjusted odds ratio (OR)=3.45; 95% confidence interval (CI)=1.93-6.18) of having more than the median number of ACF (> or = 15) compared with non-smokers. Similarly, patients with a personal history of advanced neoplasia were more likely (adjusted OR=3.42; 95% CI=1.01-11.67) to have a greater than median number of ACF compared with patients without this diagnosis. Smokers were more likely than non-smokers to have serrated ACF (P=0.002). CONCLUSIONS: Smoking at least 20 pack years seems to be associated with increased number of ACF in the rectum and distal sigmoid, especially those with serrated histology. Our data support ACG guidelines for earlier screening for CRC among smokers and add to our understanding of how colorectal carcinogenesis is related to tobacco use.