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Background: High numbers of lymphocytes in tumor tissue, including T regulatory cells (Treg), have been associated with better colorectal cancer survival. Tregs, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and therefore variants in genes related to Treg differentiation and function could be associated with colorectal cancer prognosis. Methods: In a prospective German cohort of 3,593 colorectal cancer patients, we assessed the association of 771 single-nucleotide polymorphisms (SNP) in 58 Treg-related genes with overall and colorectal cancer–specific survival using Cox regression models. Effect modification by microsatellite instability (MSI) status was also investigated because tumors with MSI show greater lymphocytic infiltration and have been associated with better prognosis. Replication of significant results was attempted in 2,047 colorectal cancer patients of the International Survival Analysis in Colorectal Cancer Consortium (ISACC). Results: A significant association of the TGFBR3 SNP rs7524066 with more favorable colorectal cancer–specific survival [hazard ratio (HR) per minor allele: 0.83; 95% confidence interval (CI), 0.74–0.94; P value: 0.0033] was replicated in ISACC (HR: 0.82; 95% CI, 0.68–0.98; P value: 0.03). Suggestive evidence for association was found with two IL7 SNPs, rs16906568 and rs7845577. Thirteen SNPs with differential associations with overall survival according to MSI in the discovery analysis were not confirmed. Conclusions: Common genetic variation in the Treg pathway implicating genes such as TGFBR3 and IL7 was shown to be associated with prognosis of colorectal cancer patients. Impact: The implicated genes warrant further investigation.

Verrucous esophageal carcinoma (VEC) is a rare malignancy that presents a diagnostic challenge. We aim to characterize the clinical and genomic features, tumor behavior, and treatment outcomes of VEC to guide clinical practice. We performed a systematic review of the literature and identified additional cases from Massachusetts General Hospital records and The Cancer Genome Atlas (TCGA). We obtained individual VEC patient data and analyzed publicly available clinicogenomic data from TCGA. We performed a regression analysis comparing cases of VEC to esophageal squamous cell carcinoma (ESCC) to identify factors influencing survival. A total of 135 patients were reported in 82 publications, and four unpublished cases from Massachusetts General Hospital (median age 65 years, 69% males, 48% smokers, 33% consumed alcohol). Symptoms were present at diagnosis in 95% of patients, most commonly dysphagia and weight loss. Median symptom onset to diagnosis time was 11.5 months with frequent misdiagnosis as Candida esophagitis. Among VEC cases with pathologic staging, lymph node metastases were rare (5%) compared to ESCC (40%). VEC was genomically characterized by enrichment of SMARCA4 missense mutations and a lack of pathogenic TP53 mutations. Despite its diagnostic elusiveness, in a multivariate regression analysis, VEC was detected at earlier stages (p =

Low-dose aspirin is recommended by the U.S. Preventive Services Task Force for primary prevention of colorectal cancer in certain individuals. However, broader implementation will require improved precision prevention approaches to identify those most likely to benefit. The major urinary metabolite of PGE2, 11α-hydroxy-9,15-dioxo-2,3,4,5-tetranor-prostane-1,20-dioic acid (PGE-M), is a biomarker for colorectal cancer risk, but it is unknown whether PGE-M is modifiable by aspirin in individuals at risk for colorectal cancer. Adults (N = 180) who recently underwent adenoma resection and did not regularly use aspirin or NSAIDs were recruited to a double-blind, placebo-controlled, randomized trial of aspirin at 81 or 325 mg/day for 8–12 weeks. The primary outcome was postintervention change in urinary PGE-M as measured by LC/MS. A total of 169 participants provided paired urine samples for analysis. Baseline PGE-M excretion was 15.9 ± 14.6 (mean ± S.D, ng/mg creatinine). Aspirin significantly reduced PGE-M excretion (−4.7 ± 14.8) compared with no decrease (0.8 ± 11.8) in the placebo group (P = 0.015; mean duration of treatment = 68.9 days). Aspirin significantly reduced PGE-M levels in participants receiving either 81 (−15%; P = 0.018) or 325 mg/day (−28%; P < 0.0001) compared with placebo. In 40% and 50% of the individuals randomized to 81 or 325 mg/day aspirin, respectively, PGE-M reduction reached a threshold expected to prevent recurrence in 10% of individuals. These results support that aspirin significantly reduces elevated levels of PGE-M in those at increased colorectal cancer risk to levels consistent with lower risk for recurrent neoplasia and underscore the potential utility of PGE-M as a precision chemoprevention biomarker. The ASPIRED trial is registered as NCT02394769.

Background Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown. Methods Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis. Results During 18–20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (Pheterogeneity=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584). Conclusions Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC.

Implementation of polygenic risk scores (PRS) may improve disease prevention and management but requires the construction and validation of clinical assays, interpretation, and reporting pipelines. We developed a clinical genotype array-based assay for published PRS for 6 common diseases. First, we calculated PRS for 36,423 Mass General Brigham Biobank (MGBB) participants. Finding significant variation in the PRS distributions by race, we implemented adjustment for population structure with ancestry-informative principal components. We replicated published thresholds for odds ratio (OR)>2 in MGBB overall [ranging from 1.75 (1.57, 1.95) for Type 2 diabetes to 2.38 (2.07, 2.73) for breast cancer]. After confirming the high performance and robustness of the pipeline for use as a clinical assay, we analyzed the first 141 prospective samples from the Genomic Medicine at VA Study; frequency of PRS corresponding to published OR>2 ranged from 5/141 (3.6%) for colorectal cancer to 8/48 (16.7%) for breast cancer. Our development of a clinical PRS assay for multiple conditions illustrates the generalizability of this process and necessary technical and reporting decisions for meaningful clinical PRS implementation.

N95 filtering facepiece respirators (FFR) and surgical masks are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. However, currently available FFR's and masks have major limitations, including masking facial features, waste, and integrity after decontamination. In a multi-institutional trial, we evaluated a transparent, elastomeric, adaptable, long-lasting (TEAL) respirator to evaluate success of qualitative fit test with user experience and biometric evaluation of temperature, respiratory rate, and fit of respirator using a novel sensor. There was a 100% successful fit test among participants, with feedback demonstrating excellent or good fit (90% of participants), breathability (77.5%), and filter exchange (95%). Biometric testing demonstrated significant differences between exhalation and inhalation pressures among a poorly fitting respirator, well-fitting respirator, and the occlusion of one filter of the respirator. We have designed and evaluated a transparent elastomeric respirator and a novel biometric feedback system that could be implemented in the hospital setting., NIH(Grants K23DA044874, R44DA051106), NIH (Grants K23DA044874, R44DA051106, 5T32DK007191-4)

INTRODUCTION: Somatic mutations in BRCA1/2 and other homologous recombination repair (HRR) genes have been associated with sensitivity to PARP inhibitors and/or platinum agents in several cancers, whereas hypermutant tumors caused by alterations in POLE or mismatch repair genes have demonstrated robust responses to immunotherapy. We investigated the relationship between somatic truncations in HRR genes and hypermutation in colorectal cancer (CRC) and endometrial cancer (EC). METHODS: We analyzed the mutational spectra associated with somatic BRCA1/2 truncations in multiple genomic cohorts (N = 2,335). From these results, we devised a classifier incorporating HRR genes to predict hypermutator status among microsatellite stable (MSS) tumors. Using additional genomic cohorts (N = 1,439) and functional in vivo assays, we tested the classifier to disambiguate POLE variants of unknown significance and identify MSS hypermutators without somatic POLE exonuclease domain mutations. RESULTS: Hypermutator phenotypes were prevalent among CRCs with somatic BRCA1/2 truncations (50/62, 80.6%) and ECs with such mutations (44/47, 93.6%). The classifier predicted MSS hypermutators with a cumulative true-positive rate of 100% in CRC and 98.0% in EC and a false-positive rate of 0.07% and 0.63%. Validated by signature analyses of tumor exomes and in vivo assays, the classifier accurately reassigned multiple POLE variants of unknown significance as pathogenic and identified MSS hypermutant samples without POLE exonuclease domain mutations. DISCUSSION: Somatic truncations in HRR can accurately fingerprint MSS hypermutators with or without known pathogenic exonuclease domain mutations in POLE and may serve as a low-cost biomarker for immunotherapy decisions in MSS CRC and EC.

Emerging data highlight the critical role for the innate immune system in the progression of nonalcoholic fatty liver disease (NAFLD). Connexin 32 (Cx32), the primary liver gap junction protein, is capable of modulating hepatic innate immune responses and has been studied in dietary animal models of steatohepatitis. In this work, we sought to determine the association of hepatic Cx32 with the stages of human NAFLD in a histologically characterized cohort of 362 patients with NAFLD. We also studied the hepatic expression of the genes and proteins known to interact with Cx32 (known as the connexome) in patients with NAFLD. Last, we used three independent dietary mouse models of nonalcoholic steatohepatitis to investigate the role of Cx32 in the development of steatohepatitis and fibrosis. In a univariate analysis, we found that Cx32 hepatic expression associates with each component of the NAFLD activity score and fibrosis severity. Multivariate analysis revealed that Cx32 expression most closely associated with the NAFLD activity score and fibrosis compared to known risk factors for the disease. Furthermore, by analyzing the connexome, we identified novel genes related to Cx32 that associate with NAFLD progression. Finally, we demonstrated that Cx32 deficiency protects against liver injury, inflammation, and fibrosis in three murine models of nonalcoholic steatohepatitis by limiting initial diet-induced hepatoxicity and subsequent increases in intestinal permeability. Conclusion: Hepatic expression of Cx32 strongly associates with steatohepatitis and fibrosis in patients with NAFLD. We also identify novel genes associated with NAFLD and suggest that Cx32 plays a role in promoting NAFLD development. (Hepatology Communications 2018;2:786-797).

BACKGROUND: While monoclonal antibodies against tumor necrosis factor-α (TNFα) are effective in treating Crohn’s disease (CD), approximately one-third of patients lose response. The mechanisms underlying this loss of response remain elusive. AIM: We sought to determine if novel biological pathways, including TNFα-independent inflammatory pathways, emerge in those with loss of response to anti-TNFα. METHODS: Using RNA microarray technology in 28 patients with CD, we examined the colonic gene expression differences between those with active inflammation in the setting of loss of response to TNFα-antagonist therapy (“loss of responders”) compared to anti-TNFα naïve patients with active inflammation and those on anti-TNF therapy in disease remission. Pathway enrichment analyses were performed. RESULTS: We found that colonic expression of chemokines known to drive inflammation (CXCL20, CXCL9, and CXCL10) were elevated in those with loss of response compared to those in remission. Expression of genes critical to modulating oxidative stress burden (DUOX2, DUOXA2, and NOS2) were also elevated. Additionally, MMP3, MMP1, and MMP12 were elevated in those with continued inflammation. Gene enrichment analysis revealed that loss of responders exhibited dysregulation in the cysteine and methionine metabolism pathway, suggesting alteration in oxidative stress burden. There were no differences in genes or pathways between loss of responders and those who were TNFα-naïve. However, loss of response occurred despite the ability of anti-TNFα therapy to normalize APO gene expression. CONCLUSION: Our analyses suggest that loss of response to anti-TNFα is not driven by the emergence of pathways that bypass the action or induce resistance to anti-TNFα therapy.

INTRODUCTION: The expression of LGR5, a known stem cell marker, is poorly understood in Barrett's esophagus (BE) and related neoplasia. The aim of this study was to evaluate LGR5 in BE and related neoplasia and to evaluate its utility as a potential biomarker of progression to advanced neoplasia. METHODS: We evaluated total 137 patients, including 119 with BE and 18 with normal gastroesophageal mucosa for expression of LGR5 using RNA in situ hybridization; this also included 28 progressors and 30 nonprogressors. The LGR5 stain was evaluated using 1 qualitative and 2 quantitative parameters, using manual and automated platforms. RESULTS: Surface LGR5 expression was mainly seen in high-grade dysplasia (12/18) compared with low-grade dysplasia (1/8) and nondysplastic BE (0/17) (P < 0.0001). In contrast to nondysplastic BE, low- and high-grade dysplasia showed a higher percentage of mean number of LGR5-positive crypts per patient (P < 0.0001) and an increase in the mean number of LGR5 transcripts per cell (P < 0.0001). The mean percentage of LGR5-positive crypts per patient and the mean number of LGR5 transcripts per cell were also significantly higher in nondysplastic BE from progressor compared with nonprogressor (P < 0.0001, P = 0.014). The sensitivity and specificity of LGR5 for distinguishing progressor from nonprogressor were 50% and 87%, respectively. DISCUSSION: BE-related advanced neoplasia shows an expansion of the LGR5-positive cellular compartment, supporting its role as a stem cell marker in this disease. Quantitative LGR5 expression and surface epithelial reactivity are novel biomarkers of increased risk of progression to advanced neoplasia in BE.

Significance Alcohol-related liver disease is a leading cause of mortality worldwide. Improved patient outcomes will be driven by advances in our understanding of disease pathogenesis, allowing for the development of novel, targeted therapeutics. By combining patient data with animal models of alcohol-related liver disease, we demonstrate the critical importance of the cyclic guanosine monophosphate–adenosine monophosphate synthase-interferon regulatory factor 3 (cGAS-IRF3) pathway and its amplification through hepatocyte intercellular communication in fueling liver injury caused by alcohol. Thus, our results identify two potentially druggable pathways to improve patient outcomes and reduce mortality resulting from this devastating disease., Alcohol-related liver disease (ALD) accounts for the majority of cirrhosis and liver-related deaths worldwide. Activation of IFN-regulatory factor (IRF3) initiates alcohol-induced hepatocyte apoptosis, which fuels a robust secondary inflammatory response that drives ALD. The dominant molecular mechanism by which alcohol activates IRF3 and the pathways that amplify inflammatory signals in ALD remains unknown. Here we show that cytoplasmic sensor cyclic guanosine monophosphate-adenosine monophosphate (AMP) synthase (cGAS) drives IRF3 activation in both alcohol-injured hepatocytes and the neighboring parenchyma via a gap junction intercellular communication pathway. Hepatic RNA-seq analysis of patients with a wide spectrum of ALD revealed that expression of the cGAS-IRF3 pathway correlated positively with disease severity. Alcohol-fed mice demonstrated increased hepatic expression of the cGAS-IRF3 pathway. Mice genetically deficient in cGAS and IRF3 were protected against ALD. Ablation of cGAS in hepatocytes only phenocopied this hepatoprotection, highlighting the critical role of hepatocytes in fueling the cGAS-IRF3 response to alcohol. We identified connexin 32 (Cx32), the predominant hepatic gap junction, as a critical regulator of spreading cGAS-driven IRF3 activation through the liver parenchyma. Disruption of Cx32 in ALD impaired IRF3-stimulated gene expression, resulting in decreased hepatic injury despite an increase in hepatic steatosis. Taken together, these results identify cGAS and Cx32 as key factors in ALD pathogenesis and as potential therapeutic targets for hepatoprotection.

Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p-value = 3.5 × 10-6 ) and rs2189517 (in RAD51B) with rectal cancer risk (p-value = 5.7 × 10-6 ). The results had statistical significance close to the Bonferroni corrected p-value of 5.8 × 10-6 . Ninety-four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis-eQTL suggesting possible mechanisms of carcinogenesis.

The anti-inflammatory properties of aspirin have resulted in its widespread use as an analgesic, antipyretic, and cardioprotective agent. Beyond these applications, multiple observational studies and randomized controlled trials have demonstrated a chemopreventative role for aspirin, particularly in the development of colorectal neoplasia. Given the critical importance of Wnt dysregulation in colorectal carcinogenesis, the interplay between aspirin and canonical Wnt signaling has become a focus of investigation. These studies have illuminated our understanding of the anticancer mechanisms of aspirin, yielding the identification of potential biomarkers for which aspirin's chemopreventative efficacy can be safely optimized into routine clinical practice and providing leads into the discovery of novel preventive and therapeutic targets. In this review, we summarize key experimental and clinical studies of this interaction, as well as highlighting future strategies to advance their clinical translation. Clin Cancer Res; 21(7); 1543–8. ©2014 AACR.

BACKGROUND: Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown. METHODS: Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis. RESULTS: During 18–20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (P(heterogeneity)=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584). CONCLUSIONS: Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC.

Background Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties. Methods/design ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function. Discussion Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers. Trial registration This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769. Registered on 16 March 2015. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1744-z) contains supplementary material, which is available to authorized users.

A 59-year-old man was admitted to the hospital because of 9 months of abdominal pain, vomiting, and weight loss. He was born in a Caribbean country and had been treated for intestinal strongyloidiasis years earlier. A diagnosis of celiac disease had recently been made elsewhere.

Next-generation sequencing has evolved technically and economically into the method of choice for interrogating the genome in cancer and inherited disorders. The introduction of procedural code sets for whole-exome and genome sequencing is a milestone toward financially sustainable clinical implementation; however, achieving reimbursement is currently a major challenge. As part of a prospective quality-improvement initiative to implement the new code sets, we adopted Agile, a development methodology originally devised in software development. We implemented eight functionally distinct modules (request review, cost estimation, preauthorization, accessioning, prebilling, testing, reporting, and reimbursement consultation) and obtained feedback via an anonymous survey. We managed 50 clinical requests (January to June 2015). The fraction of pursued-to-requested cases (n = 15/50; utilization management fraction, 0.3) aimed for a high rate of preauthorizations. In 13 of 15 patients the insurance plan required preauthorization, which we obtained in 70% and ultimately achieved reimbursement in 50%. Interoperability enabled assessment of 12 different combinations of modules that underline the importance of an adaptive workflow and policy tailoring to achieve higher yields of reimbursement. The survey confirmed a positive attitude toward self-organizing teams. We acknowledge the individuals and their interactions and termed the infrastructure: human pipeline. Nontechnical barriers currently are limiting the scope and availability of clinical genomic sequencing. The presented human pipeline is one approach toward long-term financial sustainability of clinical genomics.

Genome-wide association studies have identified several germline single nucleotide polymorphisms (SNPs) significantly associated with colorectal cancer (CRC) incidence. Common germline genetic variation may also be related to CRC survival. We used a discovery-based approach to identify SNPs related to survival outcomes after CRC diagnosis. Genome-wide genotyping arrays were conducted for 3494 individuals with invasive CRC enrolled in six prospective cohort studies (median study-specific follow-up = 4.2-8.1 years). In pooled analyses, we used Cox regression to assess SNP-specific associations with CRC-specific and overall survival, with additional analyses stratified by stage at diagnosis. Top findings were followed-up in independent studies. A P value threshold of P < 5×10(-8) in analyses combining discovery and follow-up studies was required for genome-wide significance. Among individuals with distant-metastatic CRC, several SNPs at 6p12.1, nearest the ELOVL5 gene, were statistically significantly associated with poorer survival, with the strongest associations noted for rs209489 [hazard ratio (HR) = 1.8, P = 7.6×10(-10) and HR = 1.8, P = 3.7×10(-9) for CRC-specific and overall survival, respectively). No SNPs were statistically significantly associated with survival among all cases combined or in cases without distant-metastases. SNPs in 6p12.1/ELOVL5 were associated with survival outcomes in individuals with distant-metastatic CRC, and merit further follow-up for functional significance. Findings from this genome-wide association study highlight the potential importance of genetic variation in CRC prognosis and provide clues to genomic regions of potential interest.

The genetic contribution to the development of colon cancer has been inferred to be approximately 35 % from large Scandinavian twin registries. Independent studies indicate that 11–16 % of those with a diagnosis of colon cancer also have a first-degree relative with colon cancer. A significant fraction of these familial cases are represented by well-characterized, high-risk familial cancer syndromes that display Mendelian or near-Mendelian patterns of inheritance. Accounting for nearly 5 % of all colon cancer cases, these disorders are also associated with a diverse array of extracolonic malignancies. Careful integration of clinical features, family history, endoscopic findings, molecular pathology, and genetic testing are crucial components in establishing the diagnosis of a hereditary cancer syndrome. Recognition and diagnosis of these syndromes enable healthcare providers to pursue cancer risk-reducing measures, including chemoprevention, heightened surveillance, and prophylactic surgery, for these patients and affected family members. In addition, awareness of such syndromes has important ramifications for cancer management.

Endoscopic ampullectomy is increasingly performed in patients with familial adenomatous polyposis (FAP)-associated ampullary adenomas. We sought to define the procedure-associated morbidities and long-term outcomes. We performed a retrospective chart review of patients with FAP who underwent endoscopic ampullectomy at two tertiary institutions between 1999 and 2010. The severity of duodenal polyposis was classified according to Spigelman’s classification. Of 26 FAP patients who underwent endoscopic ampullectomy, 21 arose in the setting of Spigelman’s stage II duodenal polyposis. Adverse events associated with endoscopic ampullectomy included acute pancreatitis (19.2 %), abdominal pain (7.6 %), and bleeding (3.8 %). The mean resected adenoma size was 0.99 ± 0.34 cm. Three adenomas (12.0 %) contained foci of high-grade dysplasia. Follow-up data were available for 24 patients. The mean follow-up duration was 84.5 ± 36.2 months. Adenoma recurrence was observed in 14 patients (58.3 %; 14/24) at a mean of 38.3 months after initial ampullectomy. Adenomas ≥10 mm recurred more frequently than smaller adenomas (76.9 vs. 36.4 %; p = 0.002). Positive margins were not associated with higher recurrence rates. No cancers were observed during long-term follow-up. Three patients underwent a Whipple procedure, but none was performed for a recurrent ampullary adenoma. Endoscopic ampullectomy in FAP can be performed safely. Because ampullary adenomas frequently recur after endoscopic ampullectomy, close surveillance is essential. Smaller tumors are less likely to recur, suggesting a benefit for early recognition of these lesions.

Objectives: Obesity is an important risk factor for the development of colorectal cancer (CRC). Although the impact of bariatric surgery on CRC is conflicting, its impact on precursor lesions is unknown. The aim of this study was to determine whether bariatric surgery before index screening colonoscopy is associated with decreased development of colorectal adenomas. Methods: We performed a retrospective cohort study of bariatric surgery patients who had undergone index, screening colonoscopy at an academic center from 2001 to 2014. Patients who had bariatric surgery at least 1 year before index colonoscopy were compared with those who had surgery after colonoscopy, using multivariable logistic regression to control for presurgical body mass index, sex, gender, race, type of surgery, aspirin use, metformin use, smoking, and age at colonoscopy. Results: One hundred and twenty-five obese individuals who had bariatric surgery before colonoscopy were compared with 223 individuals who had colonoscopy after surgery. Adenomatous polyps were found in 16.8% of individuals who had surgery first vs. 35.5% who had colonoscopy before bariatric surgery (unadjusted odds ratio (OR) 0.37, 95% confidence interval (CI): 0.21-0.64, P=0.0003). After multivariable adjustment, bariatric surgery before index screening colonoscopy was associated with a decreased risk of adenomas at index colonoscopy (adjusted OR 0.37, 95% CI: 0.19-0.69, P=0.002). Conclusions: Bariatric surgery is associated with a decreased risk of colorectal adenomas in obese individuals without a family history of CRC., National Institutes of Health (U.S.) (Grant T32-DK007191)

Colon cancer is associated with a family history in up to 25% of cases. As many as 5% are associated with an established hereditary syndrome, demonstrating the profound influence of inheritable genetic mechanisms in the development of this disease. These syndromes confer a diverse spectrum of risk, age of presentation, endoscopic and histological findings, extracolonic manifestations, and modes of inheritance. As the molecular characteristics of these disorders become better described, enhanced genotype-phenotype correlations may offer a more targeted approach to diagnosis, screening, and surveillance. While the strategies for diagnosis and management of familial adenomatous polyposis (FAP) and Lynch syndrome are more established, the approach to newly recognized syndromes such as MUTYH-associated polyposis (MAP) and hyperplastic polyposis syndromes continues to evolve. Effective cancer prevention in affected individuals and at-risk family members first requires timely recognition of these hereditary colon cancer syndromes followed by integration of genetic testing and clinical examinations.

Accounting for ~15% of all colorectal cancers (CRCs), the serrated pathway represents an alternate mechanism of colorectal carcinogenesis that yields microsatellite stable (MSS) tumors and the overwhelming fraction of “sporadic” microsatellite instability high (MSI-H) tumors. Moreover, the MSI-H tumors derived from the serrated pathway are more common of the two, and frequently display excessive CpG island promoter hypermethylation (CIMP-high; Table 1). This promoter hypermethylation results in epigenetic silencing of a large number of tumor-suppressor genes, including MLH1, which causes the associated MSI-H phenotype. Somatic mutations typically include activating mutations in BRAF (V600E), and less commonly KRAS or aberrant EGFR activation, which occur during the early stages of serrated polyp development. In contrast to tubular adenomas, bilallelic inactivation of APC is not an initiating event in this pathway (Figure 1). Despite this molecular understanding and the development of novel drugs to target them, additional treatments are still needed given the inferior outcomes observed in BRAF-mutated colon cancers within the context of their microsatellite status.1 Figure 1 Serrated Pathway to Colorectal Cancer. Schematic comparing the mutational changes involved from normal mucosa to colorectal cancer. The top half represents the conventional pathway to colorectal cancer, with the most frequent mutational events described. ... Table 1 Important acronyms and definitions Discovery of high-risk genetic variants for this pathway represents a promising strategy to identify additional therapeutic targets for this subset of colorectal cancers. Epidemiologic data from families of serrated polyposis patients strongly suggest a heritable predisposition exists toward serrated colorectal carcinogenesis. First-degree relatives of serrated polyposis patients are at significantly higher elevated risk of developing serrated polyps themselves. In addition, elevated pleiotropic cancer risks are present in these families. An Australian cohort demonstrated that relatives are at an increased risk of pancreatic cancer.2 First-degree relatives of those with MSI-H CRC who do not have Lynch syndrome or serrated polyposis are at increased risk (standardized incidence ratios) of developing stomach, ovarian, and liver cancers.3 Through exome sequencing of individuals who develop multiple sessile serrated polyps and/or serrated polyposis, we recently identified novel high-risk variants for the serrated pathway.4 We demonstrated that such individuals are approximately fourfold enriched for rare, germline loss-of-function (LoF) mutations (defined as nonsense and splice-site mutations) in genes responsible for oncogene-induced senescence (OIS) mechanisms. OIS is a tumor-suppressive mechanism that is activated by the replicative and metabolic stress caused by oncogenic transformation. This hypothesis was based on the observations from genetic mouse models of serrated neoplasia in which the BRAF V600E mutation or activating KRAS mutation was alone sufficient to induce serrated neoplasia in the long-term; however, in the short-term, OIS barriers prevented rapid tumorigenesis.5, 6, 7 Concurrent inactivation of these OIS mechanisms with activating BRAF/KRAS mutations greatly expedited serrated neoplasia formation. In humans, activation of these critical OIS pathways (ATM–ATR DNA damage pathway and p16-RB pathway) has been previously demonstrated to be relevant in colonic precursor lesions in addition to lesions in other tissue types. Several of the OIS genes identified in serrated polyposis patients in this study (ATM, RBL1, and XAF1) have been previously implicated in human or animal studies of colorectal carcinogenesis. We next demonstrated that the remaining patients with serrated polyposis (who do not have an obvious loss-of-function mutation) actually harbor deleterious variants in genes previously unassociated, but critical to these OIS mechanisms. Cross-referencing all rare LoF mutations found in patients with an orthogonal database (not dependent on senescence characteristics) of all genes implicated in cancer by genome-wide association studies, we discovered two unrelated individuals with identical nonsense mutations in RNF43, a gene frequently mutated in mucinous neoplasms of the pancreas and stomach that encodes for a negative regulator of Wnt signaling through Wnt receptor endocytosis. This enrichment in cases of serrated polyposis was significant over controls with sizeable effect sizes (odds ratio 460, P=6.8 × 10−5). Analysis of publicly available microarrays of sporadic serrated polyps and tubular adenomas, we found RNF43 to be significantly downregulated in the serrated pathway. Through functional experiments in pancreatic duct cells harboring the KRAS G12D oncogene, we demonstrated that silencing of RNF43 impaired ATR–ATM DNA damage signaling in response to UV radiation, as evident by impaired phosphorylation of Chk1 and p53. Subsequently, another group has further generalized the importance of RNF43 to the development of sporadic MSI-H colorectal cancers.8 Performing whole-exome sequencing on 185 formalin-fixed, paraffin-embedded colon cancers from two Harvard cohorts, Giannakis et al. discovered deleterious somatic mutations in RNF43 to be present in 18.9% of these cancers, in addition to being frequently mutated in endometrial cancers. Interestingly, 50% of the deleterious mutations discovered were frameshift mutations occurring at microsatellite loci within the gene. Validation of a small subset of tumors by next-generation sequencing or Sanger sequencing demonstrated an overall accuracy of 97% for the RNF43 mutation calls made by software. To replicate these results, the authors reanalyzed 222 colorectal cancer cases from The Cancer Genome Atlas.9 RNF43 mutations were present reliably in 17.6% of cases, and 49 cases were from the initial publication. The discrepancy between these results and previously published analyses of the TCGA data set may be attributable to newer algorithms in the detection of significant insertion and deletion events, which continue to be an ongoing challenge in their accuracy compared with single-nucleotide polymorphisms. Under prior methodologies, many true mutations at microsatellite sites were falsely discarded as errors due to their resemblance to sequencing artifacts caused by polymerase slippage during the exome enrichment step. Consistent with the importance of this RNF43 in the serrated pathway, these mutations were particularly enriched in those tumors with MSI-H status, occurring in ~80% of this subset of colorectal cancers (P

Background: Colorectal cancer (CRC) is a major cause of morbidity and mortality. Previous genome-wide association studies (GWAS) have identified a large number of single nucleotide polymorphisms (SNPs) associated with CRC, at least one of which has also been found to be associated with CRC survival. Furthermore, some SNPs have demonstrated risk associations with multiple cancers (i.e. pleiotropy), including CRC. Together, this raises the possibility that SNPs associated with risk of other cancers may also be associated with survival after a diagnosis of CRC. To investigate this question, we evaluated 526 SNPs reported as strongly associated with risk of any type of cancer in the National Human Genome Research Institute GWAS catalog (as of 11/13/2013) for an association with CRC-specific and overall survival. This study utilized data available from multiple studies in the Genetic Epidemiology of Colorectal Cancer Consortium (GECCO). Methods: We evaluated 526 SNPs associated with risk of cancers other than CRC in six studies participating in GECCO: the Health Professionals Follow-up Study; the Nurses' Health Study; the Physicians' Health Study; the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial; the VITamins And Lifestyle Study; and the Women's Health Initiative. A total of 3,494 colorectal cancer cases were evaluated, of whom 1,223 (35%) died (830 from CRC, 24%) during follow-up (average median follow-up time of 6.8 years). Cox proportional hazards regression was used to calculate the per-allele hazard ratio (HR) and 95% confidence interval (95% CI) for the association between each SNP and CRC-specific or overall survival, adjusting for age at diagnosis, sex, study sample, and the first three principal components of genetic ancestry. Results: After Bonferroni correction for multiple comparisons (P = 0.05/526 = 9.51e-5), no SNPs were statistically significantly associated with either CRC-specific or overall survival. For CRC-specific survival, 35 SNPs showed a nominal association (p Conclusion: These preliminary results broadly suggest that CRC-specific and overall survival do not appear to be strongly associated with genetic variants related to incidence for other cancers. However, some suggestive evidence of nominal associations with survival supports further investigation. Planned future steps include the incorporation of two additional studies (Cancer Prevention Study II; Diet, Activity, and Lifestyle Study), as well as analyses stratified by factors such as cancer site, stage at diagnosis, and sex. Citation Format: Jonathan M. Kocarnik, Michael N. Passarelli, Amanda I. Phipps, Andrew T. Chan, Manish Gala, Amit Joshi, Peter T. Campbell, Martha L. Slattery, John Potter, Emily White, Sonja Berndt, Ulrike Peters, Polly A. Newcomb. Colorectal cancer survival is not associated with genetic variants related to risk of other cancers: The GECCO study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2187. doi:10.1158/1538-7445.AM2014-2187

Corrigendum: Induction of interleukin-8 preserves the angiogenic response in HIF-1α–deficient colon cancer cells