Main Recommendations: The following recommendations for post-polypectomy colonoscopic surveillance apply to all patients who had one or more polyps that were completely removed during a high quality baseline colonoscopy. 1 ESGE recommends that patients with complete removal of 1 – 4 < 10 mm adenomas with low grade dysplasia, irrespective of villous components, or any serrated polyp < 10 mm without dysplasia, do not require endoscopic surveillance and should be returned to screening.Strong recommendation, moderate quality evidence.If organized screening is not available, repetition of colonoscopy 10 years after the index procedure is recommended.Strong recommendation, moderate quality evidence. 2 ESGE recommends surveillance colonoscopy after 3 years for patients with complete removal of at least 1 adenoma ≥ 10 mm or with high grade dysplasia, or ≥ 5 adenomas, or any serrated polyp ≥ 10 mm or with dysplasia. Strong recommendation, moderate quality evidence. 3 ESGE recommends a 3 – 6-month early repeat colonoscopy following piecemeal endoscopic resection of polyps ≥ 20 mm.Strong recommendation, moderate quality evidence. A first surveillance colonoscopy 12 months after the repeat colonoscopy is recommended to detect late recurrence.Strong recommendation, high quality evidence. 4 If no polyps requiring surveillance are detected at the first surveillance colonoscopy, ESGE suggests to perform a second surveillance colonoscopy after 5 years. Weak recommendation, low quality evidence.After that, if no polyps requiring surveillance are detected, patients can be returned to screening. 5 ESGE suggests that, if polyps requiring surveillance are detected at first or subsequent surveillance examinations, surveillance colonoscopy may be performed at 3 years. Weak recommendation, low quality evidence.A flowchart showing the recommended surveillance intervals is provided (Fig. 1).

Research conducted during the past 30 years has increased our understanding of the mechanisms involved in colorectal cancer initiation and development. The findings have demonstrated the existence of at least three pathways: chromosomal instability, microsatellite instability and CpG island methylator phenotype. Importantly, new studies have shown that inflammation and microRNAs contribute to colorectal carcinogenesis. Recent data have demonstrated that several genetic and epigenetic changes are important in determining patient prognosis and survival. Furthermore, some of these mechanisms are related to patients’ response to drugs, such as aspirin, which could be used for both chemoprevention and treatment in specific settings. Thus, in the near future, we could be able to predict disease behavior based on molecular markers found on tumors, and direct the best treatment options for patients.

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.

Main Recommendations: ESGE recommends that individuals with hereditary gastrointestinal polyposis syndromes should be surveilled in dedicated units that provide monitoring of compliance and endoscopic performance measures. Strong recommendation, moderate quality of evidence, level of agreement 90 %.ESGE recommends performing esophagogastroduodenoscopy, small-bowel examination, and/or colonoscopy earlier than the planned surveillance procedure if a patient is symptomatic. Strong recommendation, low quality of evidence, level of agreement 100 %.

In the human DNA mismatch repair (MMR) system, hMSH2 forms the hMutSα and hMutSβ complexes with hMSH6 and hMSH3, respectively, whereas hMLH1 and hPMS2 form the hMutLα heterodimer. These complexes, together with other components in the MMR system, correct single-base mismatches and small insertion/deletion loops that occur during DNA replication. Microsatellite instability (MSI) occurs when the loops in DNA microsatellites are not corrected because of a malfunctioning MMR system. Low-frequency MSI (MSI-L) is seen in some chronically inflamed tissues in the absence of genetic inactivation of the MMR system. We hypothesize that oxidative stress associated with chronic inflammation might damage protein components of the MMR system, leading to its functional inactivation. In this study, we demonstrate that noncytotoxic levels of H₂O₂ inactivate both single-base mismatch and loop repair activities of the MMR system in a dose-dependent fashion. On the basis of in vitro complementation assays using recombinant MMR proteins, we show that this inactivation is most likely due to oxidative damage to hMutSα, hMutSβ, and hMutLα protein complexes. We speculate that inactivation of the MMR function in response to oxidative stress may be responsible for the MSI-L seen in nonneoplastic and cancer tissues associated with chronic inflammation.

Obesity is among the fastest growing diseases worldwide; treatment is inadequate, and associated disorders, including gastrointestinal cancers, have high morbidity and mortality. An increased understanding of the mechanisms of obesity-induced carcinogenesis is required to develop methods to prevent or treat these cancers. In this report, we review the mechanisms of obesity-associated colorectal, esophageal, gastric, and pancreatic cancers and potential treatment strategies.