Decreased Risk of Esophageal Adenocarcinoma After Gastric Bypass Surgery in a Cohort Study From 3 Nordic Countries.

OBJECTIVE: The objective of this study was to test the hypothesis that bariatric surgery decreases the risk of esophageal and cardia adenocarcinoma. BACKGROUND: Obesity is strongly associated with esophageal adenocarcinoma and moderately with cardia adenocarcinoma, but whether weight loss prevents these tumors is unknown. METHODS: This population-based cohort study included patients with an obesity diagnosis in Sweden, Finland, or Denmark. Participants were divided into a bariatric surgery group and a nonoperated group. The incidence of esophageal and cardia adenocarcinoma (ECA) was first compared with the corresponding background population by calculating standardized incidence ratios (SIR) with 95% CIs. Second, the bariatric surgery group and the nonoperated group were compared using multivariable Cox regression, providing hazard ratios (HR) with 95% CI, adjusted for sex, age, comorbidity, calendar year, and country. RESULTS: Among 748,932 participants with an obesity diagnosis, 91,731 underwent bariatric surgery, predominantly gastric bypass (n=70,176; 76.5%). The SIRs of ECA decreased over time after gastric bypass, from SIR=2.2 (95% CI, 0.9-4.3) after 2 to 5 years to SIR=0.6 (95% CI, <0.1-3.6) after 10 to 40 years. Gastric bypass patients were also at a decreased risk of ECA compared with nonoperated patients with obesity [adjusted HR=0.6, 95% CI, 0.4-1.0 (0.98)], with decreasing point estimates over time. Gastric bypass was followed by a strongly decreased adjusted risk of esophageal adenocarcinoma (HR=0.3, 95% CI, 0.1-0.8) but not of cardia adenocarcinoma (HR=0.9, 95% CI, 0.5-1.6), when analyzed separately. There were no consistent associations between other bariatric procedures (mainly gastroplasty, gastric banding, sleeve gastrectomy, and biliopancreatic diversion) and ECA. CONCLUSIONS: Gastric bypass surgery may counteract the development of esophageal adenocarcinoma in morbidly obese individuals.

Multicenter, Prospective Cohort Study of Oesophageal Injuries and Related Clinical Outcomes (MUSOIC study).

OBJECTIVE: To identify prognostic factors associated with 90-day mortality in patients with oesophageal perforation (OP), and characterize the specific timeline from presentation to intervention, and its relation to mortality. BACKGROUND: OP is a rare gastro-intestinal surgical emergency with a high mortality rate. However, there is no updated evidence on its outcomes in the context of centralized esophago-gastric services; updated consensus guidelines; and novel non-surgical treatment strategies. METHODS: A multi-center, prospective cohort study involving eight high-volume esophago-gastric centers (January 2016 to December 2020) was undertaken. The primary outcome measure was 90-day mortality. Secondary measures included length of hospital and ICU stay, and complications requiring re-intervention or re-admission. Mortality model training was performed using random forest, support-vector machines, and logistic regression with and without elastic net regularisation. Chronological analysis was performed by examining each patient's journey timepoint with reference to symptom onset. RESULTS: The mortality rate for 369 patients included was 18.9%. Patients treated conservatively, endoscopically, surgically, or combined approaches had mortality rates of 24.1%, 23.7%, 8.7%, and 18.2%, respectively. The predictive variables for mortality were Charlson comorbidity index, haemoglobin count, leucocyte count, creatinine levels, cause of perforation, presence of cancer, hospital transfer, CT findings, whether a contrast swallow was performed, and intervention type. Stepwise interval model showed that time to diagnosis was the most significant contributor to mortality. CONCLUSIONS: Non-surgical strategies have better outcomes and may be preferred in selected cohorts to manage perforations. Outcomes can be significantly improved through better risk-stratification based on afore-mentioned modifiable risk factors.

Delayed Surgical Intervention After Chemoradiotherapy in Esophageal Cancer: (DICE) Study.

OBJECTIVE: To determine the impact of delayed surgical intervention following chemoradiotherapy (CRT) on survival from esophageal cancer. BACKGROUND: CRT is a core component of multimodality treatment for locally advanced esophageal cancer. The timing of surgery following CRT may influence the probability of performing an oncological resection and the associated operative morbidity. METHODS: This was an international, multicenter, cohort study, including patients from 17 centers who received CRT followed by surgery between 2010 and 2020. In the main analysis, patients were divided into 4 groups based upon the interval between CRT and surgery (0-50, 51-100, 101-200, and >200 days) to assess the impact upon 90-day mortality and 5-year overall survival. Multivariable logistic and Cox regression provided hazard ratios (HRs) with 95% CIs adjusted for relevant patient, oncological, and pathologic confounding factors. RESULTS: A total of 2867 patients who underwent esophagectomy after CRT were included. After adjustment for relevant confounders, prolonged interval following CRT was associated with an increased 90-day mortality compared with 0 to 50 days (reference): 51 to 100 days (HR=1.54, 95% CI: 1.04-2.29), 101 to 200 days (HR=2.14, 95% CI: 1.37-3.35), and >200 days (HR=3.06, 95% CI: 1.64-5.69). Similarly, a poorer 5-year overall survival was also observed with prolonged interval following CRT compared with 0 to 50 days (reference): 101 to 200 days (HR=1.41, 95% CI: 1.17-1.70), and >200 days (HR=1.64, 95% CI: 1.24-2.17). CONCLUSIONS: Prolonged interval following CRT before esophagectomy is associated with increased 90-day mortality and poorer long-term survival. Further investigation is needed to understand the mechanism that underpins these adverse outcomes observed with a prolonged interval to surgery.

Quantifying the burden of survivorship associated with infrarenal abdominal aortic aneurysms.

OBJECTIVES: Survivorship encompasses the physical, psychological, social, functional, and economic experience of a living with a chronic condition for both the patient and their caregiver. It is made up of nine distinct domains and remains understudied in nononcological pathologies, including infrarenal abdominal aortic aneurysmal disease (AAA). This review aims to quantify the extent to which existing AAA literature addresses the burden of survivorship. METHODS: The MEDLINE, EMBASE, and PsychINFO databases were searched from 1989 through September 2022. Randomized controlled trials, observational studies, and case series were included. Eligible studies had to detail outcomes related to survivorship in patients with AAA. Owing to the heterogeneity between studies and outcomes, no meta-analysis was conducted. Study quality was assessed with specific risk of bias tools. RESULTS: A total of 158 studies were included. Of these, only five (treatment complications, physical functioning, comorbidities, caregivers, and mental health) of the nine domains of survivorship have been studied previously. The available evidence is of variable quality; most studies display a moderate to high risk of bias, are of an observational study design, are based within a limited number of countries, and consist of an insufficient follow-up period. The most frequent complication after EVAR was endoleak. EVAR is associated with poorer long-term outcomes compared with open surgical repair in most studies retrieved. EVAR showed better outcomes in regard to physical functioning in the short term, but this advantage was lost in the long term. The most common comorbidity studied was obesity. No significant differences were found between open surgical repair and EVAR in terms of impact on caregivers. Depression is associated with various comorbidities and increased the risk of a nonhospital discharge. CONCLUSIONS: This review highlights the absence of robust evidence regarding survivorship in AAA. As a result, contemporary treatment guidelines rely on historic quality-of-life data that are narrow in scope and nonrepresentative of contemporary clinical practice. As such, there is an urgent need to reevaluate the aims and methodology associated with traditional quality-of-life research moving forward.

The Impact of Obesity on the Resolution of Hypertension Following Adrenalectomy for Primary Hyperaldosteronism.

BACKGROUND: This study aims to determine the impact of patient obesity on the resolution of hypertension and pill burden post-adrenalectomy for PA. Primary hyperaldosteronism (PA) is the most common cause of secondary hypertension that may be remedied with surgery (unilateral adrenalectomy). Obesity may independently cause hypertension through several mechanisms including activation of the renin-angiotensin-aldosterone pathway. The influence of obesity on the efficacy of adrenalectomy in PA has not been established. METHODS: This is a retrospective analysis of prospectively collected data on patients undergoing adrenalectomy for PA at a single, tertiary-care surgical centre from January 2015 to December 2020. Electronic health records of patients were screened to collect relevant data. The primary outcomes of the study include post-operative blood pressure, the reduction in the number of anti-hypertensive medications and potassium supplementation burden post-adrenalectomy. RESULTS: Fifty-three patients were included in the final analysis. There was a significant reduction in the blood pressure and the number of anti-hypertensive medications in all patients after adrenalectomy (p < 0.001). Of the 34 patients (64.2%) with pre-operative hypokalaemia, all became normokalaemic and were able to stop supplementation. However obese patients required more anti-hypertensive medications to achieve an acceptable blood pressure than overweight or normal BMI patients (p < 0.01). Multivariate logistic regression analysis showed that male gender and BMI were independent predictors of resolution of hypertension (p <0.01). CONCLUSION: Unilateral adrenalectomy improves the management of hypertension and hypokalaemia when present in patients with PA. However, obesity has an independent deleterious impact on improvement in blood pressure post-adrenalectomy for PA.

The role of artificial intelligence in the endoscopic diagnosis of esophageal cancer: a systematic review and meta-analysis.

Early detection of esophageal cancer is limited by accurate endoscopic diagnosis of subtle macroscopic lesions. Endoscopic interpretation is subject to expertise, diagnostic skill, and thus human error. Artificial intelligence (AI) in endoscopy is increasingly bridging this gap. This systematic review and meta-analysis consolidate the evidence on the use of AI in the endoscopic diagnosis of esophageal cancer. The systematic review was carried out using Pubmed, MEDLINE and Ovid EMBASE databases and articles on the role of AI in the endoscopic diagnosis of esophageal cancer management were included. A meta-analysis was also performed. Fourteen studies (1590 patients) assessed the use of AI in endoscopic diagnosis of esophageal squamous cell carcinoma-the pooled sensitivity and specificity were 91.2% (84.3-95.2%) and 80% (64.3-89.9%). Nine studies (478 patients) assessed AI capabilities of diagnosing esophageal adenocarcinoma with the pooled sensitivity and specificity of 93.1% (86.8-96.4) and 86.9% (81.7-90.7). The remaining studies formed the qualitative summary. AI technology, as an adjunct to endoscopy, can assist in accurate, early detection of esophageal malignancy. It has shown superior results to endoscopists alone in identifying early cancer and assessing depth of tumor invasion, with the added benefit of not requiring a specialized skill set. Despite promising results, the application in real-time endoscopy is limited, and further multicenter trials are required to accurately assess its use in routine practice.

Evaluation of tumor regression by neoadjuvant chemotherapy regimens for esophageal adenocarcinoma: a systematic review and meta-analysis.

Locally advanced esophageal adenocarcinomas (EACs) are treated with multimodal therapy, namely surgery, neoadjuvant chemotherapy (NAC) or chemoradiotherapy (CRT) depending on patient and tumor level factors. Yet, there is little consensus on choice of the optimum systemic therapy. To compare the pathological complete response (pCR) after FLOT, non-FLOT-based chemotherapy and chemoradiotherapy regimes in patients with EACs. A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Studies were included if they had investigated the use of chemo(radio)therapy regimens in the neoadjuvant setting for EAC and reported the pCR rates. A meta-analysis of proportions was performed to compare the pooled pCR rates between FLOT, non-FLOT and CRT cohorts. We included 22 studies that described tumor regression post-NAC. Altogether, 1,056 patients had undergone FLOT or DCF regimes, while 1,610 patients had received ECF or ECX. The pCR rates ranged from 3.3% to 54% for FLOT regimes, while pCR ranged between 0% and 31% for ECF/ECX protocols. Pooled random-effects meta-meta-analysis of proportions showed a statistically significant higher incidence of pCR in FLOT-based chemotherapy at 0.148 (95%CI: 0.080, 0.259) compared with non-FLOT-based chemotherapy at 0.074 (95%CI: 0.042, 0.129). However, pCR rates were significantly highest at 0.250 (95%CI: 0.202, 0.306) for CRT. The use of enhanced FLOT-based regimens have improved the pCR rates for chemotherapeutic regimes but still falls short of pathological outcomes from CRT. Further work can characterize clinical responses to neoadjuvant therapy and determine whether an organ-preservation strategy is feasible.

Performance of radiomics-based artificial intelligence systems in the diagnosis and prediction of treatment response and survival in esophageal cancer: a systematic review and meta-analysis of diagnostic accuracy.

Radiomics can interpret radiological images with more detail and in less time compared to the human eye. Some challenges in managing esophageal cancer can be addressed by incorporating radiomics into image interpretation, treatment planning, and predicting response and survival. This systematic review and meta-analysis provides a summary of the evidence of radiomics in esophageal cancer. The systematic review was carried out using Pubmed, MEDLINE, and Ovid EMBASE databases-articles describing radiomics in esophageal cancer were included. A meta-analysis was also performed; 50 studies were included. For the assessment of treatment response using 18F-FDG PET/computed tomography (CT) scans, seven studies (443 patients) were included in the meta-analysis. The pooled sensitivity and specificity were 86.5% (81.1-90.6) and 87.1% (78.0-92.8). For the assessment of treatment response using CT scans, five studies (625 patients) were included in the meta-analysis, with a pooled sensitivity and specificity of 86.7% (81.4-90.7) and 76.1% (69.9-81.4). The remaining 37 studies formed the qualitative review, discussing radiomics in diagnosis, radiotherapy planning, and survival prediction. This review explores the wide-ranging possibilities of radiomics in esophageal cancer management. The sensitivities of 18F-FDG PET/CT scans and CT scans are comparable, but 18F-FDG PET/CT scans have improved specificity for AI-based prediction of treatment response. Models integrating clinical and radiomic features facilitate diagnosis and survival prediction. More research is required into comparing models and conducting large-scale studies to build a robust evidence base.

Research protocol for the Paraesophageal hernia symptom tool, a prospective multi-center cohort study to identify the need and threshold for surgery and assess the symptom response to surgery.

Large hiatus hernias with a significant paraesophageal component (types II-IV) have a range of insidious symptoms. Management of symptomatic hernias includes conservative treatment or surgery. Currently, there is no paraesophageal hernia disease-specific symptom questionnaire. As a result, many clinicians rely on the health-related quality of life questionnaires designed for gastro-esophageal reflux disease (GORD) to assess patients with hiatal hernias pre- and postoperatively. In view of this, a paraesophageal hernia symptom tool (POST) was designed. This POST questionnaire now requires validation and assessment of clinical utility. Twenty-one international sites will recruit patients with paraesophageal hernias to complete a series of questionnaires over a five-year period. There will be two cohorts of patients-patients with paraesophageal hernias undergoing surgery and patients managed conservatively. Patients are required to complete a validated GORD-HRQL, POST questionnaire, and satisfaction questionnaire preoperatively. Surgical cohorts will also complete questionnaires postoperatively at 4-6 weeks, 6 months, 12 months, and then annually for a total of 5 years. Conservatively managed patients will repeat questionnaires at 1 year. The first set of results will be released after 1 year with complete data published after a 5-year follow-up. The main results of the study will be patient's acceptance of the POST tool, clinical utility of the tool, assessment of the threshold for surgery, and patient symptom response to surgery. The study will validate the POST questionnaire and identify the relevance of the questionnaire in routine management of paraesophageal hernias.

Length of biliopancreatic limb in Roux-en-Y gastric bypass and its impact on post-operative outcomes in metabolic and obesity surgery-systematic review and meta-analysis.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is a gold-standard procedure for treatment of obesity and associated comorbidities. No consensus on the optimal design of this operation has been achieved, with various lengths of bypassed small bowel limb lengths being used by bariatric surgeons. This aim of this systematic review and meta-analysis was to determine whether biliopancreatic limb (BPL) length in RYGB affects postoperative outcomes including superior reduction in weight, body mass index (BMI), and resolution of metabolic comorbidities associated with obesity. METHODS: A systematic search of the literature was conducted up until 1st June 2021. Meta-analysis of primary outcomes was performed utilising a random-effects model. Statistical significance was determined by p value < 0.05. RESULTS: Ten randomised controlled trials were included in the final quantitative analysis. No difference in outcomes following short versus long BLP in RYGB was identified at 12-72 months post-operatively, namely in BMI reduction, remission or improvement of type 2 diabetes mellitus, hypertension, dyslipidaemia, and complications (p > 0.05). Even though results of four studies showed superior total body weight loss in the long BPL cohorts at 24 months post-operatively (pooled mean difference -6.92, 95% CI -12.37, -1.48, p = 0.01), this outcome was not observed at any other timepoint. CONCLUSION: Based on the outcomes of the present study, there is no definitive evidence to suggest that alteration of the BPL affects the quantity of weight loss or resolution of co-existent metabolic comorbidities associated with obesity.

ASO Author Reflections: Applications of Artificial Intelligence in Oesophago-Gastric Malignancies-Present Work and Future Directions.

Our paper highlights the use of artificial intelligence (AI) in oesophageal and gastric malignancies with acceptable levels of accuracy for both diagnostic and surveillance purposes. Here, we comment on the past, present and future work necessary for incorporating AI into the clinical framework and practice.

Diagnostic Performance of Artificial Intelligence-Centred Systems in the Diagnosis and Postoperative Surveillance of Upper Gastrointestinal Malignancies Using Computed Tomography Imaging: A Systematic Review and Meta-Analysis of Diagnostic Accuracy.

BACKGROUND: Upper gastrointestinal cancers are aggressive malignancies with poor prognosis, even following multimodality therapy. As such, they require timely and accurate diagnostic and surveillance strategies; however, such radiological workflows necessitate considerable expertise and resource to maintain. In order to lessen the workload upon already stretched health systems, there has been increasing focus on the development and use of artificial intelligence (AI)-centred diagnostic systems. This systematic review summarizes the clinical applicability and diagnostic performance of AI-centred systems in the diagnosis and surveillance of esophagogastric cancers. METHODS: A systematic review was performed using the MEDLINE, EMBASE, Cochrane Review, and Scopus databases. Articles on the use of AI and radiomics for the diagnosis and surveillance of patients with esophageal cancer were evaluated, and quality assessment of studies was performed using the QUADAS-2 tool. A meta-analysis was performed to assess the diagnostic accuracy of sequencing methodologies. RESULTS: Thirty-six studies that described the use of AI were included in the qualitative synthesis and six studies involving 1352 patients were included in the quantitative analysis. Of these six studies, four studies assessed the utility of AI in gastric cancer diagnosis, one study assessed its utility for diagnosing esophageal cancer, and one study assessed its utility for surveillance. The pooled sensitivity and specificity were 73.4% (64.6-80.7) and 89.7% (82.7-94.1), respectively. CONCLUSIONS: AI systems have shown promise in diagnosing and monitoring esophageal and gastric cancer, particularly when combined with existing diagnostic methods. Further work is needed to further develop systems of greater accuracy and greater consideration of the clinical workflows that they aim to integrate within.

Physiotherapy Regimens in Esophagectomy and Gastrectomy: a Systematic Review and Meta-Analysis.

BACKGROUND: Esophageal and gastric cancer surgery are associated with considerable morbidity, specifically postoperative pulmonary complications (PPCs), potentially accentuated by underlying challenges with malnutrition and cachexia affecting respiratory muscle mass. Physiotherapy regimens aim to increase the respiratory muscle strength and may prevent postoperative morbidity. OBJECTIVE: The aim of this study was to assess the impact of physiotherapy regimens in patients treated with esophagectomy or gastrectomy. METHODS: An electronic database search was performed in the MEDLINE, EMBASE, CENTRAL, CINAHL and Pedro databases. A meta-analysis was performed to assess the impact of physiotherapy on the functional capacity, incidence of PPCs and postoperative morbidity, in-hospital mortality rate, length of hospital stay (LOS) and health-related quality of life (HRQoL). RESULTS: Seven randomized controlled trials (RCTs) and seven cohort studies assessing prehabilitation totaling 960 patients, and five RCTs and five cohort studies assessing peri- or postoperative physiotherapy with 703 total patients, were included. Prehabilitation resulted in a lower incidence of postoperative pneumonia and morbidity (Clavien-Dindo score ≥ II). No difference was observed in functional exercise capacity and in-hospital mortality following prehabilitation. Meanwhile, peri- or postoperative rehabilitation resulted in a lower incidence of pneumonia, shorter LOS, and better HRQoL scores for dyspnea and physical functioning, while no differences were found for the QoL summary score, global health status, fatigue, and pain scores. CONCLUSION: This meta-analysis suggests that implementing an exercise intervention may be beneficial in both the preoperative and peri- or postoperative periods. Further investigation is needed to understand the mechanism through which exercise interventions improve clinical outcomes and which patient subgroup will gain the maximal benefit.

Effect of primary tumour resection without curative intent in patients with metastatic neuroendocrine tumours of the small intestine and right colon: meta-analysis.

BACKGROUND: Patients with small intestinal neuroendocrine tumours (siNETs) usually present with advanced disease. Primary tumour resection without curative intent is controversial in patients with metastatic siNETs. The aim of this meta-analysis was to investigate survival after primary tumour resection without curative intent compared with no resection in patients with metastatic siNETs. METHODS: A systematic literature search was performed, using MEDLINE® (PubMed), Embase®, Web of Science, and the Cochrane Library up to 25 February 2021. Studies were included if survival after primary tumour resection versus no resection in patients with metastatic siNETs was reported. Results were pooled in a random-effects meta-analysis, and are reported as hazard ratios (HRs) with 95 per cent confidence intervals. Sensitivity analyses were undertaken to enable comment on the impact of important confounders. RESULTS: After screening 3659 abstracts, 16 studies, published between 1992 and 2021, met the inclusion criteria, with a total of 9428 patients. Thirteen studies reported HRs adjusted for important confounders and were included in the meta-analysis. Median overall survival was 112 (i.q.r. 82-134) months in the primary tumour resection group compared with 60 (74-88) months in the group without resection. Five-year overall survival rates were 74 (i.q.r. 67-77) and 44 (34-45) per cent respectively. Primary tumour resection was associated with improved survival compared with no resection (HR 0.55, 95 per cent c.i. 0.47 to 0.66). This effect remained in sensitivity analyses. CONCLUSION: Primary tumour resection is associated with increased survival in patients with advanced, metastatic siNETs, even after adjusting for important confounders.

Association of Upper Gastrointestinal Surgery of Great Britain and Ireland (AUGIS)/Perioperative Quality Initiative (POQI) consensus statement on intraoperative and postoperative interventions to reduce pulmonary complications after oesophagectomy.

BACKGROUND: Pulmonary complications are the most common morbidity after oesophagectomy, contributing to mortality and prolonged postoperative recovery, and have a negative impact on health-related quality of life. A variety of single or bundled interventions in the perioperative setting have been developed to reduce the incidence of pulmonary complications. Significant variation in practice exists across the UK. The aim of this modified Delphi consensus was to deliver clear evidence-based consensus recommendations regarding intraoperative and postoperative care that may reduce pulmonary complications after oesophagectomy. METHODS: With input from a multidisciplinary group of 23 experts in the perioperative management of patients undergoing surgery for oesophageal cancer, a modified Delphi method was employed. Following an initial systematic review of relevant literature, a range of anaesthetic, surgical, and postoperative care interventions were identified. These were then discussed during a two-part virtual conference. Recommendation statements were drafted, refined, and agreed by all attendees. The level of evidence supporting each statement was considered. RESULTS: Consensus was reached on 12 statements on topics including operative approach, pyloric drainage strategies, intraoperative fluid and ventilation strategies, perioperative analgesia, postoperative feeding plans, and physiotherapy interventions. Seven additional questions concerning the perioperative management of patients undergoing oesophagectomy were highlighted to guide future research. CONCLUSION: Clear consensus recommendations regarding intraoperative and postoperative interventions that may reduce pulmonary complications after oesophagectomy are presented.

The role of the colonic microbiota and bile acids in colorectal cancer.

PURPOSE OF REVIEW: Colorectal cancer (CRC) is the third most common cancer and the second most common cause of cancer-related deaths. Of the various established risk factors for this aggressive condition, diet is a notable modifiable risk factor. This review aims to summarize the mounting evidence to suggest the role of diet, the microbiota and their cross-talk in modulating an individual's risk of developing CRC. RECENT FINDINGS: Specifically, the metabolism of bile acids and its symbiosis with the microbiota has gained weight given its basis on a high meat, high fat, and low fibre diet that is present in populations with the highest risk of CRC. Bacteria modify bile acids that escape enterohepatic circulation to increase the diversity of the human bile acid pool. The production of microbial bile acids contributes to this as well. Epidemiological studies have shown that changing the diet results in different levels and composition of bile acids, which has in turn modified the risk of CRC at a population level. Evidence to identify underlying mechanisms have tied into the microbiota-led digestions of various foods into fatty acids that feedback into bile acid physiology as well as modulation of endogenous receptors for bile acids. SUMMARY: There is adequate evidence to support the role of microbiota in in the metabolism of bile acids, and how this relates to colorectal cancer. Further work is necessary to identify specific bacteriome involved and their underlying mechanistic pathways.

Can we predict the progression of premalignant pancreatic cystic tumors to ductal adenocarcinoma?

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent malignant pancreatic tumor. Few studies have shown how often PDACs arise from cystic precursor lesions. This special report aims to summarize the evidence on the progression of precancerous lesions to PDAC. A review of the literature found four studies that discussed pancreatic intraepithelial lesions (PanINs), three that discussed mucinous cystic neoplasms (MCN) and five that discussed intraductal papillary neoplasms (IPMNs). PanINs were the most common precursors lesion, with approximately 80% of PDACs originating from this lesion. The lack of evidence characterizing the features of PDAC precursor cystic lesions potentially leads to a subset of patients undergoing surgery unnecessarily. Advancements in molecular techniques could allow the study of cystic lesions at a genetic level, leading to more personalized management.

Cancer arising from the ducts within the pancreas is the most common type of pancreatic cancer. Some cancers develop from precancerous changes, but these are not currently well described. Therefore, we have summarized the existing knowledge on the precancerous changes causing pancreatic cancer. We found three main precancerous changes: pancreatic intraepithelial lesions; mucinous cystic neoplasms; and intraductal papillary neoplasms. Pancreatic intraepithelial lesions were the most common pancreatic precancerous lesion, leading to 80% of cancers of the pancreatic ducts. A few studies indicate that patients would benefit from surgery to remove precancerous lesions. We believe that, due to advances in genetic studies, personalized strategies for treating pancreatic cancers will emerge in the future.

Clinical utility and applicability of circulating tumor DNA testing in esophageal cancer: a systematic review and meta-analysis.

Esophageal cancer is an aggressive malignancy with a relatively poor prognosis even after multimodality therapy. Currently, patients undergo a series of investigations that can be invasive and costly or pose secondary risks to their health. In other malignancies, liquid biopsies of circulating tumor DNA (ctDNA) are used in clinical practice for diagnostic and surveillance purposes. This systematic review summarizes the latest evidence for the clinical applicability of ctDNA technology in esophageal cancer. A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Articles were evaluated for the use of ctDNA for diagnosis and monitoring of patients with esophageal cancer. Quality assessment of studies was performed using the QUADAS-2 tool. A meta-analysis was performed to assess the diagnostic accuracy of sequencing methodologies. We included 15 studies that described the use of ctDNA technology in the qualitative synthesis and eight studies involving 414 patients in the quantitative analysis. Of these, four studies assessed its utility in cancer diagnosis, while four studies evaluated its use for prognosis and monitoring. The pooled sensitivity and specificity for diagnostic studies were 71.0% (55.7-82.6%) and 98.6% (33.9-99.9%), while the pooled sensitivity and specificity for surveillance purposes were 48.9% (29.4-68.8%) and 95.5% (90.6-97.9%). ctDNA technology is an acceptable method for diagnosis and monitoring with a moderate sensitivity and high specificity that is enhanced in combination with current imaging methods. Further work should demonstrate the practical integration of ctDNA in the diagnostic and surveillance clinical pathway.

Evaluation of post-operative surveillance strategies for esophageal and gastric cancers: a systematic review and meta-analysis.

BACKGROUND: There is no consensus or guidelines internationally to inform clinicians of how patients should be monitored for recurrence after esophagogastric resections. AIM: This systematic review and meta-analysis summarizes the latest evidence investigating the usefulness of surveillance protocols in patients who underwent esophagectomy or gastrectomy. METHODS: A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Articles were evaluated for the use of surveillance strategies including history-taking, physical examination, imaging modalities and endoscopy for monitoring patients post-gastrectomy or esophagectomy. Studies that compared surveillance strategies and reported detection of recurrence and post-recurrence survival were also included in the meta-analysis. RESULTS: Fifteen studies that described a surveillance protocol for post-operative patients were included in the review. Seven studies were used in the meta-analysis. Random-effects analysis demonstrated a statistically significant higher post-recurrence survival (standardized mean difference [SMD] 14.15, 95% CI 1.40-27.26, p = 0.03) with imaging-based planned surveillance post-esophagectomy. However, the detection of recurrence (OR 1.76, 95% CI 0.78-3.97, p = 0.17) for esophageal cancers as well as detection of recurrence (OR 0.73, 95% CI 0.11-5.12, p = 0.76) and post-recurrence survival (SMD 6.42, 95% CI -2.16-18.42, p = 0.14) for gastric cancers were not significantly different with planned surveillance. CONCLUSION: There is no consensus on whether surveillance carries prognostic survival benefit or how surveillance should be carried out. Surveillance may carry prognostic benefit for patients who underwent surgery for esophageal cancer. Randomized controlled trials are required to evaluate the survival benefits of intensive surveillance strategies, determine the ideal surveillance protocol and tailor it to the appropriate population.

Evaluation of postoperative surveillance strategies for esophago-gastric cancers in the UK and Ireland.

Esophago-gastric malignancies are associated with a high recurrence rate; yet there is a lack of evidence to inform guidelines for the standardization and structure of postoperative surveillance after curatively intended treatment. This study aimed to capture the variation in postoperative surveillance strategies across the UK and Ireland, and enquire the opinions and beliefs around surveillance from practicing clinicians. A web-based survey consisting of 40 questions was sent to surgeons or allied health professionals performing or involved in surgical care for esophago-gastric cancers at high-volume centers in the UK. Respondents from each center completed the survey on what best represented their center. The first section of the survey evaluated the timing and components of follow-ups, and their variation between centers. The second section evaluated respondents perspective on how surveillance can be structured. Thirty-five respondents from 27 centers consisting 28 consultants, 6 senior trainees and 1 specialist nurse had completed the questionnaire; 45.7% of responders arranged clinical follow-up at 2-4 weeks. Twenty responders had a specific postoperative surveillance protocol for their patients. Of these, 31.4% had a standardized protocol for all patients, while 25.7% tailored it to patient needs. Patient preference, comorbidities and chance of recurrence were considered as major factors for necessitating more intense surveillance than currently practiced. There is a significant variation in how patients are monitored after surgery between centers in the UK. Randomized controlled trials are necessary to link surveillance strategies to both survival outcomes and quality of life of patients and to evaluate the prognostic value of different postoperative surveillance strategies.