How achievable are STRIDE-II treatment targets in real-world practice and do they predict long-term treatment outcomes?

Objective: The second iteration of the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE-II) initiative recommends use of the Simple Endoscopic Score for Crohn's disease (SES-CD) as a treatment target for patients with CD. We aimed to assess whether the STRIDE-II endoscopic endpoints are achievable and whether the degree of mucosal healing (MH) affects long-term outcomes. Design/method: We performed a retrospective observational study between 2015 and 2022. Patients with CD who had baseline and follow-up SES-CD scores after biological therapy initiation were included. The primary outcome was treatment failure, defined as the need for: (1) change of biological therapy for active disease (2) corticosteroid use (3) CD-related hospitalisation or (4) surgery. We compared rates of treatment failure with the degree of MH achieved. Patients were followed up until treatment failure or study end (August 2022). Results: 50 patients were included and followed up for median 39.9 (34.6-48.6) months. Baseline characteristics: 62% male, median age 36.4 (27.8-43.9) years, disease distribution (L1: 4, L2: 11, L3: 35, perianal: 18). The proportion of patients achieving STRIDE-II end-points were: SES-CD≤2-25 (50%) and >50% reduction in SES-CD-35 (70%). Failure to achieve SES-CD≤2 (HR 11.62; 95% CI 3.33 to 40.56, p=0.003) or >50% improvement in SES-CD (HR 30.30; 95% CI 6.93 to 132.40, p<0.0001) predicted treatment failure. Conclusion: Use of SES-CD is feasible in real-world clinical practice. Achieving an SES-CD≤2 or a greater than 50% reduction, as set out by STRIDE-II, is associated with reduced rates of overall treatment failure including CD-related surgery.

Positioning intestinal ultrasound in a UK tertiary centre: significant estimated clinical role and cost savings.

Objective: Intestinal ultrasound (IUS) is an inexpensive, non-invasive method of diagnosing and monitoring inflammatory bowel disease (IBD). We aimed to establish the proportion of lower gastrointestinal endoscopies (LGIEs) and magnetic resonance enterographies (MREs) that could have been performed as IUS, the potential pathology miss-rates if IUS was used and the associated cost savings. Methods: All MREs and LGIEs performed for either assessment of IBD activity or investigation of possible IBD, performed at a single UK tertiary centre in January 2018, were retrospectively reviewed against predetermined criteria for IUS suitability. Case outcomes were recorded and cost of investigation if IUS was performed instead was calculated. Results: 73 of 260 LGIEs (28.1%) and 58 of 105 MREs (55.2%) met the criteria for IUS suitability. Among potential IUS-suitable endoscopy patients, one case each of a <5 mm adenoma and sessile serrated lesion were found; no other significant pathology that would be expected to be missed with IUS was encountered. Among IUS-suitable MRE patients, no cases of isolated upper gastrointestinal inflammation likely to be missed by IUS were found, and extraintestinal findings not expected to be seen on IUS were of limited clinical significance. The predicted cost saving over 1 month if IUS was used instead was £8642, £25 866 and £5437 for MRE, colonoscopy and flexible sigmoidoscopy patients, respectively. Conclusion: There is a significant role for IUS, with annual projected cost savings of up to almost £500 000 at our centre. Non-inflammatory or non-gastrointestinal pathology predicted to be missed in this cohort was of limited clinical significance.

Regular feedback to individual endoscopists is associated with improved adenoma detection rate and other key performance indicators for colonoscopy.

Objective: Monitoring of key performance indicators (KPIs) is a vital element of endoscopy quality improvement. Adenoma detection rate (ADR) is considered the best marker for colonoscopic quality as it inversely correlates with subsequent colonic cancer incidence and mortality, while polyp detection rate (PDR) is an easier-to-calculate surrogate for ADR. This study assessed whether regular feedback to individual endoscopists about their KPIs improved departmental performance. Methods: Individual KPIs were calculated for a period of 8 years (January 2012-December 2019) and fed back to all endoscopists at 6 monthly intervals, alongside anonymised indicators for other endoscopists, aggregate departmental performance data and benchmarks. An automated natural language processing software (EndoMineR) was used to identify adenomas in pathology reports and calculate ADR. Linear regressions were calculated for departmental ADR, PDR and other KPIs at 6 monthly intervals. Results: 39 359 colonoscopies (average 2460 in every 6-month period, range 1799-3059) were performed by an average of 42 (range 34-50) endoscopists. A continuous improvement in collective performance including ADR (12.7%-21.0%, R2 0.92, p<0.001) and PDR (19.0%-29.6%, R2 0.77, p<0.001) was observed throughout the study. Other KPIs showed similar improvement. The detection of non-neoplastic polyps did not increase. When analysed separately, ADR and PDR appeared to improve for gastroenterologists and nurse endoscopists but not for surgeons. Conclusion: Regular feedback with individual and departmental KPIs was associated with improved ADR and overall performance throughout the 8-year study period. Concomitant monitoring of ADR and PDR may prevent 'gaming' behaviour and ensure that genuine improvement is achieved.

Low-cost and clinically applicable copy number profiling using repeat DNA.

BACKGROUND: Somatic copy number alterations (SCNAs) are an important class of genomic alteration in cancer. They are frequently observed in cancer samples, with studies showing that, on average, SCNAs affect 34% of a cancer cell's genome. Furthermore, SCNAs have been shown to be major drivers of tumour development and have been associated with response to therapy and prognosis. Large-scale cancer genome studies suggest that tumours are driven by somatic copy number alterations (SCNAs) or single-nucleotide variants (SNVs). Despite the frequency of SCNAs and their clinical relevance, the use of genomics assays in the clinic is biased towards targeted gene panels, which identify SNVs but provide limited scope to detect SCNAs throughout the genome. There is a need for a comparably low-cost and simple method for high-resolution SCNA profiling. RESULTS: We present conliga, a fully probabilistic method that infers SCNA profiles from a low-cost, simple, and clinically-relevant assay (FAST-SeqS). When applied to 11 high-purity oesophageal adenocarcinoma samples, we obtain good agreement (Spearman's rank correlation coefficient, rs=0.94) between conliga's inferred SCNA profiles using FAST-SeqS data (approximately £14 per sample) and those inferred by ASCAT using high-coverage WGS (gold-standard). We find that conliga outperforms CNVkit (rs=0.89), also applied to FAST-SeqS data, and is comparable to QDNAseq (rs=0.96) applied to low-coverage WGS, which is approximately four-fold more expensive, more laborious and less clinically-relevant. By performing an in silico dilution series experiment, we find that conliga is particularly suited to detecting SCNAs in low tumour purity samples. At two million reads per sample, conliga is able to detect SCNAs in all nine samples at 3% tumour purity and as low as 0.5% purity in one sample. Crucially, we show that conliga's hidden state information can be used to decide when a sample is abnormal or normal, whereas CNVkit and QDNAseq cannot provide this critical information. CONCLUSIONS: We show that conliga provides high-resolution SCNA profiles using a convenient, low-cost assay. We believe conliga makes FAST-SeqS a more clinically valuable assay as well as a useful research tool, enabling inexpensive and fast copy number profiling of pre-malignant and cancer samples.

A retrospective cohort study: pre-operative oral enteral nutritional optimisation for Crohn's disease in a UK tertiary IBD centre.

BACKGROUND: Low-quality evidence suggests that pre-operative exclusive enteral nutrition (E/EN) can improve postoperative outcomes in patients with Crohn's disease (CD). It is not standard practice in most centres. AIMS: To test the hypothesis that pre-operative EN in patients undergoing ileal/ileocolonic surgery for CD is associated with improved postoperative outcome. METHODS: We performed a single centre retrospective observational study comparing surgical outcomes in patients receiving pre-operative EN (≥600 kcal/day for ≥2 weeks) with those who received no nutritional optimisation. Consecutive adult patients undergoing ileal/ileocolonic resection from 2008 to 2020 were included. The primary outcome was postoperative complications <30 days. Secondary outcomes included EN tolerance, specific surgical complications, unplanned stoma formation, length of stay, length of bowel resected, readmission and biochemical/anthropometric changes. RESULTS: 300 surgeries were included comprising 96 without nutritional optimisation and 204 optimised cases: oral EN n = 173, additional PN n = 31 (4 of whom had received nasogastric/nasojejunal EN). 142/204 (69.6%) tolerated EN. 125/204 (61.3%) initiated EN in clinic. Patients in the optimised cohort were younger at operation and diagnosis, with an increased frequency of penetrating disease and exposure to antibiotics or biologics, and were more likely to undergo laparoscopic surgery. The optimised cohort had favourable outcomes on multivariate analysis: all complications [OR 0.29; 0.15-0.57, p < 0.001], surgical complications [OR 0.41; 95% CI 0.20-0.87, p = 0.02], non-surgical complications [OR 0.24 95% CI 0.11-0.52, p < 0.001], infective complications [OR 0.32; 95% CI 0.16-0.66, p = 0.001]. CONCLUSIONS: Oral EN was reasonably well tolerated and associated with a reduction in 30-day postoperative complications. Randomised controlled trials are required to confirm these findings.

Patient perspectives on key symptoms and preferences for follow-up after upper gastro-intestinal cancer surgery.

PURPOSE: Long-lasting symptoms and reductions in quality of life are common after oesophago-gastric surgery. Post-operative follow-up has traditionally focussed on tumour recurrence and survival, but there is a growing need to also identify and treat functional sequelae to improve patients' recovery. METHODS: An electronic survey was circulated via a British national charity for patients undergoing oesophago-gastric surgery and their families. Patients were asked about post-operative symptoms they deemed important to their quality of life, as well as satisfaction and preferences for post-operative follow-up. Differences between satisfied and dissatisfied patients with reference to follow-up were assessed. RESULTS: Among 362 respondents with a median follow-up of 58 months since surgery (range 3-412), 36 different symptoms were reported as being important to recovery and quality of life after surgery, with a median of 13 symptoms per patient. Most (84%) respondents indicated satisfaction with follow-up. Satisfied patients were more likely to have received longer follow-up (5-year or longer follow-up 60% among satisfied patients vs 27% among unsatisfied, p < 0.001). These were also less likely to have seen a dietitian as part of routine follow-up (37% vs 58%, p = 0.005). CONCLUSION: This patient survey highlights preferences regarding follow-up after oesophago-gastrectomy. Longer follow-up and dietician involvement improved patient satisfaction. Patients reported being concerned by a large number of gastrointestinal and non-gastrointestinal symptoms, highlighting the need for multidisciplinary input and a consensus on how to manage the poly-symptomatic patient.

Transition from esophagectomy to endoscopic therapy for early esophageal cancer.

BACKGROUND: To assess the outcomes of patients with early esophageal cancer and high-grade dysplasia comparing esophagectomy, the historical treatment of choice, to endoscopic eradication therapy (EET). METHODS: Retrospective cohort study of consecutive patients with early esophageal cancer/high-grade dysplasia, treated between 2000 and 2018 at a tertiary center. Primary outcomes were all-cause and disease-specific mortality assessed by multivariable Cox regression and a propensity score matching sub analysis, providing hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, tumor grade (G1/2 vs. G3), tumor stage, and lymphovascular invasion. Secondary outcomes included complications, hospital stay, and overall costs. RESULTS: Among 269 patients, 133 underwent esophagectomy and 136 received EET. Adjusted survival analysis showed no difference between groups regarding all-cause mortality (HR 1.85, 95% CI 0.73, 4.72) and disease-specific mortality (HR 1.10, 95% CI 0.26, 4.65). In-hospital and 30-day mortality was 0% in both groups. The surgical group had a significantly higher rate of complications (Clavien-Dindo ≥3 26.3% vs. endoscopic therapy 0.74%), longer in-patient stay (median 14 vs. 0 days endoscopic therapy) and higher hospital costs(£16 360 vs. £8786 per patient). CONCLUSION: This series of patients treated during a transition period from surgery to EET, demonstrates a primary endoscopic approach does not compromise oncological outcomes with the benefit of fewer complications, shorter hospital stays, and lower costs compared to surgery. It should be available as the gold standard treatment for patients with early esophageal cancer. Those with adverse prognostic features may still benefit from esophagectomy.

The effects of COVID-19 on IBD prescribing and service provision in a UK tertiary centre.

BACKGROUND: To quantify the effects of COVID-19 on our inflammatory bowel disease (IBD) unit, including service provision, prescribing practices and use of therapeutic drug monitoring (TDM). METHODS: We performed a single centre retrospective observational cohort study. Data was extracted from our IBD database, electronic patient records and radiology/endoscopy reporting systems between 16/3/20-17/4/20 and the corresponding period in 2019. RESULTS: A similar number of patients commenced biologic therapy before COVID-19 (n = 37) and during the pandemic (n = 36). Patients in the pre-COVID-19 cohort were older (median 36 vs 29 years, P = 0.009) with a longer median disease duration (9.3 vs 5.2 years, P = 0.02). During COVID-19 there was a nonsignificant increase in prescribing of vedolizumab (8/37, 22% vs 14/36, 39%, P = 0.13) and a higher proportion of patients were anti-TNF-naïve (3/17, 18% vs 18/24, 74%, P = 0.0004). There was a reduction in use of concomitant immunomodulators (22/29, 76% vs 4/34, 12%, P < 0.0001) and increased biologic use in thiopurine-naïve patients (3/37, 8% vs 15/36, 42%, P = 0.001). Use of TDM fell by 75% (240 vs 59 tests). Outpatient appointments fell by 68% and were conducted via telemedicine. MRI scanning, endoscopy, luminal surgery and inpatient numbers fell by 87%, 85%, 100% and 82% respectively. IBD Clinical Nurse Specialist and Pharmacist helpline contacts increased by 76% and 228% respectively. CONCLUSIONS: We observed prescribing differences during COVID-19, bypassing the initiation of immunomodulators and/or anti-TNF therapy in favour of vedolizumab with a reduction in immunomodulator prescribing. We also observed a rapid reorganisation of service provision, including a shift towards telemedicine and online solutions.

Uvular necrosis following diagnostic gastroscopy.

Uvular necrosis is an extremely rare complication of gastroscopy. We describe the fifth published case of uvular necrosis following an uncomplicated diagnostic gastroscopy in a young man. Presentation with severe sore throat and inability to swallow saliva occurred within 24 hours of gastroscopy and resolved with conservative treatment.

Genomics of Esophageal Cancer and Biomarkers for Early Detection.

In-depth molecular characterization of esophageal oncogenesis has improved over the recent years. Advancement in molecular biology and bioinformatics has led to better understanding of its genomic landscape. More specifically, analysis of its pathogenesis at the genetic level has uncovered the involvement of a number of tumor suppressor genes, cell cycle regulators, and receptor tyrosine kinases. Due to its poor prognosis, the development of clinically applicable biomarkers for diagnosis, progression, and treatment has been the focus of many research studies concentrating on upper gastrointestinal malignancies. As in other cancers, early detection and subsequent intervention of the preneoplastic condition significantly improves patient outcomes. Currently, clinically approved surveillance practices heavily depend on expensive, invasive, and sampling-error-prone endoscopic procedures. There is, therefore, a great demand to establish clearly reliable biomarkers that could identify those patients at higher risk of neoplastic progression and hence would greatly benefit from further monitoring and/or intervention. This chapter will present the most recent advances in the analysis of the esophageal cancer genome serving as basis for biomarker development.

The use of molecular markers in predicting dysplasia and guiding treatment.

The ability to stratify patients based on the risk of progression to oesophageal adenocarcinoma would provide benefit to patients as well as deliver a more cost effective surveillance programme. Current practice is to survey all patients with Barrett's oesophagus (BO) and use histological diagnoses to guide further management. However, reliance on histology alone has its drawbacks. We are currently unable to reliably stratify the risk of progression of patients with non-dysplastic BO based on any particular histological feature. There is also considerable variability in histological interpretation. An obvious recourse has been to rely on identifying molecular features possibly as an adjunct to histology, to better diagnose and stratify patients. To this end, p53 immunohistochemistry can be used as a useful adjunct to risk stratify and clarify histological grades, particularly low-grade dysplasia. Other markers of progression, although not yet in a clinically applicable format, are promising. Measurements of promoter methylation and also genomic instability such as loss of heterozygosity and copy number alterations show promise especially as high throughput genetic technologies reach maturity. The enduring hope is that these molecular biomarkers will make the transition to clinical applicability either in the direct endoscopic setting or even using non-endoscopic methods.

Targeting care in Barrett's oesophagus.

Barretts oesophagus represents the most significant risk factor for the development of oesophageal adenocarcinoma (OAC), although the majority of patients will not develop cancer. However, early detection of OAC and its precursors significantly improves outcome and underlines the importance of endoscopic surveillance programmes. Clearly there is a discrepancy between the small number of people who need to undergo surveillance because they are at significant progression risk, and the large number that do. Research is therefore now concentrated on risk stratification. Currently such stratification is currently based on clinical findings, endoscopic diagnosis and histopathological grade. Histopathology can be imperfect and is likely to require molecular confirmation of different grades, thus molecular stratification is becoming more important in this regard and p53 immunohistochemistry is already clinically useful, with other molecular biomarkers likely to prove beneficial in the future. The hope is that non-endoscopic methods, such as the Cytosponge may be able to combine molecular biomarkers with histopathology and therefore perhaps benefit a population screening as well as a surveillance programme.

Squamous cell carcinoma after radiofrequency ablation for Barrett's dysplasia.

Barrett's oesophagus (BO) is a usually indolent condition that occasionally requires endoscopic therapy. Radiofrequency ablation (RFA) is an effective endoscopic treatment for high grade dysplasia (HGD) and intramucosal cancer in BO. It has a good efficacy, durability and safety profile although complications can occur. Here we describe a case of RFA in a patient with high grade dysplasia. Although the response to treatment was initially very good with the development of neosquamous epithelium, the patient very rapidly developed a squamous cell cancer of the oesophagus confirmed on radiology, histology and immunohistochemistry. Sanger sequencing confirmed that the original HGD and the squamous cell cancer (SCC) were derived from separate clonal origins. The report highlights the fact that SCC of the oesophagus has been noted after endoscopic ablation for BO previously and suggest that ablation of BO may encourage the clonal expansion of cells carrying carcinogenic mutations once a dominant clonal population has been eradicated.

The stem cell organisation, and the proliferative and gene expression profile of Barrett's epithelium, replicates pyloric-type gastric glands.

OBJECTIVE: Barrett's oesophagus shows appearances described as 'intestinal metaplasia', in structures called 'crypts' but do not typically display crypt architecture. Here, we investigate their relationship to gastric glands. METHODS: Cell proliferation and migration within Barrett's glands was assessed by Ki67 and iododeoxyuridine (IdU) labelling. Expression of mucin core proteins (MUC), trefoil family factor (TFF) peptides and LGR5 mRNA was determined by immunohistochemistry or by in situ hybridisation, and clonality was elucidated using mitochondrial DNA (mtDNA) mutations combined with mucin histochemistry. RESULTS: Proliferation predominantly occurs in the middle of Barrett's glands, diminishing towards the surface and the base: IdU dynamics demonstrate bidirectional migration, similar to gastric glands. Distribution of MUC5AC, TFF1, MUC6 and TFF2 in Barrett's mirrors pyloric glands and is preserved in Barrett's dysplasia. MUC2-positive goblet cells are localised above the neck in Barrett's glands, and TFF3 is concentrated in the same region. LGR5 mRNA is detected in the middle of Barrett's glands suggesting a stem cell niche in this locale, similar to that in the gastric pylorus, and distinct from gastric intestinal metaplasia. Gastric and intestinal cell lineages within Barrett's glands are clonal, indicating derivation from a single stem cell. CONCLUSIONS: Barrett's shows the proliferative and stem cell architecture, and pattern of gene expression of pyloric gastric glands, maintained by stem cells showing gastric and intestinal differentiation: neutral drift may suggest that intestinal differentiation advances with time, a concept critical for the understanding of the origin and development of Barrett's oesophagus.

Clonal selection and persistence in dysplastic Barrett's esophagus and intramucosal cancers after failed radiofrequency ablation.

OBJECTIVES: Radiofrequency ablation (RFA) is used to successfully eliminate Barrett's esophagus (BE)-related dysplasia or intramucosal carcinoma and aims to cause reversion to squamous epithelium. However, in 20% of cases RFA fails to return the epithelium to squamous phenotype. Follow-up studies show a similar dysplasia recurrence rate. We hypothesize that failed RFA is due to clonally mutated epithelial populations harbored in RFA-privileged sites and that RFA can select for the mutant clonal expansion. METHODS: A longitudinal case series of 19 patients with BE and high-grade dysplasia or intramucosal carcinoma were studied. DNA was extracted from individual Barrett's glands, deep esophageal glands within mucosal resections and biopsy specimens before and after RFA. Mutations were identified by targeted sequencing of genes commonly mutated in Barrett's adenocarcinoma. RESULTS: Five patients demonstrated persistent post-RFA pathology with persistent mutations, sometimes detected in deep esophageal glands or neighboring squamous epithelium after several rounds of RFA preceded by mucosal resection. Recurrence of pathology in three other patients was characterized by de novo mutations. CONCLUSIONS: Protumorigenic mutations can be found in post-ablation squamous mucosa as well as in mutant deep esophageal glands; both are associated with dysplasia recurrence. Following RFA, non-dysplastic Barrett's epithelium can contain mutant clones that are found in a subsequent adenocarcinoma. Ablation may also drive the clonal expansion of pre-existing clones after a "bottleneck" created by the RFA. Overall, recurrence of dysplasia post RFA reflects the multicentric origins of Barrett's clones and highlights the role of clonal selection in carcinogenesis.

Crypt dysplasia in Barrett's oesophagus shows clonal identity between crypt and surface cells.

Epithelial dysplasia is an important histological diagnosis signifying the presence of pre-invasive disease, usually needing intervention. However, the specific genetic changes responsible for the induction of this phenotypic change are unknown. Moreover, recent reports indicate that the dysplastic phenotype may not be immutable: in basal crypt dysplasia (CD), unequivocal dysplastic changes are seen in the crypts in Barrett's oesophagus and other pre-invasive lesions in the gastrointestinal tract, but the upper crypts and surface epithelium associated with these dysplastic crypts show the definitive morphology of a differentiated epithelium. The genotypic relationship between CD and the differentiated surface epithelium is presently unclear. We obtained 17 examples of CD: the lower and upper crypts and surface epithelium were differentially laser-microdissected from formalin-fixed, paraffin-embedded sections and mutations were sought in tumour suppressor genes frequently associated with progression in Barrett's oesophagus. We found two patients who both showed a c. C238T mutation in the CDKN2A (CDKN2AInk4A) gene and where the precise microanatomical relationships could be discerned: this mutation was present in both the CD at the crypt base and in the upper crypt and surface epithelium. We conclude that, in CD, the dysplastic basal crypt epithelium and the upper crypt and surface epithelium show clonal CDKN2A mutations, thus showing definitively that the surface epithelium is derived from the dysplastic crypt epithelium: the dysplastic phenotype is therefore not fixed and can be reversed. The mechanism of this change is unclear but may be related to the possibility that dysplastic cells can, probably early in their progression, respond to differentiation signals. However, it is also clear that a heavy mutational burden can be borne by crypts in the gastrointestinal tract without the development of phenotypic dysplasia. We are evidently some way from understanding the plasticity and the genotypic correlates of the dysplastic phenotype.

Utilizing DNA mutations to trace epithelial cell lineages in human tissues.

Epithelial stem cells are typically multipotential and are likely the cell of origin of epithelial cancers. Tracing the expansion of a single stem cell's progeny, identifying and characterizing these cells in human tissue has proven difficult. Invasive labeling studies, which have led to much success in model organisms, are impracticable in humans. Instead, human studies must rely upon naturally occurring clonal markers: typically somatic DNA alterations that uniquely identify a population of cells with the same ancestry. In normal epithelium, nonpathogenic mitochondrial DNA mutations have proven useful. In premalignant and malignant disease, genomic DNA mutations within tumor suppressor genes or oncogenes can be used to trace the spread of mutant clones.

Field cancerization in Barrett's esophagus.

Barrett's esophagus is a columnar metaplasia conferring an increased risk of adenocarcinoma development. Evidence suggests that this increased risk is due to field cancerization - the formation of histologically undistinguishable field of clonally derived, mutant cells within the Barrett's segment. Field cancerization can occur prior to both dysplasia and invasive neoplasia and potentially provides a mechanism for the development of multifocal and metachronous tumors. In the gastrointestinal tract, mutant clones spread predominately by crypt fission; the same is likely to be true in Barrett's lesions. Epithelial interactions in the form of cooperation or competition between epithelial clones, as well as with stromal cells, may further drive clone growth. Field cancerization is a clinically relevant phenomenon, knowledge of which could influence the size of resection margins to enhance prognosis after curative surgery, as well as provide a rationale for the development of effective biomarkers for neoplasia risk in Barrett's esophagus. This may provide a foundation for streamlined surveillance programs to prevent the development of invasive tumors.

Stem cells and their implications for colorectal cancer.

The colonic crypt is home to several multipotent stem cells. These stem cells reside in a niche at the base of the crypt, which controls their behavior and maintains the stem cell's homeostasis through a variety of signaling pathways and interactions. Several attempts have been made to define markers that can identify colonic stem cells, the most useful of which is Lgr5, a Wnt target gene. Although the crypt base contains several stem cells, each colonic crypt comprises a single clone of cells. Investigators have attempted to reconcile these apparently contradictory observations by conducting research into stem cell division. The propagation of stem-cell-acquired mutations through a crypt results in a monocryptal adenoma that, through crypt fission, develops into a microadenoma. Some early adenomas become polyclonal through an as yet unknown mechanism. The discovery of subpopulations of cancer cells that can initiate tumors when implanted into mice has renewed interest in the existence of cancer stem cells, especially with regard to their implications for the use of chemotherapy. Various potential markers of cancer stem cells have been investigated, particularly CD133, but the cancer stem cell theory still has some limitations.

Refeeding hypophosphataemia is more common in enteral than parenteral feeding in adult in patients.

BACKGROUND & AIMS: Refeeding hypophosphataemia (RH) can result in sudden death. This study aimed to compare the incidence of RH between patients fed enterally and those fed parenterally. METHODS: The risk of RH in adult patients fed parenterally (PN) or nasogastrically (NG) was assessed by comparison of patient records with the UK NICE guidelines for refeeding syndrome, between December 2007 and December 2008. A fall in serum phosphate to less than 0.6 mmol/L was indicative of RH. RESULTS: Of 321 patients,92 were at risk of RH. Of these, 23 (25%) patients developed RH (p = 0.003). 18 (33%) of NG fed, 'at-risk' patients developed RH vs 5 (13%) fed parenterally (p = 0.03). Death within 7 days and RH were not associated. The sensitivity and specificity of the NICE criteria for defining patient's risk of RH was calculated: 0.76 and 0.50 respectively for NG feeding; 0.73 and 0.38 respectively for parenteral feeding. CONCLUSION: Patients fed by NG tube and deemed at risk of RH are more likely to develop RH than patients fed by PN. The higher risk with NG feeding may be due to the incretin effect from absorption of glucose. The UK guidelines lack specificity.