[Show abstract][Hide abstract] ABSTRACT: The relevance of spatial composition in the microbial changes associated with UC is unclear. We coupled luminal brush samples, mucosal biopsies and laser capture microdissection with deep sequencing of the gut microbiota to develop an integrated spatial assessment of the microbial community in controls and UC.
A total of 98 samples were sequenced to a mean depth of 31 642 reads from nine individuals, four control volunteers undergoing routine colonoscopy and five patients undergoing surgical colectomy for medically-refractory UC. Samples were retrieved at four colorectal locations, incorporating the luminal microbiota, mucus gel layer and whole mucosal biopsies.
Interpersonal variability accounted for approximately half of the total variance. Surprisingly, within individuals, asymmetric Eigenvector map analysis demonstrated differentiation between the luminal and mucus gel microbiota, in both controls and UC, with no differentiation between colorectal regions. At a taxonomic level, differentiation was evident between both cohorts, as well as between the luminal and mucosal compartments, with a small group of taxa uniquely discriminating the luminal and mucosal microbiota in colitis. There was no correlation between regional inflammation and a breakdown in this spatial differentiation or bacterial diversity.
Our study demonstrates a conserved spatial structure to the colonic microbiota, differentiating the luminal and mucosal communities, within the context of marked interpersonal variability. While elements of this structure overlap between UC and control volunteers, there are differences between the two groups, both in terms of the overall taxonomic composition and how spatial structure is ascribable to distinct taxa.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Gut 01/2015; 64(10). DOI:10.1136/gutjnl-2014-307873 · 14.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bevacizumab improves progression free survival (PFS) and overall survival (OS) in metastatic colorectal cancer patients however currently there are no biomarkers that predict response to this treatment. The aim of this study was to assess if differential protein expression can differentiate patients who respond to chemotherapy and bevacizumab, and to assess if select proteins correlate with patient survival.
Pre-treatment serum from patients with metastatic colorectal cancer (mCRC) treated with chemotherapy and bevacizumab were divided into responders and nonresponders based on their progression free survival (PFS). Serum samples underwent immunoaffinity depletion and protein expression was analysed using two-dimensional difference gel electrophoresis (2D-DIGE), followed by LC-MS/MS for protein identification. Validation on selected proteins was performed on serum and tissue samples from a larger cohort of patients using ELISA and immunohistochemistry, respectively (n = 68 and n = 95, respectively).
68 proteins were identified following LC-MS/MS analysis to be differentially expressed between the groups. Three proteins (apolipoprotein E (APOE), angiotensinogen (AGT) and vitamin D binding protein (DBP)) were selected for validation studies. Increasing APOE expression in the stroma was associated with shorter progression free survival (PFS) (p = 0.0001) and overall survival (OS) (p = 0.01), DBP expression (stroma) was associated with shorter OS (p = 0.037). Increasing APOE expression in the epithelium was associated with a longer PFS and OS, and AGT epithelial expression was associated with a longer PFS (all p < .05). Increasing serum AGT concentration was associated with shorter OS (p = 0.009).
APOE, DBP and AGT identified were associated with survival outcomes in mCRC patients treated with chemotherapy and bevacizumab.
BMC Cancer 11/2014; 14(1):887. DOI:10.1186/1471-2407-14-887 · 3.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Small bowel involvement of Clostridiumdifficile is increasingly encountered. Data on many management aspects are lacking.
To synthesis existing reports and assess the frequency, pathophysiology, outcomes, risk factors, diagnosis and management of C.difficle enteritis.
A systematic review of the literature was conducted to evaluate evidence regarding frequency, pathophysiology, risk factors, optimal diagnosis, management and outcomes for C.difficle enteritis. Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The review included original articles reporting C.difficle enteritis from January 1950 to December 2012.
C.difficle enteritis is rare but increasingly encountered. Presentation is variable and distinct predisposing factors include emergency surgery, white race and increased age. Diagnosis generally involves a sensitive but often non specific screening test for C.difficile antigens. Oral metronidazole represents first line therapy and surgery may be required for complications. Outcomes are inconsistent but may be improving.
A high index of clinical suspicion, early diagnosis and treatment are vital. Further prospective studies are needed to determine the significance of asymptomatic small bowel C.difficile infections.
The surgeon: journal of the Royal Colleges of Surgeons of Edinburgh and Ireland 10/2014; 12(5). DOI:10.1016/j.surge.2014.01.008 · 2.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: AimThere is debate about whether the traditional three-tiered grading of anal intraepithelial neoplasia (AIN) should be replaced by a more reproducible two-tiered system. In this study, we review our experience with AIN to determine the most suitable classification system. Method
We performed a retrospective review of all histological reports over a 19year period. All specimens were graded on haemataloxin and eosin appearance and those with dysplasia had immunohistochemistry for p16 and Ki67 performed. ResultsCases included 25 condyloma acuminata, 11 dysplastic cases and 24 invasive squamous cell carcinomas. On review, 18 were classified as condyloma acuminata without dysplasia. Seven had AIN I, five had AIN II and six had AIN III when using a three-tiered system. All cases classified as dysplastic (n=18) showed an increased proliferation index as measured by Ki67. p16 positivity was seen in all AIN III, two AIN II and none of the AIN I cases. Recurrence was not observed in any of the AIN I cases. Five of eleven AIN II and AIN III cases recurred or persisted at a similar, higher or lower grade. Both of the AIN II cases which recurred or persisted were p16 positive. None of the AIN II cases that were p16 negative recurred. Three of the p16-positive AIN III cases did not recur. None of the 18 AIN cases progressed to carcinoma. Conclusion
The findings support the slow progression of AIN as described in the literature. In our small series, a two-tiered system with further subclassification of the traditional AIN II group using p16 appears to be clinically useful.
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Over 5,100 colorectal cancers (CRC) are diagnosed in the United Kingdom 85 year and older age group per year but little is known of cancer progression in this group. We assessed clinical, pathological and molecular features of CRC with early and late mortality in such patients.
METHODS: Data were analysed in relation to early mortality and long-term survival in 90 consecutive patients with CRC patients aged 85 years or older in a single hospital.
RESULTS: Patients not undergoing operation, those with an ASA score of III or greater and those with advanced tumour stage were more likely to die within 30 days. Regression analysis showed that 30 day mortality was independently related to failure to undergo resection (odds ratio (O.R.), 10.0; 95% confidence interval [C.I.],1.7-58.2; p=0.01) and ASA score of III or greater (O.R. 13.0; 95% C.I.,1.4-12.6; p=0.03). All cause three and five year survival was 47% and 23% percent respectively for patients alive 30 days after diagnosis. Three and five year relative survival was 64% percent and 54%, percent respectively. Long-term outcome was independently related to tumour stage (relative risk [R.R.], 2; 95% C.I.1.3-3.1;p=0.001) presence of co-morbid diseases (R.R.,2.8; 95% C.I., 1.3-6.0;p=0.007) and lipid peroxidation status (R.R.,2.9; 95% C.I.,1.1-7.5;p=0.025).
CONCLUSIONS: An active multidisciplinary approach to the care of patients with CRC patients at the upper extreme of life is reasonable. It also seems sensible to individualise care based upon the extent of disease at diagnosis and the presence of co-morbid conditions. Further studies to examine the role of lipid peroxidation are warranted.
[Show abstract][Hide abstract] ABSTRACT: Abdominal rectopexy is used to treat full thickness rectal prolapse and obstructed defecation syndrome, with good outcomes. Use of a laparoscopic approach may reduce morbidity. The current study assessed short-term operative outcomes for patients undergoing laparoscopic or open rectopexy.
Rectopexy cases were identified from theater logs in two tertiary referral centers. Patient demographics, intra-operative details and early postoperative outcomes were examined.
There were 62 patients included over 10 years, a third of whom underwent laparoscopic rectopexy. Laparoscopy was associated with a longer operative time (195.9 versus 129.6 min, p = 0.003), but this did not affect postoperative outcomes, with no significant differences found for complication rates and length of stay between the two groups. Univariable analysis found no influence of laparoscopic approach on the likelihood of postoperative complications, and no factor achieved significance with multivariable analysis. This study included the first laparoscopic cases performed in the involved institutions, and a "learning curve" existed as seen with a decreasing operative duration per case over time (p = 0.002).
Laparoscopic rectopexy has similar short-term outcomes to open rectopexy.
Irish Journal of Medical Science 04/2014; 184(2). DOI:10.1007/s11845-014-1125-0 · 0.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose
The incidence of primary colorectal lymphoma (PCL) is rare (0.2–0.6% of large bowel malignancy). Up to one third of Non-Hodgkin's lymphoma will present with extra-nodal manifestations only. Extra-nodal lymphomas arise from tissues other than the lymph nodes and even from sites, which contain no lymphoid tissue. The incidence of Non-Hodgkin's lymphoma has increased over the past fifty years. The objective of this study was to examine our experience of PCL.
A prospectively-compiled database (1988–2012) of patients with colorectal cancer was retrospectively examined for cases of colorectal lymphoma. A retrospective chart review identified cases of PCL based on Dawson's criteria. Clinical information was obtained from case notes.
Eleven patients (0.3% of 4219 patients) were identified (6 male, 5 female). The median age at diagnosis was 63 years. Mode of presentation varied; abdominal pain, a palpable mass and per rectal bleeding being the most frequent. The caecum was the most frequently involved site (5/11). Nine patients underwent surgical management, one had chemotherapy alone and one had radiotherapy alone. All cases were non-Hodgkin's lymphoma, with diffuse large B-cell lymphoma in majority. The median event-free survival of those treated with surgery and post-operative chemotherapy was 10 months (range 5–120 months).
Primary colorectal lymphoma is rare. Management is multidisciplinary and dependent on the subtype of lymphoma. Due to the rarity of diagnosis, there is a paucity of randomised control trials. Most information published is based on individual case reports and there is, thus, no clear treatment algorithm for these cases.
The surgeon: journal of the Royal Colleges of Surgeons of Edinburgh and Ireland 03/2014; 13(3). DOI:10.1016/j.surge.2014.01.002 · 2.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To examine the association between single-nucleotide polymorphisms (SNPs) in CTGF (connective tissue growth factor) and patient outcomes after terminal ileal resection for Crohn's disease.
The primary indication for intestinal resection in Crohn's disease is fibrostenotic terminal ileal disease. CTGF is a cytokine overexpressed in the intestine of patients with Crohn's disease that influences outcomes in other disease processes.
DNA was extracted from formalin-fixed, paraffin-embedded tissue from 147 patients with Crohn's disease who had undergone terminal ileal resection between 1981 and 2009. Genotyping was performed for 4 CTGF SNPs (rs9402373, rs12526196, rs6918698, and rs9399005), which modulate nuclear factor binding and CTGF production, and a smad3 SNP (rs17293632) involved in the CTGF pathway. Patients were phenotyped using the Montreal Disease Classification.
Sixty-seven of 147 patients (45.6%) were male; the mean age at diagnosis was 30.3 ± 12.6 years and the mean follow-up duration was 8.3 ± 7.1 years. Genotype-phenotype analysis demonstrated that the rs6918698GG genotype was associated with an older age of disease onset [>40 years; 30.6% vs 13.2%; odds ratio (OR): 2.891; 95% confidence interval (CI): 1.170-7.147). The rs9402373CC genotype was positively associated with type B1 disease (50.7% vs 26.3%; OR: 2.876; 95% CI: 1.226-6.743) and negatively associated with B2 disease (37.0% vs 65.0%; OR: 0.317; 95% CI: 0.144-0.699). None of the 5 SNPs assessed influenced clinical or surgical recurrence of Crohn's disease after intestinal resection. On multivariate analysis, male sex odds ratio (OR): 0.235; 95% CI: 0.073-0.755; P = 0.015] and never having smoked tobacco (OR: 0.249; 95% CI: 0.070-0.894; P = 0.033) reduced the risk, whereas having a prior appendectomy increased the risk (OR: 5.048; 95% CI: 1.632-15.617; P = 0.005) of surgical recurrence.
These data implicate the rs6918698GG genotype with an age of disease onset of greater than 40 years in Crohn's disease whereas the rs9402373CC genotype is associated with a nonstricturing, nonpenetrating disease phenotype. CTGF SNPs do not influence the rate of recurrence after terminal ileal resection for Crohn's disease.
Annals of surgery 11/2013; 258(5):767-774. DOI:10.1097/SLA.0000000000000247 · 8.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: : The use of self-expanding metal stents as a bridge to surgery in the setting of malignant colorectal obstruction has been advocated as an acceptable alternative to emergency surgery. However, concerns about the safety of stenting have been raised following recent randomized studies.
: The aim of the current study was to compare outcomes.
: This was an observational, comparative study.
: This study was conducted at a tertiary referral center and university teaching hospital.
: Patients with malignant colonic obstruction (n = 49) treated by either emergency surgery (n = 26) or with stent placement (n = 23) as a bridge to surgery were identified and followed.
: Short-term outcomes including stoma rates and postoperative morbidity and medium-term oncological outcomes were compared based on an "intention-to-treat" analysis.
: Patients in both groups were well matched on clinicopathological parameters. Technical and clinical successful stent deployment was achieved in 91% and 83%. This did not adversely impact cancer-specific and overall survival (log rank = nonsignificant). No difference was observed in stoma rates, primary anastomosis rates, perioperative mortality rates, or reoperation rates between the 2 groups. Significantly fewer patients underwent total colectomy in the stent group in comparison with the emergency surgery group (1/23 vs 6/26: p = 0.027). There was no difference in postoperative morbidity (59% vs 66%: p = 0.09). There was a significant reduction in readmission rates in the stent group (5/26 vs 0/23: p = 0.038).
: The small sample size of this study could lead to type II error. In addition, the study was nonrandomized and demonstrated a limited length of follow-up.
: Despite a high rate of technical and clinical success in selected patients with colonic obstruction, stenting has no impact on stoma rates. Despite concerns about the rate of stent-associated perforation, stenting does not adversely impact disease progression or survival. Future comparative trials are essential to better define the role of stenting in this setting and to ensure that we are not using costly technology to create an elective operative situation without concomitant patient benefits.
Diseases of the Colon & Rectum 04/2013; 56(4):433-40. DOI:10.1097/DCR.0b013e3182760506 · 3.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
This study evaluated the clinicopathological features and survival rates of patients with inflammatory bowel disease who developed colorectal cancer (CRC).
A retrospective review was performed on a prospectively maintained institutional database (1981-2011) to identify patients with inflammatory bowel disease who developed CRC. Clinicopathological parameters, management and outcomes were analysed.
A total of 2,843 patients with inflammatory bowel disease were identified. One thousand six hundred and forty-two had ulcerative colitis (UC) and 1,201 had Crohn's disease (CD). Following exclusion criteria, there were 29 patients with biopsy-proven colorectal carcinoma, 22 of whom had UC and 7 had CD. Twenty-six patients had a preoperative diagnosis of malignancy/dysplasia; 16 of these were diagnosed at surveillance endoscopy. Nodal/distant metastasis was identified at presentation in 47 and 71 % of the UC and CD group, respectively. Operative morbidity for UC and CD was 33 and 17 %, respectively. Despite the less favourable operative outcomes following surgery management of UC-related CRC, overall 5-year survival was significantly better in the UC group compared to the CD group (41 vs. 29 %; p = 0.04) reflecting the difference in stage at presentation between the two groups.
Patients who undergo surgery for UC-related CRC have less favourable short-term outcomes but present at a less advanced stage and have a more favourable long-term prognosis than similar patients with CRC and CD.
Techniques in Coloproctology 02/2013; 18(1). DOI:10.1007/s10151-013-0981-3 · 2.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (http://www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length. Copyright (c) 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
British Journal of Surgery 11/2012; 99(11):1601-2. DOI:10.1002/bjs.8947 · 5.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Defects in DNA repair pathways have been linked with colorectal cancer (CRC). Adjuvant radiotherapy has become commonplace in the treatment of rectal cancer however it is associated with a higher rate of second cancer formation. It is known that radiation results in DNA damage directly or indirectly by radiation-induced bystander effect (RIBE) by causing double-strand breaks (DSBs). The majority of work in RIBE has been performed in cell lines and limited studies have been in or ex vivo.
The first study aim was to examine by immunohistochemistry, levels of DSB (expression of the protein MRE11) in normal colonic tissue outside the irradiated field post neo-adjuvant radiotherapy (group 1). These levels were compared to (a) irradiated tumour tissue post neo-adjuvant radiation within the same group, (b) a CRC patient group (group 2) who had not undergone neo-adjuvant radiotherapy and (c) a non-cancer patient group (group 3). The second aim was to determine if MRE11 expression levels were related to survival or radio-sensitivity post neo-adjuvant radiotherapy.
There was a highly significant increase in MRE 11 expression in group 1 versus groups 2 and 3 (p < 0.001). There was no association between MRE11 levels and survival or radio-sensitivity.
Our findings show radiotherapy causes DSBs at significantly higher levels in normal colonic mucosa of patients post neo-adjuvant treatment which may represent RIBE. If this damage remains unrepaired, increased levels of genomic instability may contribute to the higher occurrence of second cancers in patients treated post neo-adjuvant radiotherapy.
Journal of Gastrointestinal Cancer 10/2012; 44(1). DOI:10.1007/s12029-012-9442-x · 0.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Local excision of rectal cancer after neoadjuvant chemoradiotherapy (CRT) has been proposed as an alternative to radical surgery in selected patients. However, little is known about the significance of the morphological and histological features of residual tumour.
Patients who had undergone CRT at the authors' institution between 1997 and 2010 were identified. Multiple features were assessed as putative markers of pathological response. These included: gross residual disease, diameter of residual mucosal abnormalities, tumour differentiation, presence of lymphovascular/perineural invasion and lymph node ratio.
Data from 220 of 276 patients were suitable for analysis. Diameter of residual mucosal abnormalities correlated strongly with pathological tumour category after CRT (ypT) (P < 0·001). Forty of 42 tumours downstaged to ypT0/1 had residual mucosal abnormalities of 2·99 cm or less after CRT. Importantly, 19 of 31 patients with a complete pathological response had evidence of a residual mucosal abnormality consistent with an incomplete clinical response. The ypT category was associated with both pathological node status after CRT (P < 0·001) and lymph node ratio (P < 0·001). Positive nodes were found in only one of 42 patients downstaged to ypT0/1. The risk of nodal metastases was associated with poor differentiation (P = 0·027) and lymphovascular invasion (P < 0·001).
In this series, the majority of patients with a complete pathological response did not have a complete clinical response. In tumours downstaged to ypT0/1 after CRT, residual mucosal abnormalities were predominantly small and had a 2 per cent risk of positive nodes, thus potentially facilitating transanal excision. The presence of adverse histological characteristics risk stratified tumours for nodal metastases.
British Journal of Surgery 07/2012; 99(7):993-1001. DOI:10.1002/bjs.8700 · 5.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Immune suppression is a feature of colorectal cancer, however the underlying
mechanisms by which colorectal cancer evades the host immune response, allowing the
establishment of primary tumours and metastasis remains unknown. Dendritic Cells (DC)
are a key player in the immune response against tumours as they have the potential to
stimulate a potent cytotoxic immune response. CD4+ T cells play a central role in cell
mediated immunity and may inhibit anti-tumor immune responses. Aim: To determine if
systemic and local immune suppression in colorectal cancer patients increases with advancing
disease. Materials and Methods: Serum from patients with colorectal cancer (20 patients per
stage) was collected and levels of IL10, IL12, IL27 and IFN-γ were measured. Peripheralblood DC subsets were assessed by flow cytometry on whole blood. Myeloid DCs were
defined as Lin1-HLA-DR+CD1c+ cells and plasmacytoid DCs were defined as Lin1-HLADR+BDCA-2+.
Explant tumour tissue obtained from patients with different stages of CRC
progression was cultured In Vitro for 3 days to generate tumour condition media (TCM).
Monocyte derived DCs (MDDCs) and CD4+ T cells were generated from healthy donors.
The immature MDDCs or T cells were pre-treated with TCM andstimulated with LPS or
anti-CD3/CD28. The cells were assessed for expression of maturation markers by flow
cytometry and secretion of IL-10 and IL-12p70 measured by ELISA. T cell proliferation was
assessed by CFSE dye dilution and levels of IFN-γ and IL-10 assessed by ELISA. RESULTS
Serum levels of IFN-γ were reduced in stage IV patients compared to either Stage 2 or 3
(p<0.05). IL-10 levels were increased in stage IV (P<0.0001) compared to stage 1-3. No
difference was observed in Il-12 and IL-27 levels. Levels of pDCs were significantly lower
in colorectal cancer patients compared to controls (p=0.0496DCs pre-treated with TCM
from all stages of colorectal cancer failed to upregulate maturation markers effectively in
response to LPS and secreted increased levels of IL-10. IL-12p70 secretion by DCs stimulated
with LPS pre-treated with TCM from all stages of CRC was significantly inhibited p<.0.05.
T cell secretion of IFN-gamma was suppressed by TCM of from all stages while IL-10
secretion was enhanced. Conclusion: The local tumour milieu suppresses T cell and DC
activation in all stages of colorectal cancer, however dysregulation of systemic cytokine levels
(increased IL-10 with a concomitant decrease in IFN-gamma) occurs at stage III and IV
cancers but not earlier stages of disease. Our continuing studies of the effect of the tumour
microenvironment on immune function will lead to a greater understanding of the mechanisms
of tumour host immune response evasion and will facilitate improved targeted therapy
in the treatment of colorectal cancer.