[Show abstract][Hide abstract] ABSTRACT: Lynch syndrome is one of the most common cancer susceptibility syndromes. Individuals with Lynch syndrome have a 50%-70% lifetime risk of colorectal cancer, 40%-60% risk of endometrial cancer, and increased risks of several other malignancies. It is caused by germline mutations in the DNA mismatch repair genes MLH1, MSH2, MSH6 or PMS2. In a subset of patients, Lynch syndrome is caused by 3' end deletions of the EPCAM gene, which can lead to epigenetic silencing of the closely linked MSH2. Relying solely on age and family history based criteria inaccurately identifies eligibility for Lynch syndrome screening or testing in 25%-70% of cases. There has been a steady increase in Lynch syndrome tumor screening programs since 2000 and institutions are rapidly adopting a universal screening approach to identify the patients that would benefit from genetic counseling and germline testing. These include microsatellite instability testing and/or immunohistochemical testing to identify tumor mismatch repair deficiencies. However, universal screening is not standard across institutions. Furthermore, variation exists regarding the optimum method for tracking and disclosing results. In this review, we summarize traditional screening criteria for Lynch syndrome, and discuss universal screening methods. International guidelines are necessary to standardize Lynch syndrome high-risk clinics.
[Show abstract][Hide abstract] ABSTRACT: Surgery remains the mainstay of treatment for malignant melanoma. Despite previous studies examining the surgical interval (SI) between the diagnostic excision biopsy (DEB) and definitive surgical management there remains few guidelines regarding an optimal time interval. The aim of this study was to determine the SI between DEB and definitive surgery and elucidate factors associated with delays in management of malignant melanoma.
Irish Journal of Medical Science 06/2014; · 0.51 Impact Factor
[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.
Journal of Geriatric Oncology 05/2014; · 1.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Many aspects of microscopic colitis remain poorly understood. Our aim was to report a single centre experience with this condition.
Two hundred and twenty-two patients (52 male, 170 female; median age 64 years; range 32-90) diagnosed between 1993 and 2010 were studied. Medical notes were reviewed, and data on age, gender, clinical features, history of autoimmune diseases, medication use, cigarette smoking, histology and outcome were collected.
There were 99 cases of lymphocytic and 123 of collagenous colitis. Diarrhoea was almost invariably present (98 %) while abdominal pain (24 %), weight loss (10 %), faecal incontinence (8 %) and blood PR (5 %) were also described. Twenty-eight percent had concomitant autoimmune diseases, most commonly coeliac disease. Patients were taking a variety of medications at diagnosis thought to be associated with microscopic colitis including NSAIDs (22 %), aspirin (19 %), statins (15 %), proton pump inhibitors (19 %) and SSRIs (10 %) at diagnosis. Prior to the widespread use of budesonide in our institution, 33 % of patients required two or more medications during therapy compared to 15 % following the introduction of budesonide (p = 0.001). Thirty-eight percent of patients achieved spontaneous remission with either no treatment or simple anti-diarrhoeals. Using a multivariate model, the only factor associated with spontaneous remission was male gender (RR 1.9; 95 % CI 1.0-3.6; p = 0.04). Two patients had refractory microscopic colitis; one required a colectomy while a more recent case has responded to anti-TNFα therapy.
Microscopic colitis is predominantly a benign and self-limiting disorder. The introduction of budesonide has revolutionised treatment of this lesser studied inflammatory bowel disease.
International Journal of Colorectal Disease 04/2014; · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Locally advanced rectal cancer (LARC: T3/4 and/or node-positive) is treated with preoperative/neoadjuvant chemoradiotherapy (CRT), but responses are not uniform. The phosphatidylinositol 3-kinase (PI3K), MAP kinase (MAPK), and related pathways are implicated in rectal cancer tumorigenesis. Here, we investigated the association between genetic mutations in these pathways and LARC clinical outcomes.
We genotyped 234 potentially clinically relevant nonsynonymous mutations in 33 PI3K and MAPK pathway-related genes, including PIK3CA, PIK3R1, AKT, STK11, KRAS, BRAF, MEK, CTNNB1, EGFR, MET, and NRAS, using the Sequenom platform. DNA samples were extracted from pretreatment LARC biopsy samples taken from 201 patients who were then treated with long-course neoadjuvant CRT followed by surgical resection.
Sixty-two mutations were detected in 15 genes, with the highest frequencies occurring in KRAS (47 %), PIK3CA (14 %), STK11 (6.5 %), and CTNNB1 (6 %). Mutations were detected in BRAF, NRAS, AKT1, PIK3R1, EGFR, GNAS, MEK1, PDGFRA, ALK, and TNK2, but at frequencies of <5 %. As expected, a pathologic complete response (pCR) was associated with improved 5-year recurrence-free survival (RFS; hazard ratio, 0.074; 95 % CI 0.01-0.54; p = 0.001). Mutations in PI3K pathway-related genes (odds ratio, 5.146; 95 % CI 1.17-22.58; p = 0.030), but not MAPK pathway-related genes (p = 0.911), were associated with absence of pCR after neoadjuvant CRT. In contrast, in patients who did not achieve pCR, mutations in PI3K pathway-related genes were not associated with recurrence-free survival (p = 0.987). However, in these patients, codon 12 (G12D/G12 V/G12S) and 13 mutations in KRAS were associated with poor recurrence-free survival (hazard ratio, 1.579; 95 % confidence ratio, 1.00-2.48; p = 0.048).
Mutations in kinase signaling pathways modulate treatment responsiveness and clinical outcomes in LARC and may constitute rational targets for novel therapies.
Annals of Surgical Oncology 04/2014; · 4.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this survey was to ascertain reporting habits of pathologists towards sessile serrated adenomas/polyps (SSA/P).
A questionnaire designed to highlight diagnostic criteria, approach and clinical implications of SSA/P was circulated electronically to 45 pathologists in the UK and North America.
Forty-three of 45 pathologists agreed to participate. The vast majority (88%) had a special interest in gastrointestinal (GI) pathology, had great exposure to GI polyps in general with 40% diagnosing SSA/P at least once a week if not more, abnormal architecture was thought by all participants to be histologically diagnostic, and 11% would make the diagnosis if a single diagnostic histological feature was present in one crypt only, while a further 19% would diagnose SSA/P in one crypt if more than one diagnostic feature was present. The vast majority agreed that deeper sections were useful and 88% did not feel proliferation markers were useful. More than one-third did not know whether, or did not feel that, their clinicians were aware of the implications of SSA/P.
98% of pathologists surveyed are aware that SSA/P is a precursor lesion to colorectal cancer, the majority agree on diagnostic criteria, and a significant number feel that there needs to be greater communication and awareness among pathologists and gastroenterologists about SSA/P.
Journal of clinical pathology 01/2014; · 2.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The colonic mucus gel layer is composed of mucins that may be sulphated or sialyated. Sulphated mucins predominate in health while in ulcerative colitis(UC) sulphation is reduced. These differences result directly from inflammatory events. It may also be hypothesised that they arise in part from alterations in the colonic microbiota, particularly changes in the burden of sulphated mucin metabolising species such as desulfovibrio(DSV). The aim of this study was to correlate colonic mucin chemotypes and inflammatory scores in health and UC and relate these changes to changes in DSV colonisation of colonic crypts.
Paired colonic biopsies from 34 healthy controls (HC) and 19 patients with active UC were collected for the purpose of parallel histological and microbiological assessment. High-Iron Diamine and Alcian-Blue staining and H&E staining of mucosal biopsy specimens were used to assess histological changes within the clinical spectrum of UC. Quantitative Real-Time PCR analysis was employed to determine the total and DSV copy number within the colonic crypts.
Compared with HC, mucin chemotype in UC was less sulphated and inversely correlated with the degree of mucosal inflammation. A weak but significant negative correlation was found between abundance of sulphated mucins and DSV burden.
Mucin composition strongly correlates with the degree of mucosal inflammation, and to a lesser extent with DSV burden. These data suggest that mucin chemotype and DSV burden are linked phenomena and highlight the need to consider changes in mucin chemotype in the setting of microbial dysbiosis occurring within the colitic colon. This article is protected by copyright. All rights reserved.
[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. · 7.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Tumor budding is an increasingly important prognostic feature for pathologists to recognize. The aim of this study was to correlate intra-tumoral budding in pre-treatment rectal cancer biopsies with pathological response to neoadjuvant chemoradiotherapy and with long-term outcome. Data from a prospectively maintained database were acquired from patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy. Pre-treatment rectal biopsies were retrospectively reviewed for evidence of intra-tumoral budding. Multivariate logistic regression was used to identify factors contributing to cancer-specific death, expressed as hazard ratios with 95% confidence intervals. Of the 185 patients with locally advanced rectal cancer, 89 patients met the eligibility criteria, of whom 18 (20%) exhibited budding in a pre-treatment tumor biopsy. Intra-tumoral budding predicted a poor pathological response to neoadjuvant chemoradiotherapy (higher ypT stage, P=0.032; lymph node involvement, P=0.018; lymphovascular invasion, P=0.004; and residual poorly differentiated tumors, P=0.005). No patient with intra-tumoral budding exhibited a tumor regression grade 1 or complete pathological response, providing a 100% specificity and positive predictive value for non-response to neoadjuvant chemoradiotherapy. Intra-tumoral budding was associated with a lower disease-free 5-year survival rate (33 vs 78%, P<0.001), cancer-specific 5-year survival rate (61 vs 87%, P=0.021) and predicted cancer-specific death (hazard ratio 3.51, 95% confidence interval 1.03-11.93, P=0.040). Intra-tumoral budding at diagnosis of rectal cancer identifies those who will poorly respond to neoadjuvant chemoradiotherapy and those with a poor prognosis.Modern Pathology advance online publication, 26 July 2013; doi:10.1038/modpathol.2013.124.
[Show abstract][Hide abstract] ABSTRACT: Reprogramming of cellular metabolism is an emerging hallmark of neoplastic transformation. However, it is not known how the expression of metabolic genes in tumors differs from that in normal tissues, or whether different tumor types exhibit similar metabolic changes. Here we compare expression patterns of metabolic genes across 22 diverse types of human tumors. Overall, the metabolic gene expression program in tumors is similar to that in the corresponding normal tissues. Although expression changes of some metabolic pathways (e.g., upregulation of nucleotide biosynthesis and glycolysis) are frequently observed across tumors, expression changes of other pathways (e.g., oxidative phosphorylation) are very heterogeneous. Our analysis also suggests that the expression changes of some metabolic genes (e.g., isocitrate dehydrogenase and fumarate hydratase) may enhance or mimic the effects of recurrent mutations in tumors. On the level of individual biochemical reactions, many hundreds of metabolic isoenzymes show significant and tumor-specific expression changes. These isoenzymes are potential targets for anticancer therapy.
[Show abstract][Hide abstract] ABSTRACT: According to the international guidelines, a multidisciplinary approach is currently advised for the optimal care of patients with a gastroenteropancreatic neuroendocrine tumor (GEP NET). In our institution (tertiary care center), a systematic multidisciplinary approach was established in May 2007. In this study, we have aimed to assess the initial impact of establishing a systematic multidisciplinary approach to the management of GEP NET patients. We have collected and compared the biochemical, imaging, and pathological data and the therapeutic strategies in GEP NET patients diagnosed, treated, or followed-up from January 1993 to April 2007 versus GEP NET patients attending our institution after the multidisciplinary approach starting, from May 2007 to October 2008. Data of 91 patients before and 42 patients after the establishment of the multidisciplinary approach (total: 133 consecutive GEP NET patients) have been finally collected and analyzed. Before the establishment of the multidisciplinary approach, a lack of consistency in the biochemical, imaging, and pathological findings before treatment initiation as well as during follow-up of GEP NET patients was identified. These inconsistencies have been reduced by the systematic multidisciplinary approach. In addition, the therapeutic management of GEP NET patients has been altered by the multidisciplinary approach and became more consistent with recommended guidelines. We think that a systematic multidisciplinary approach significantly impacts on GEP NET patient care and should be established in all centers dealing with these tumors.
[Show abstract][Hide abstract] ABSTRACT: We report a case of Castleman's Disease (CD), hyaline vascular subtype involving the biliary tract with obstruction. A 43 year old man presented with a 5 week history of abdominal and back pain with biliary obstructive symptoms. He was jaundiced with persistently high LFTs. Radiological investigation revealed a stricture in the extrahepatic biliary tract. The clinical impression at the time was of sclerosing cholangitis with bile duct cholangiocarcinoma. A Whipple's procedure was performed. Histology and immunohistochemistry supported the histologic diagnosis of CD of hyaline vascular subtype. There was no evidence of disease elsewhere and the patient was disease free after a 6 year follow-up. Our case describes the hyaline vascular subtype of CD, a relatively rare disease occurring in a previously undescribed location.
Irish medical journal 03/2013; 106(3):86. · 0.51 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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; · 1.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There is controversy regarding the use of adjuvant therapy in patients with Dukes' B colorectal cancer (CRC). New markers, identifying high-risk Dukes' B patients, are needed. Here, we examine the utility of Raf kinase inhibitor protein (RKIP) as such a marker and promoter methylation as a mechanism of RKIP down-regulation.
We used a tissue microarray of 220 patients with Dukes' B CRC to examine the effect of RKIP expression on survival. Pyrosequencing was used to assess RKIP promoter methylation status.RKIP expression correlated inversely with disease-specific survival in this cohort. In multivariate analysis, RKIP was found to be an independent prognostic indicator, along with peritoneal invasion and lymphovascular invasion (LVI). RKIP promoter hypermethylation was seen in only one of 29 tumours analysed by pyrosequencing.
Raf kinase inhibitor protein, peritoneal invasion and LVI provide independent prognostic information in this cohort of Dukes' B CRC patients.This demonstrates the potential utility of RKIP in identifying 'high-risk' Dukes' B patients. It is this high-risk group which is most likely to benefit from close postoperative monitoring and may derive the most benefit from adjuvant therapy.
[Show abstract][Hide abstract] ABSTRACT: The aims of this study were to develop techniques for spatial microbial assessment in humans and to establish colonic luminal and mucosal spatial ecology, encompassing longitudinal and cross-sectional axes.
A microbiological protected specimen brush was used in conjunction with a biopsy forceps to sample the colon in nine healthy volunteers undergoing colonoscopy. Terminal Restriction Fragment Length Polymorphism analysis was used to determine the major variables in the spatial organization of the colonic microbiota.
Protected Specimen Brush sampling retrieved region-specific, uncontaminated samples that were enriched for bacterial DNA and depleted in human DNA when compared to biopsy samples. Terminal Restriction Fragment Length Polymorphism analysis revealed a segmentation of bacterial communities between the luminal brush and biopsy-associated ecological niches with little variability across the longitudinal axis of the colon and reduced diversity in brush samples.
These results support the concept of a microbiota with little longitudinal variability but with some degree of segregation between luminal and mucosal communities.
PLoS ONE 01/2013; 8(11):e78835. · 3.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BRAF is an oncogene encoding a serine-threonine protein kinase involved in the MAPK signalling cascade. BRAF acts as direct effector of RAS and through the activation of MEK, promotes tumour growth and survival. Approximately, 8% of cancers carry a BRAF mutation. However, the prevalence of this mutation varies significantly across different tumour types. There has been increasing interest in the specific role of BRAF mutations in cancer growth and progression over the last few years, especially since the clinical introduction of therapeutic BRAF inhibitors. In this paper we review the published literature on the role of BRAF mutations in melanoma and colorectal cancer, focusing on similarities and differences of BRAF mutations with respect to frequency, demographics, risk factors, mutation-associated clinico-pathologic and molecular features and clinical implications between these two diseases.
Critical reviews in oncology/hematology 12/2012; · 5.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: We report the case of a 21 year old female with underlying facial lipodystrophy who presented with left lower abdominal pain, weight gain and altered bowel habit. PRESENTATION OF CASE: Subsequent investigation showed a large (21cm×18cm×8cm) intraabdominal mass. At laparotomy, it was completely excised and was seen to arise from the transverse mesocolon and following histology revealed it to be mesenteric lipodystrophy. DISCUSSION: Mesenteric lipodystrophy is a rare clinical entity, and part of a spectrum of disorders of sclerosing mesenteritis. This is the first reported case in a patient with pre-existing facial lipodystrophy. CONCLUSION: Herein we describe a case of mesenteric lipodystrophy, discuss its management and review of the literature.
International journal of surgery case reports. 12/2012; 4(2):232-234.
[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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
[Show abstract][Hide abstract] ABSTRACT: Puppa G, Senore C, Sheahan K, Vieth M, Lugli A, Zlobec I, Pecori S, Wang L M, Langner C, Mitomi H, Nakamura T, Watanabe M, Ueno H, Chasle J, Conley S A, Herlin P, Lauwers G Y & Risio M (2012) Histopathology Diagnostic reproducibility of tumour budding in colorectal cancer: a multicentre, multinational study using virtual microscopy Aims: Despite the established prognostic relevance of tumour budding in colorectal cancer, the reproducibility of the methods reported for its assessment has not yet been determined, limiting its use and reporting in routine pathology practice. Methods and results: A morphometric system within telepathology was devised to evaluate the reproducibility of the various methods published for the assessment of tumour budding in colorectal cancer. Five methods were selected to evaluate the diagnostic reproducibility among 10 investigators, using haematoxylin and eosin (H&E) and AE1-3 cytokeratin-immunostained, whole-slide digital scans from 50 pT1-pT4 colorectal cancers. The overall interobserver agreement was fair for all methods, and increased to moderate for pT1 cancers. The intraobserver agreement was also fair for all methods and moderate for pT1 cancers. Agreement was dependent on the participants' experience with tumour budding reporting and performance time. Cytokeratin immunohistochemistry detected a higher percentage of tumour budding-positive cases with all methods compared to H&E-stained slides, but did not influence agreement levels. Conclusions: An overall fair level of diagnostic agreement for tumour budding in colorectal cancer was demonstrated, which was significantly higher in early cancer and among experienced gastrointestinal pathologists. Cytokeratin immunostaining facilitated detection of budding cancer cells, but did not result in improved interobserver agreement.