Early detection and follow-up of colorectal neoplasia based on faecal volatile organic compounds

AIM

Early detection and removal of colorectal cancer (CRC) and advanced adenomas (AAs) decreases the incidence of and mortality from the disease. We aimed to evaluate the potential of faecal volatile organic compounds (VOCs) for detection and follow-up of colorectal adenoma using advanced electronic nose technology.

METHOD

This was a prospective multi-centre case-control cohort including two district hospitals and one tertiary referral hospital. Patients undergoing colonoscopy were instructed to collect a faecal sample prior to bowel cleansing and were included in the study when CRC, AAs, large adenomas (LAs; 0.5-1.0 cm), small adenomas (SAs; 0.1-0.5 cm) or no endoscopic abnormalities (controls) were observed. Patients undergoing polypectomy and controls were asked for a second sample after 3 months. Faecal VOCs were measured with gas chromatography-ion mobility spectrometry. Random forest, support vector machine, Gaussian process and neural net classification were used to evaluate accuracy.

RESULTS

In total, 14 patients with CRC, 64 with AAs, 69 with LAs, 127 with SAs and 227 controls were included. A second sample was collected from 32 polypectomy patients and 32 controls. Faecal VOCs discriminated CRC and adenomas from control [AUC (95% CI): CRC vs control 0.96 (0.89-1); AA vs control 0.96 (0.93-1); LA vs control 0.96 (0.92-0.99); SA vs control 0.96 (0.94-0.99)]. There were no significant differences between CRC and adenoma groups. Patients with adenomas and controls were discriminated prior to polypectomy, whereas 3 months after polypectomy VOC profiles were similar [T0 adenoma vs control 0.98 (0.95-1); T1 adenoma vs control 0.55 (0.40-0.69)].

CONCLUSIONS

Faecal VOC profiles may be useful for early detection of CRC and adenomas and the timing of polyp surveillance as polypectomy led to a normalization of the VOC profile.

Volume of surgery for benign colorectal polyps in the last 11 years

BACKGROUND AND AIMS

Traditionally large, complex colorectal polyps were managed by surgical resection (SR), and in recent years endoscopic resection (ER) has progressed significantly. However, to what extent ER has replaced SR remains largely unknown. We performed a multicenter retrospective cohort study to assess the volume and volume changes of SR for benign colorectal polyps over the past decade.

METHODS

Patients who underwent SR for a benign colorectal polyp in the Netherlands between 2005 and 2015 were selected from the prospective nationwide Dutch Pathology Registry (PALGA database). Clinical characteristics were obtained from the charts of patients who underwent SR in the province of Noord-Holland.

RESULTS

A total of 5937 patients were treated with SR for a colorectal polyp and the absolute (454-739 per year) and relative volumes (0.20%-0.37% per colonoscopy per year) of SR remained stable. In the province of Noord-Holland, 928 patients (15.6%) underwent SR. In these patients, submucosal lifting and ER were attempted in 19.9% (n = 175) and 15.0% (n = 134). After 2010, patients were more likely to undergo lifting (27.7% vs 11.4%, P < .001) and ER attempts (18.8% vs 10.9%, P = .001) before definitive SR. Twenty-two patients (2.4%) had been referred to another endoscopy clinic.

CONCLUSIONS

SR for large, complex colorectal polyps is still frequently performed and has remained stable. A small percentage of patients underwent ER attempts before SR, and referral for an additional ER attempt only occurred in a minority of cases. To increase ER attempts, implementation of a regional multidisciplinary referral network should be considered.

Adenoma detection with Endocuff colonoscopy versus conventional colonoscopy: a multicentre randomised controlled trial

BACKGROUND AND AIMS

Colonoscopy is the current reference standard for the detection of colorectal neoplasia, but nevertheless adenomas remain undetected. The Endocuff, an endoscopic cap with plastic projections, may improve colonic visualisation and adenoma detection. The aim of this study was to compare the mean number of adenomas per patient (MAP) and the adenoma detection rate (ADR) between Endocuff-assisted colonoscopy (EAC) and conventional colonoscopy (CC).

METHODS

We performed a multicentre, randomised controlled trial in five hospitals and included fecal immonochemical test (FIT)-positive screening participants as well as symptomatic patients (>45 years). Consenting patients were randomised 1:1 to EAC or CC. All colonoscopies were performed by experienced colonoscopists (≥500 colonoscopies) who were trained in EAC. All colonoscopy quality indicators were prospectively recorded.

FINDINGS

Of the 1063 included patients (52% male, median age 65 years), 530 were allocated to EAC and 533 to CC. More adenomas were detected with EAC, 722 vs 621, but the gain in MAP was not significant: on average 1.36 per patient in the EAC group versus 1.17 in the CC group (p=0.08). In a per-protocol analysis, the gain was 1.44 vs 1.19 (p=0.02), respectively. In the EAC group, 275 patients (52%) had one or more adenomas detected versus 278 in the CC group (52%; p=0.92). For advanced adenomas these numbers were 109 (21%) vs 117 (22%). The adjusted caecal intubation rate was lower with EAC (94% vs 99%; p<0.001), however when allowing crossover from EAC to CC, they were similar in both groups (98% vs 99%; p value=0.25).

INTERPRETATION

Though more adenomas are detected with EAC, the routine use of Endocuff does not translate in a higher number of patients with one or more adenomas detected. Whether increased detection ultimately results in a lower rate of interval carcinomas is not yet known.

TRIAL REGISTRATION NUMBER

http://www.trialregister.nl Dutch Trial Register: NTR3962.

Risk of malignant lymphoma in patients with inflammatory bowel diseases: a Dutch nationwide study

BACKGROUND

Immune suppressant medications such as thiopurines and anti-tumor necrosis factor agents are important for maintaining disease control in most patients with inflammatory bowel diseases (IBDs); however, their use has been associated with the development of malignant lymphoma. The purpose of this Dutch nationwide study was to estimate the relative risk of malignant lymphoma in IBD patients.

METHODS

IBD patients who developed a lymphoma between 1997 and 2004 were identified using the Dutch National Database of PALGA. Data from confirmed cases were collected from individual hospitals, including data on Epstein-Barr virus (EBV). The age-adjusted 8-year incidence of malignant lymphoma in the Netherlands was retrieved from the Central Bureau of Statistics.

RESULTS

Forty-two hospitals were visited and 285 matches evaluated in the total cohort of 17,834 IBD patients. Forty-four lymphomas were observed, resulting in a relative risk of 1.27 (95% confidence interval [CI]: 0.92-1.68). Only 19 of 44 patients (43%) were exposed to azathioprine/6-mercaptopurine (AZA/6-MP). Remarkably, 92% of patients (11/12) with EBV-positive lymphoma used AZA/6-MP, in contrast to only 19% patients (4/21) with EBV-negative lymphoma, suggesting a strong relation between EBV-positive lymphoma and thiopurine use.

CONCLUSIONS

This nationwide study does not suggest a significant overall increased risk for lymphoma in IBD patients. A distinct correlation between EBV-positive lymphoma and AZA/6-MP use was observed.

Fish oil for induction of remission in ulcerative colitis

BACKGROUND

Fish oil supplements, which are rich in n-3 fatty acids, may reduce inflammation, decrease the need for anti-inflammatory drugs, and promote normal weight gain in people with ulcerative colitis.

OBJECTIVES

This review evaluates the efficacy of fish oil for induction of remission in ulcerative colitis using all available randomised controlled trials.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED, EMBASE, CINAHL, the database of ongoing trials and the reference lists of all publications of included or excluded trials were searched.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials with active ulcerative colitis patients who were treated with fish oil.

DATA COLLECTION AND ANALYSIS

The reviewers performed study selection, assessment of methodological quality by using different approaches: including Cochrane assessment of allocation concealment and Jadad quality assessment score. Data extraction forms were used by the two reviewers to extract the data independently. Authors were contacted for additional information.

MAIN RESULTS

Six studies were included. Three were of cross-over design and three were of parallel design. No data were pooled for analysis due to differences in outcomes and methodology among the included studies. One small study shows a positive benefit for induction of remission (RR 19.00; 95% CI 1.27 to 284.24). Some of the other included studies show some positive benefits for secondary outcomes. However, these results need to be interpreted with caution due to small study size and poor study quality.

AUTHORS' CONCLUSIONS

The current data does not allow for a definitive conclusion regarding the efficacy of fish oil. There is no adequate information to make recommendations for clinical practice. More research is required.

[Pneumocystis pneumonia during infliximab treatment for active Crohn's colitis]

A 51-year-old man with Crohn's disease for 22 years presented with a dry cough, dyspnoea, fever and diarrhoea. He had steroid-resistant Crohn's disease. Because of nausea complaints, azathioprine was switched to methotrexate with concomitant infliximab induction therapy. During infliximab therapy, symptoms occurred for which the patient was hospitalised and Pneumocystis pneumonia (PCP) was diagnosed by examination of bronchoalveolar lavage fluid; it was successfully treated with co-trimoxazole and prednisolone. The exacerbation of the Crohn's colitis diminished. This is the first Dutch case history of PCP during combination therapy with prednisolone, methotrexate and infliximab. Infliximab treatment has been associated with an increased risk for infectious complications. For patients with Crohn's disease, one should consider giving PCP prophylaxis for the duration of lymphocytopenia on an individual basis, weighing the adverse effects ofco-trimoxazole against the risk of PCP. A CD4-cell count < 0.2 x 10(9)/l or a lymphocyte count < 0.6 x 10(9)/l may be used as a guide.

Fine mapping of the chromosome 3p susceptibility locus in inflammatory bowel disease

BACKGROUND AND AIMS

Genetic predisposition for inflammatory bowel disease (IBD) has been demonstrated by epidemiological and genetic linkage studies. Genetic linkage of IBD to chromosome 3 has been observed previously. A high density analysis of chromosome 3p was performed to confirm prior linkages and elucidate potential genetic associations.

METHODS

Forty three microsatellite markers on chromosome 3 were genotyped in 353 affected sibling pairs of North European Caucasian extraction (average marker density 2 cM in the linkage interval). Marker order was defined by genetic and radiation hybrid techniques.

RESULTS

The maximum single point logarithm of odds (LOD) score was observed for Crohn's disease at D3S3591. Peak multipoint LOD scores of 1.65 and 1.40 for the IBD phenotype were observed near D3S1304 (distal 3p) and near D3S1283 in the linkage region previously reported. Crohn's disease contributed predominantly to the linkage. The transmission disequilibrium test showed significant evidence of association (p=0.009) between allele 4 of D3S1076 and the IBD phenotype (51 transmitted v 28 non-transmitted). Two known polymorphisms in the CCR2 and CCR5 genes were analysed, neither of which showed significant association with IBD. Additional haplotype associations were observed in the vicinity of D3S1076.

CONCLUSIONS

This study provides confirmatory linkage evidence for an IBD susceptibility locus on chromosome 3p and suggests that CCR2 and CCR5 are unlikely to be major susceptibility loci for IBD. The association findings in this region warrant further investigation.

A genomewide analysis provides evidence for novel linkages in inflammatory bowel disease in a large European cohort

Inflammatory bowel disease (IBD) is characterized by a chronic relapsing intestinal inflammation, typically starting in early adulthood. IBD is subdivided into two subtypes, on the basis of clinical and histologic features: Crohn disease and ulcerative colitis (UC). Previous genomewide searches identified regions harboring susceptibility loci on chromosomes 1, 3, 4, 7, 12, and 16. To expand our understanding of the genetic risk profile, we performed a 9-cM genomewide search for susceptibility loci in 268 families containing 353 affected sibling pairs. Previous linkages on chromosomes 12 and 16 were replicated, and the chromosome 4 linkage was extended in this sample. New suggestive evidence for autosomal linkages was observed on chromosomes 1, 6, 10, and 22, with LOD scores of 2.08, 2.07, 2.30, and 1.52, respectively. A maximum LOD score of 1.76 was observed on the X chromosome, for UC, which is consistent with the clinical association of IBD with Ullrich-Turner syndrome. The linkage finding on chromosome 6p is of interest, given the possible contribution of human leukocyte antigen and tumor necrosis-factor genes in IBD. This genomewide linkage scan, done with a large family cohort, has confirmed three previous IBD linkages and has provided evidence for five additional regions that may harbor IBD predisposition genes.

Genetic analysis of inflammatory bowel disease in a large European cohort supports linkage to chromosomes 12 and 16

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) is a complex disorder of unknown etiology. Epidemiological investigations suggest a genetic basis for IBD. Recent genetic studies have identified several IBD linkages. The significance of these linkages will be determined by studies in large patient collections. The aim of this study was to replicate IBD linkages on chromosomes 12 and 16 in a large European cohort.

METHODS

Three hundred fifty-nine affected sibling pairs from 274 kindreds were genotyped using microsatellite markers spanning chromosomes 12 and 16. Affection status of the sibling pairs was defined as Crohn's disease (CD) or ulcerative colitis (UC).

RESULTS

Nonparametric statistical analyses showed linkage for both chromosomes. Two-point results for chromosome 12 peaked at D12S303 (logarithm of odds [LOD], 2.15; P = 0.003) for CD and at D12S75 (LOD, 0.92; P = 0.03) for UC. Multipoint analyses produced a peak LOD of 1.8 for CD. Chromosome 16 showed linkage for CD at marker D16S415 (LOD, 1.52; P = 0.007). Multipoint support peaked above markers D16S409 and D16S411 (LOD, 1.7).

CONCLUSIONS

These data are consistent with linkage of IBD to chromosomes 12 and 16. The replication of genetic risk loci in a large independent family collection indicates important and common susceptibility genes in these regions and will facilitate identification of genes involved in IBD.

Regulation of T-cell differentiation by CD2 and CD28 accessory molecules

It was analysed to what extent the functional T-cell responses that result from T-cell receptor (TcR)/CD3 triggering differ from responses that are induced after simultaneous ligation of CD2 and CD28 accessory molecules. To allow a quantitative comparison of these activation pathways, purified lymphocytes were stimulated with either graded densities of immobilized anti-CD3 monoclonal antibodies (mAb) or with increasing amounts of anti-CD28 mAb in the presence of a constant concentration of anti-CD2 mAb. Both activation systems were sensitive to the regulatory properties of CD11a/CD18 molecules. T-cell stimulation via CD2/CD28 molecules induced a more potent release of interleukin-2 (IL-2) and more pronounced T helper (Th) cell responses than T-cell stimulation via the TcR/CD3 complex, whereas CD25 expression was more readily initiated after T-cell activation via the TcR/CD3 complex. Optimal Th cell differentiation was detected under conditions of suboptimal receptor occupancy whereas, in contrast, optimal cytolytic T lymphocyte (CTL) differentiation required optimal TcR/CD3 or CD2/CD28 engagement. The findings indicate that T-cell differentiation can be influenced in a qualitative manner by the strength of the activation signal provided, and suggest that antigen-specific T-cell responses might be regulated in a quantitative manner through CD2 and CD28 accessory molecules.

Vitamin B12 and bile acid metabolism in patients with partial iieal resection

The vitamin B12 and bile acid metabolism was studied in 20 patients in whom a standardized Bricker procedure without irradiation was performed. No significant vitamin B12 malabsorption, steatorrhea, fecal bile acid loss or bile acid deconjugation was found. Therefore, no long-term adverse metabolic consequences of segmental preterminal ileal resection are to be expected in these patients.