The Effectiveness and Safety of First-Line Thioguanine in Thiopurine-Naïve Inflammatory Bowel Disease Patients

BACKGROUND

Currently thioguanine is solely used as treatment for inflammatory bowel disease after azathioprine and/or mercaptopurine failure. This study aimed to determine the safety, effectiveness, and 12-month drug survival of thioguanine in thiopurine-naïve patients with inflammatory bowel disease.

METHODS

A retrospective cohort study was performed in thiopurine-naïve patients with inflammatory bowel disease treated with thioguanine as first thiopurine derivate. Clinical effectiveness was defined as the continuation of thioguanine without the (re)initiation of concurrent biological therapy, systemic corticosteroids, or a surgical intervention. All adverse events were categorized by the Common Terminology Criteria for Adverse Events.

RESULTS

A total of 114 patients (male 39%, Crohn's disease 53%) were included with a median treatment duration of 25 months and a median thioguanine dosage of 20 mg/d. Clinical effectiveness at 12 months was observed in 53% of patients, and 78% of these responding patients remained responsive until the end of follow-up. During the entire follow-up period, 26 patients were primary nonresponders, 8 had a secondary loss of response, and 11 patients were unable to cease therapy with systemic corticosteroids within 6 months and were therefore classified as nonresponders. After 12 months, thioguanine was still used by 86% of patients. Fifty (44%) patients developed adverse events (grade 1 or 2) and 9 (8%) patients ceased therapy due to the occurrence of adverse events. An infection was documented in 3 patients, none of them requiring hospitalization and pancytopenia occurred in 2 other patients. No signs of nodular regenerative hyperplasia or portal hypertension were observed.

CONCLUSIONS

At 12 months, first-line thioguanine therapy was clinically effective in 53% of thiopurine-naïve inflammatory bowel disease patients with an acceptable safety profile.

Healthy Cotwins Share Gut Microbiome Signatures With Their Inflammatory Bowel Disease Twins and Unrelated Patients

BACKGROUND & AIMS

It is currently unclear whether reported changes in the gut microbiome are cause or consequence of inflammatory bowel disease (IBD). Therefore, we studied the gut microbiome of IBD-discordant and -concordant twin pairs, which offers the unique opportunity to assess individuals at increased risk of developing IBD, namely healthy cotwins from IBD-discordant twin pairs.

METHODS

Fecal samples were obtained from 99 twins (belonging to 51 twin pairs), 495 healthy age-, sex-, and body mass index-matched controls, and 99 unrelated patients with IBD. Whole-genome metagenomic shotgun sequencing was performed. Taxonomic and functional (pathways) composition was compared among healthy cotwins, IBD-twins, unrelated patients with IBD, and healthy controls with multivariable (ie, adjusted for potential confounding) generalized linear models.

RESULTS

No significant differences were observed in the relative abundance of species and pathways between healthy cotwins and their IBD-twins (false discovery rate <0.10). Compared with healthy controls, 13, 19, and 18 species, and 78, 105, and 153 pathways were found to be differentially abundant in healthy cotwins, IBD-twins, and unrelated patients with IBD, respectively (false discovery rate <0.10). Of these, 8 (42.1%) of 19 and 1 (5.6%) of 18 species, and 37 (35.2%) of 105 and 30 (19.6%) of 153 pathways overlapped between healthy cotwins and IBD-twins, and healthy cotwins and unrelated patients with IBD, respectively. Many of the shared species and pathways have previously been associated with IBD. The shared pathways include potentially inflammation-related pathways, for example, an increase in propionate degradation and L-arginine degradation pathways.

CONCLUSIONS

The gut microbiome of healthy cotwins from IBD-discordant twin pairs displays IBD-like signatures. These IBD-like microbiome signatures might precede the onset of IBD. However, longitudinal follow-up studies are needed to infer a causal relationship.

Associations of Pathogenic Variants in MLH1, MSH2, and MSH6 With Risk of Colorectal Adenomas and Tumors and With Somatic Mutations in Patients With Lynch Syndrome

BACKGROUND & AIMS

Lynch syndrome is caused by variants in DNA mismatch repair (MMR) genes and associated with an increased risk of colorectal cancer (CRC). In patients with Lynch syndrome, CRCs can develop via different pathways. We studied associations between Lynch syndrome-associated variants in MMR genes and risks of adenoma and CRC and somatic mutations in APC and CTNNB1 in tumors in an international cohort of patients.

METHODS

We combined clinical and molecular data from 3 studies. We obtained clinical data from 2747 patients with Lynch syndrome associated with variants in MLH1, MSH2, or MSH6 from Germany, the Netherlands, and Finland who received at least 2 surveillance colonoscopies and were followed for a median time of 7.8 years for development of adenomas or CRC. We performed DNA sequence analyses of 48 colorectal tumors (from 16 patients with mutations in MLH1, 29 patients with mutations in MSH2, and 3 with mutations in MSH6) for somatic mutations in APC and CTNNB1.

RESULTS

Risk of advanced adenoma in 10 years was 17.8% in patients with pathogenic variants in MSH2 vs 7.7% in MLH1 (P < .001). Higher proportions of patients with pathogenic variants in MLH1 or MSH2 developed CRC in 10 years (11.3% and 11.4%) than patients with pathogenic variants in MSH6 (4.7%) (P = .001 and P = .003 for MLH1 and MSH2 vs MSH6, respectively). Somatic mutations in APC were found in 75% of tumors from patients with pathogenic variants in MSH2 vs 11% in MLH1 (P = .015). Somatic mutations in CTNNB1 were found in 50% of tumors from patients with pathogenic variants in MLH1 vs 7% in MSH2 (P = .002). None of the 3 tumors with pathogenic variants in MSH6 had a mutation in CTNNB1, but all had mutations in APC.

CONCLUSIONS

In an analysis of clinical and DNA sequence data from patients with Lynch syndrome from 3 countries, we associated pathogenic variants in MMR genes with risk of adenoma and CRC, and somatic mutations in APC and CTNNB1 in colorectal tumors. If these findings are confirmed, surveillance guidelines might be adjusted based on MMR gene variants.

No Difference in Colorectal Cancer Incidence or Stage at Detection by Colonoscopy Among 3 Countries With Different Lynch Syndrome Surveillance Policies

BACKGROUND & AIMS

Patients with Lynch syndrome are at high risk for developing colorectal cancer (CRC). Regular colonoscopic surveillance is recommended, but there is no international consensus on the appropriate interval. We investigated whether shorter intervals are associated with lower CRC incidence and detection at earlier stages by comparing the surveillance policies in Germany, which evaluates patients by colonoscopy annually, in the Netherlands (patients evaluated at 1-2-year intervals), and Finland (patients evaluated at 2-3-year intervals).

METHODS

We collected data from 16,327 colonoscopic examinations (conducted from 1984 through 2015) of 2747 patients with Lynch syndrome (pathogenic variants in the MLH1, MSH2, or MSH6 genes) from the German HNPCC Consortium, the Dutch Lynch Syndrome Registry, and the Finnish Lynch Syndrome Registry. Our analysis included 23,309 person-years of cumulative observation time. Time from the index colonoscopy to incident CRC or adenoma was analyzed using the Kaplan-Meier method; groups were compared using the log-rank test. We performed multivariable Cox regression analyses to identify factors associated with CRC risk (diagnosis of CRC before the index colonoscopy, sex, mutation, age, and presence of adenoma at the index colonoscopy).

RESULTS

The 10-year cumulative CRC incidence ranged from 4.1% to 18.4% in patients with low- and high-risk profiles, respectively, and varied with age, sex, mutation, and prior detection of CRC or adenoma. Observed colonoscopy intervals were largely in accordance with the country-specific recommendations. We found no significant differences in cumulative CRC incidence or CRC stage at detection among countries. There was no significant association between CRC stage and time since last colonoscopy.

CONCLUSIONS

We did not find a significant reduction in CRC incidence or stage of detection in Germany (annual colonoscopic surveillance) than in countries with longer surveillance intervals (the Netherlands, with 1-2-year intervals, and Finland, with 2-3-year intervals). Overall, we did not find a significant association of the interval with CRC risk, although age, sex, mutation, and prior neoplasia were used to individually modify colonoscopy intervals. Studies are needed to develop and validate risk-adapted surveillance strategies and to identify patients who benefit from shorter surveillance intervals.

The Polyp Manager: a new tool for optimal polyp documentation during colonoscopy. A pilot study

BACKGROUND AND STUDY AIMS

Conventional reporting of polyps is often incomplete. We tested the Polyp Manager (PM), a new software application permitting the endoscopist to document polyps in real time during colonoscopy. We studied completeness of polyp descriptions, user-friendliness and the potential time benefit.

PATIENTS AND METHODS

In two Dutch hospitals colonoscopies were performed with PM (as a touchscreen endoscopist-operated device or nurse-operated desktop application). Completeness of polyp descriptions was compared to a historical group with conventional reporting (CRH). Prospectively, we compared user-friendliness (VAS-scores) and time benefit of the endoscopist-operated PM to conventional reporting (CR) in one hospital. Duration of colonoscopy and time needed to report polyps and provide a pathology request were measured. Provided that using PM does not prolong colonoscopy, the sum of the latter two was considered as a potential time-benefit if the PM were fully integrated into a digital reporting system.

RESULTS

A total of 144 regular colonoscopies were included in the study. Both groups were comparable with regard to patient characteristics, duration of colonoscopy and number of polyps. Using the PM did reduce incomplete documentation of the following items in CRH-reports: location (96 % vs 82 %, P = 0.01), size (95 % vs 89 %, P = 0.03), aspect (71 % vs 36 %, P < 0.001) and completeness of removal (61 % vs 37 %, P < 0.001). In the prospective study 23 PM-colonoscopies where compared to 28 CR-colonoscopies. VAS-scores were significantly higher in the endoscopist-operated PM group. Time to report was 01:27 ± 01:43 minutes (median + interquartile range) in the entire group (PM as CR), reflecting potential time benefit per colonoscopy.

CONCLUSIONS

The PM is a user-friendly tool that seems to improve completeness of polyp reporting. Once integrated with digital reporting systems, it is probably time saving as well.

Evolution of Costs of Inflammatory Bowel Disease over Two Years of Follow-Up

Background

With the increasing use of anti-TNF therapy in inflammatory bowel disease (IBD), a shift of costs has been observed with medication costs replacing hospitalization and surgery as major cost driver. We aimed to explore the evolution of IBD-related costs over two years of follow-up.

Methods and Findings

In total 1,307 Crohn's disease (CD) patients and 915 ulcerative colitis (UC) patients were prospectively followed for two years by three-monthly web-based questionnaires. Changes of healthcare costs, productivity costs and out-of-pocket costs over time were assessed using mixed model analysis. Multivariable logistic regression analysis was used to identify costs drivers. In total 737 CD patients and 566 UC were included. Total costs were stable over two years of follow-up, with annual total costs of €7,835 in CD and €3,600 in UC. However, within healthcare costs, the proportion of anti-TNF therapy-related costs increased from 64% to 72% in CD (p<0.01) and from 31% to 39% in UC (p < 0.01). In contrast, the proportion of hospitalization costs decreased from 19% to 13% in CD (p<0.01), and 22% to 15% in UC (p < 0.01). Penetrating disease course predicted an increase of healthcare costs (adjusted odds ratio (adj. OR) 1.95 (95% CI 1.02–3.37) in CD and age <40 years in UC (adj. OR 4.72 (95% CI 1.61–13.86)).

Conclusions

BD-related costs remained stable over two years. However, the proportion of anti-TNF-related healthcare costs increased, while hospitalization costs decreased. Factors associated with increased costs were penetrating disease course in CD and age <40 in UC.

Equivalent Helicobacter pylori infection rates in Lynch syndrome mutation carriers with and without a first-degree relative with gastric cancer

BACKGROUND

Patients with Lynch syndrome (LS) are at an increased risk of developing gastric cancer. In 2010, a guideline that recommended to screen all patients for Helicobacter pylori was implemented in the Netherlands. H. pylori is an important risk factor in the development of gastric cancer in the general population, and eradication of the bacterium reduces this risk. We aimed to assess the proportion of LS patients being tested and the yield and also addressed the question whether H. pylori infection is more prevalent in LS families with known cases of gastric cancer.

METHODS

Proven mutation carriers from five different Dutch hospitals were included. The implementation of H. pylori screening and its outcome was examined. The observation period was 2008-2013. The presence of first-degree family members with gastric cancer was noted, and it was observed if H. pylori infection was more prevalent in Lynch families with known cases of gastric cancer. Obtainable endoscopy reports were reviewed.

RESULTS

Four hundred forty-three (male, 184) proven mutation carriers were included. The proportion of patients screened increased after 2010, from 37 to 68%. Twenty percent of the patients were infected. The 25 patients who had a first-degree family member with gastric cancer did not have a higher infection rate. In 30% of cases, an endoscopy was performed; in four patients, intestinal metaplasia and in eight patients, gastric cancer was found.

CONCLUSION

The recommendation to screen for H. pylori is increasingly followed. The prevalence of infection in this patient group does not differ from the general population. Patients who had a first-degree family member with gastric cancer did not have a higher infection rate.

Comparison of Costs and Quality of Life in Ulcerative Colitis Patients with an Ileal Pouch-Anal Anastomosis, Ileostomy and Anti-TNFα Therapy

BACKGROUND AND AIMS

More data are warranted on the economic impact of different treatment strategies in ulcerative colitis (UC) patients. We compared the costs and quality of life of UC patients with a pouch reconstruction, an ileostomy or anti-tumour necrosis factor α (TNFα) therapy.

METHODS

UC patients filled out 3-monthly questionnaires for 2 years. Differences in 3-monthly healthcare costs, productivity costs and patient costs were tested using mixed model analysis. Quality of life was assessed employing the ) and the inflammatory bowel disease questionnaire (IBDQ).

RESULTS

Out of 915 UC patients, 81 (9%) had a pouch and 48 (5%) an ileostomy, and 34 (4%) were on anti-TNFα therapy. Anti-TNFα-treated patients reported high UC related-healthcare costs per 3 months (€5350). Medication use accounted for 92% of healthcare costs. UC-attributable healthcare costs were 3-fold higher in ileostomy patients compared with pouch patients (€1581 versus €407; p < 0.01). Main cost drivers in ileostomy patients were healthcare costs and ileostomy supplies (2 and 23% of healthcare costs, respectively). In pouch patients, the main cost driver was hospitalization, accounting for 50% of healthcare costs. Productivity loss did not differ between pouch and ileostomy patients (€483 versus €377; p < 0.23), but was significantly higher in anti-TNFα-treated patients (€1085). No difference was found in IBDQ scores, but pouch patients were found to have higher quality-adjusted life years than ileostomy patients and anti-TNFα-treated patients (0.90 [interquartile range 0.78-1.00] versus 0.84 [0.78-1.00] and 0.84 [0.69-1.00], respectively; p < 0.01).

CONCLUSION

Patients receiving anti-TNFα therapy reported the highest healthcare cost, in which medication use was the major cost driver. Ileostomy patients were three times more expensive than pouch patients due to frequent hospitalization and ileostomy supplies.

Association between postprandial symptoms and gastric emptying after sleeve gastrectomy

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric procedure. However, postprandial symptoms can compromise its beneficial effect. It is not known if a changed gastric emptying and these symptoms are related. This study aimed to assess the association between postprandial symptoms and the gastric emptying pattern after LSG.

METHODS

A gastric emptying study with a solid and liquid meal component was performed in the second year after LSG. Before the test, symptoms were assessed using a standardized questionnaire, and during the test, symptoms were scored on a visual analog scale (VAS). Gastric emptying results were expressed as lag phase, half time of gastric emptying (T½), and caloric emptying rate/minute.

RESULTS

Twenty patients (14 F/6 M; age 45.6 ± 7.7 years, weight 93.4 ± 28.2 kg, BMI 31.6 ± 8.1 kg/m(2)) participated in this study; 13 had a low symptom score (≤9, group I), 7 a high symptom score (≥18, group II). VAS scores for epigastric pain, nausea, and belching were significantly higher in group II. Lag phase (solid) was 6.4 ± 4.5 min in group I, 7.3 ± 6.3 in group II (p = 0.94); T½ (solid) was 40.6 ± 10.0 min in group I, 34.4 ± 9.3 in group II (p = 0.27); caloric emptying rate was 3.9 ± 0.6 kcal/min in group I, 3.9 ± 1.0 kcal/min in group II (p = 0.32).

CONCLUSIONS

Patients with postprandial symptoms after LSG reported more symptoms during the gastric emptying study than patients without symptoms. However, there was no difference between gastric emptying characteristics between both groups, suggesting that abnormal gastric emptying is not a major determinant of postprandial symptoms after LSG.

Effect of sleeve gastrectomy on gastroesophageal reflux

Laparoscopic sleeve gastrectomy (LSG) is effective as a stand-alone bariatric procedure. Despite its positive effect with regard to weight loss and improvement of obesity-related co-morbidities, some patients develop gastroesophageal reflux symptoms postoperatively. The pathogenesis of these symptoms is not completely understood. Hence, this study aimed to assess the effect of sleeve gastrectomy on acid and non-acid gastroesophageal reflux, reflux symptoms and esophageal function. In a prospective study, patients underwent esophageal function tests (high-resolution manometry (HRM) and 24-h pH/impedance metry) before and 3 months after LSG. Preoperative and postoperative symptoms were assessed using the Reflux Disease Questionnaire (RDQ). In total, 20 patients (4 male/16 female, mean age 43 ± 12 years, mean weight 137.3 ± 25 kg, and mean BMI 47.6 ± 6.1 kg/m(2)) participated in this study. GERD symptoms did not significantly change after sleeve gastrectomy, but other upper gastrointestinal symptoms, particularly belching, epigastric pain and vomiting increased. Esophageal acid exposure significantly increased after sleeve gastrectomy: upright from 5.1 ± 4.4 to 12.6 ± 9.8% (p = 0.003), supine from 1.4 ± 2.4 to 11 ± 15% (p = 0.003) and total acid exposure from 4.1 ± 3.5 to 12 ± 10.4% (p = 0.004). The percentage of normal peristaltic contractions remained unchanged, but the distal contractile integral decreased after LSG from 2,006.0 ± 1,806.3 to 1,537.4 ± 1,671.8 mmHg · cm · s (p = 0.01). The lower esophageal sphincter (LES) pressure decreased from 18.3 ± 9.2 to 11.0 ± 7.0 mmHg (p = 0.02). After LSG, patients have significantly higher esophageal acid exposure, which may well be due to a decrease in LES resting pressure following the procedure.

Risk factors of work disability in patients with inflammatory bowel disease--a Dutch nationwide web-based survey: work disability in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is associated with high costs to society. Few data on the impact of IBD on work disability and potential predictive factors are available.

AIM

To assess the prevalence of and predictive factors for work disability in Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

A web-based questionnaire was sent out in seven university hospitals and seven general hospitals in the Netherlands. Initially, 3050 adult IBD patients were included in this prospective, nationwide cohort study, whereof 2629 patients were within the working-age (18-64 years). We used the baseline questionnaire to assess the prevalence rates of work disability in CD and UC patients within working-age. Prevalence rates were compared with the Dutch background population using age- and sex-matched data obtained from Statistics Netherlands. Multivariable logistic regression analyses were performed to identify independent demographic- and disease-specific risk factors for work disability.

RESULTS

In CD, 18.3% of patients was fully disabled and 8.8% partially disabled, compared to 9.5% and 5.4% in UC patients (p<0.01), respectively. Compared to Dutch controls, the prevalence was significantly higher, especially in CD patients. Higher age, low education, depression, chronic back pain, joint manifestations and typical disease-related risk factors such as penetrating disease course and surgery in the past were all found to be associated with work disability.

CONCLUSION

We report high work disability rates in a large sample of IBD patients in the Netherlands. CD patients suffer more frequently from work disability than UC patients. A combination of demographic and disease-related factors is predictive of work disability.

Healthcare costs of inflammatory bowel disease have shifted from hospitalisation and surgery towards anti-TNFα therapy: results from the COIN study

OBJECTIVE

The introduction of anti tumour necrosis factor-α (anti-TNFα) therapy might impact healthcare expenditures, but there are limited data regarding the costs of inflammatory bowel diseases (IBD) following the introduction of these drugs. We aimed to assess the healthcare costs and productivity losses in a large cohort of IBD patients.

DESIGN

Crohn's disease (CD) and ulcerative colitis (UC) patients from seven university hospitals and seven general hospitals were invited to fill-out a web-based questionnaire. Cost items were derived from a 3 month follow-up questionnaire and categorised in outpatient clinic, diagnostics, medication, surgery and hospitalisation. Productivity losses included sick leave of paid and unpaid work. Costs were expressed as mean 3-month costs per patients with a 95% CI obtained using non-parametric bootstrapping.

RESULTS

A total of 1315 CD patients and 937 UC patients were included. Healthcare costs were almost three times higher in CD as compared with UC, €1625 (95% CI €1476 to €1775) versus €595 (95% CI €505 to €685), respectively (p<0.01). Anti-TNFα use was the main costs driver, accounting for 64% and 31% of the total cost in CD and UC. Hospitalisation and surgery together accounted for 19% and <1% of the healthcare costs in CD and 23% and 1% in UC, respectively. Productivity losses accounted for 16% and 39% of the total costs in CD and UC.

CONCLUSIONS

We showed that healthcare costs are mainly driven by medication costs, most importantly by anti-TNFα therapy. Hospitalisation and surgery accounted only for a minor part of the healthcare costs.

One to 2-year surveillance intervals reduce risk of colorectal cancer in families with Lynch syndrome

BACKGROUND & AIMS

Two percent to 4% of all cases of colorectal cancer (CRC) are associated with Lynch syndrome. Dominant clustering of CRC (non-Lynch syndrome) accounts for 1%-3% of the cases. Because carcinogenesis is accelerated in Lynch syndrome, an intensive colonoscopic surveillance program has been recommended since 1995. The aim of the study was to evaluate the effectiveness of this program.

METHODS

The study included 205 Lynch syndrome families with identified mutations in one of the mismatch repair genes (745 mutation carriers). We also analyzed data from non-Lynch syndrome families (46 families, 344 relatives). Patients were observed from January 1, 1995, until January 1, 2009. End points of the study were CRC or date of the last colonoscopy.

RESULTS

After a mean follow-up of 7.2 years, 33 patients developed CRC under surveillance. The cumulative risk of CRC was 6% after the 10-year follow-up period. The risk of CRC was higher in carriers older than 40 years and in carriers of MLH1 and MSH2 mutations. After a mean follow-up of 7.0 years, 6 cases of CRC were detected among non-Lynch syndrome families. The risk of CRC was significantly higher among families with Lynch syndrome, compared with those without.

CONCLUSIONS

With surveillance intervals of 1-2 years, members of families with Lynch syndrome have a lower risk of developing CRC than with surveillance intervals of 2-3 years. Because of the low risk of CRC in non-Lynch syndrome families, a less intensive surveillance protocol can be recommended.

Increased consumption of fatty and lean fish reduces serum C-reactive protein concentrations but not inflammation markers in feces and in colonic biopsies

Fish consumption is associated with a reduced colorectal cancer risk. A possible mechanism by which fish consumption could decrease colorectal cancer risk is by reducing inflammation. However, thus far, intervention studies investigating both systemic and local gut inflammation markers are lacking. Our objective in this study was to investigate the effects of fatty and lean fish consumption on inflammation markers in serum, feces, and gut. In an intervention study, participants were randomly allocated to receive dietary advice (DA) plus either 300 g of fatty fish (salmon) or 300 g of lean fish (cod) per week for 6 mo, or only DA. Serum C-reactive protein (CRP) concentrations were measured pre- and postintervention (n = 161). In a subgroup (n = 52), we explored the effects of the fish intervention on fecal calprotectin and a wide range of cytokines and chemokines in fecal water and in colonic biopsies. Serum CRP concentrations were lower in the salmon (-0.5 mg/L; 95% CI -0.9, -0.2) and cod (-0.4 mg/L; 95% CI -0.7, 0.0) groups compared with the DA group. None of the inflammation markers in fecal water and colonic biopsies differed between the DA group and the groups that consumed extra fish. In conclusion, increasing salmon or cod consumption for 6 mo resulted in lower concentrations of the systemic inflammation marker CRP. However, exploratory analysis of local markers of inflammation in the colon or feces did not reveal an effect of fish consumption.

Fish consumption and markers of colorectal cancer risk: a multicenter randomized controlled trial

BACKGROUND

Diet is a major factor in the etiology of colorectal cancer, with high fish consumption possibly decreasing colorectal cancer risk, as was shown in several observational studies. To date, no intervention trials have examined the possible beneficial effects of fish intake on colorectal cancer risk.

OBJECTIVE

The objective was to investigate the effects of a 6-mo intervention with oil-rich or lean fish on apoptosis and mitosis within the colonic crypt.

DESIGN

In a multicenter, randomized, controlled intervention trial, patients with colorectal polyps, inactive ulcerative colitis, or no macroscopic signs of disease were recruited (n = 242) and randomly allocated to receive dietary advice plus either 300 g oil-rich fish (salmon) per week (n = 82), 300 g lean fish (cod) per week (n = 78), or only dietary advice (DA) (n = 82). Apoptosis and mitosis were measured in colonic biopsy samples collected before and after intervention (n = 213).

RESULTS

The total number of apoptotic cells per crypt did not increase in the salmon or cod group: -0.10 (95% CI: -0.36, 0.16) and -0.06 (95% CI: -0.32, 0.20), respectively, compared with the DA group. The total number of mitotic cells per crypt decreased nonsignificantly in the salmon group (-0.87; 95% CI: -2.41, 0.68) and in the cod group (-1.04; 95% CI: -2.62, 0.53) compared with the DA group. Furthermore, the distribution of mitosis within the crypt did not significantly change in either group.

CONCLUSION

An increase in the consumption of either oil-rich or lean fish to 2 portions weekly over 6 mo does not markedly change apoptotic and mitotic rates in the colonic mucosa. This trial was registered at www.clinicaltrials.gov as NCT00145015.