Exploring the gut DNA virome in fecal immunochemical test stool samples reveals associations with lifestyle in a large population-based study

Stool samples for fecal immunochemical tests (FIT) are collected in large numbers worldwide as part of colorectal cancer screening programs. Employing FIT samples from 1034 CRCbiome participants, recruited from a Norwegian colorectal cancer screening study, we identify, annotate and characterize more than 18000 DNA viruses, using shotgun metagenome sequencing. Only six percent of them are assigned to a known taxonomic family, with Microviridae being the most prevalent viral family. Linking individual profiles to comprehensive lifestyle and demographic data shows 17/25 of the variables to be associated with the gut virome. Physical activity, smoking, and dietary fiber consumption exhibit strong and consistent associations with both diversity and relative abundance of individual viruses, as well as with enrichment for auxiliary metabolic genes. We demonstrate the suitability of FIT samples for virome analysis, opening an opportunity for large-scale studies of this enigmatic part of the gut microbiome. The diverse viral populations and their connections to the individual lifestyle uncovered herein paves the way for further exploration of the role of the gut virome in health and disease.

Lifestyle changes in middle age and risk of cancer: evidence from the European Prospective Investigation into Cancer and Nutrition

In this study, we aimed to provide novel evidence on the impact of changing lifestyle habits on cancer risk. In the EPIC cohort, 295,865 middle-aged participants returned a lifestyle questionnaire at baseline and during follow-up. At both timepoints, we calculated a healthy lifestyle index (HLI) score based on cigarette smoking, alcohol consumption, body mass index and physical activity. HLI ranged from 0 (most unfavourable) to 16 (most favourable). We estimated the association between HLI change and risk of lifestyle-related cancers-including cancer of the breast, lung, colorectum, stomach, liver, cervix, oesophagus, bladder, and others-using Cox regression models. We reported hazard ratios (HR) with 95% confidence intervals (CI). Median time between the two questionnaires was 5.7 years, median age at follow-up questionnaire was 59 years. After the follow-up questionnaire, we observed 14,933 lifestyle-related cancers over a median follow-up of 7.8 years. Each unit increase in the HLI score was associated with 4% lower risk of lifestyle-related cancers (HR 0.96; 95%CI 0.95-0.97). Among participants in the top HLI third at baseline (HLI > 11), those in the bottom third at follow-up (HLI ≤ 9) had 21% higher risk of lifestyle-related cancers (HR 1.21; 95%CI 1.07-1.37) than those remaining in the top third. Among participants in the bottom HLI third at baseline, those in the top third at follow-up had 25% lower risk of lifestyle-related cancers (HR 0.75; 95%CI 0.65-0.86) than those remaining in the bottom third. These results indicate that lifestyle changes in middle age may have a significant impact on cancer risk.

Lower participation among immigrants in colorectal cancer screening in Norway

Introduction

Organized cancer screening programs should be equally accessible for all groups in society. We assessed differences in participation in colorectal cancer (CRC) screening among different immigrant groups.

Methods

Between 2012 and 2019, 140,000 individuals aged 50 to 74 years were randomly invited to sigmoidoscopy or repeated faecal immunochemical test (FIT) in a CRC screening trial. In this study, we included 46,919 individuals invited to sigmoidoscopy and 70,018 invited to the first round of FIT between 2012 and 2017. We examined difference in participation between non-immigrants and immigrants, and within different immigrant groups by geographic area of origin, using logistic regression models, adjusted for several sociodemographic factors and health factors.

Results

In total, we included 106,695 non-immigrants and 10,242 immigrants. The participation rate for FIT was 60% among non-immigrants, 58% among immigrants from Western countries and 37% among immigrants from non-Western countries. The participation rate for sigmoidoscopy was 53% among non-immigrants, 48% among immigrants from Western countries and 23% among immigrants from non-Western countries. Compared to non-immigrants, multivariate adjusted odds ratio for non-participation in FIT screening was 1.13 (95% confidence interval 1.04-1.23) and 1.82 (1.69-1.96) for immigrants from Western and non-Western countries. The corresponding numbers in sigmoidoscopy screening were 1.34 (1.21-1.48) and 2.83 (2.55-3.14). The lowest participation was observed in immigrants from Eastern Europe, Northern Africa and Western Asia, and South-Central Asia.

Conclusion

Participation in CRC screening in Norway was particularly low among non-Western immigrants, which could put them at increased risk for late stage diagnosis of CRC. Participation was lower in sigmoidoscopy screening than in FIT screening, especially among immigrants from non-Western countries.

Effect of invitation letter in language of origin on screening attendance: randomised controlled trial in BreastScreen Norway

OBJECTIVE

To explore attendance at organised mammographic screening among immigrant groups that received an invitation letter and information leaflet (invitation) in their language of origin and Norwegian compared with Norwegian only.

DESIGN

Randomised controlled trial.

SETTING

Population based screening programme for breast cancer in Norway (BreastScreen Norway), which invites women aged 50-69 to two-view mammographic screening biennially.

PARTICIPANTS

All women invited to BreastScreen Norway in the study period April 2021 to June 2022 whose language of origin was Arabic (women born in Algeria, Egypt, Lebanon, Iraq, Palestine, Sudan, Syria, Tunisia, or Morocco), English (women born in the Philippines), Polish (women born in Poland), Somali (women born in Somalia), or Urdu (women born in Pakistan) (n=11 347).

INTERVENTION

The study group received an invitation to screening in their language of origin and in Norwegian, whereas the control group received an invitation in Norwegian only during the study period.

MAIN OUTCOME MEASURE

Attendance at BreastScreen Norway during the study period.

RESULTS

Overall attendance was 46.5% (2642/5683) in the study group and 47.4% (2682/5664) in the control group. No statistical differences in attendance were observed after stratification by language of invitation, age at invitation, or years since immigration.

CONCLUSIONS

No difference in attendance was observed between immigrant women invited to BreastScreen Norway in their language of origin and in Norwegian compared with Norwegian only. Several barriers to cancer screening may exist among immigrants, and translating the invitation is probably only a part of a complex explanation.

TRIAL REGISTRATION

NCT04672265.

CLINICALTRIALS

gov NCT04672265.

Development and validation of a risk prediction model for post-polypectomy colorectal cancer in the USA: a prospective cohort study

Background

Effective risk stratification tools for post-polypectomy colorectal cancer (PPCRC) are lacking. We aimed to develop an effective risk stratification tool for the prediction of PPCRC in three large population-based cohorts and to validate the tool in a clinical cohort.

Methods

Leveraging the integrated endoscopic, histopathologic and epidemiologic data in three U.S population-based cohorts of health professional (the Nurses' Health Study (NHS) I, II and Health Professionals Follow-up Study (HPFS)), we developed a risk score to predict incident PPCRC among 26,741 patients with a polypectomy between 1986 and 2017. We validated the PPCRC score in the Mass General Brigham (MGB) Colonoscopy Cohort (Boston, Massachusetts, U.S) of 76,603 patients with a polypectomy between 2007 and 2018. In all four cohorts, we collected detailed data on patients' demographics, endoscopic history, polyp features, and lifestyle factors at polypectomy. The outcome, incidence of PPCRC, was assessed by biennial follow-up questionnaires in the NHS/HPFS cohorts, and through linkage to the Massachusetts Cancer Registry in the MGB cohort. In all four cohorts, individuals who were diagnosed with CRC or died before baseline or within six months after baseline were excluded. We used Cox regression to calculate the hazard ratio (HR), 95% confidence interval (CI) and assessed the discrimination using C-statistics and reclassification using the Net Reclassification Improvement (NRI).

Findings

During a median follow-up of 12.8 years (interquartile range (IQR): 9.3, 16.7) and 5.1 years (IQR: 2.7, 7.8) in the NHS/HPFS and MGB cohorts, we documented 220 and 241 PPCRC cases, respectively. We identified a PPCRC risk score based on 11 predictors. In the validation cohort, the PPCRC risk score showed a strong association with PPCRC risk (HR for high vs. low, 3.55, 95% CI, 2.59-4.88) and demonstrated a C-statistic (95% CI) of 0.75 (0.70-0.79), and was discriminatory even within the low- and high-risk polyp groups (C-statistic, 0.73 and 0.71, respectively) defined by the current colonoscopy surveillance recommendations, leading to a NRI of 45% (95% CI, 36-54%) for patients with PPCRC.

Interpretation

We developed and validated a risk stratification model for PPCRC that may be useful to guide tailored colonoscopy surveillance. Further work is needed to determine the optimal surveillance interval and test the added value of other predictors of PPCRC beyond those included in the current study, along with implementation studies.

Funding

US National Institutes of Health, the American Cancer Society, the South-Eastern Norway Regional Health Authority, the Deutsche Forschungsgemeinschaft.

Associations of the 2018 World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) cancer prevention recommendations with stages of colorectal carcinogenesis

BACKGROUND

While adherence to cancer prevention recommendations is linked to lower risk of colorectal cancer (CRC), few have studied associations across the entire spectrum of colorectal carcinogenesis. Here, we studied the relationship of the standardized 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Score for cancer prevention recommendations with detection of colorectal lesions in a screening setting. As a secondary objective, we examined to what extent the recommendations were being followed in an external cohort of CRC patients.

METHODS

Adherence to the seven-point 2018 WCRF/AICR Score was measured in screening participants receiving a positive fecal immunochemical test and in CRC patients participating in an intervention study. Dietary intake, body fatness and physical activity were assessed using self-administered questionnaires. Multinomial logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for screen-detected lesions.

RESULTS

Of 1486 screening participants, 548 were free from adenomas, 524 had non-advanced adenomas, 349 had advanced lesions and 65 had CRC. Adherence to the 2018 WCRF/AICR Score was inversely associated with advanced lesions; OR 0.82 (95% CI 0.71, 0.94) per score point, but not with CRC. Of the seven individual components included in the score, alcohol, and BMI seemed to be the most influential. Of the 430 CRC patients included in the external cohort, the greatest potential for lifestyle improvement was seen for the recommendations concerning alcohol and red and processed meat, where 10% and 2% fully adhered, respectively.

CONCLUSIONS

Adherence to the 2018 WCRF/AICR Score was associated with lower probability of screen-detected advanced precancerous lesions, but not CRC. Although some components of the score seemed to be more influential than others (i.e., alcohol and BMI), taking a holistic approach to cancer prevention is likely the best way to prevent the occurrence of precancerous colorectal lesions.

Changes in Lifestyle and Risk of Colorectal Cancer in the European Prospective Investigation Into Cancer and Nutrition

INTRODUCTION

We investigated the impact of changes in lifestyle habits on colorectal cancer (CRC) risk in a multicountry European cohort.

METHODS

We used baseline and follow-up questionnaire data from the European Prospective Investigation into Cancer cohort to assess changes in lifestyle habits and their associations with CRC development. We calculated a healthy lifestyle index (HLI) score based on smoking status, alcohol consumption, body mass index, and physical activity collected at the 2 time points. HLI ranged from 0 (most unfavorable) to 16 (most favorable). We estimated the association between HLI changes and CRC risk using Cox regression models and reported hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

Among 295,865 participants, 2,799 CRC cases were observed over a median of 7.8 years. The median time between questionnaires was 5.7 years. Each unit increase in HLI from the baseline to the follow-up assessment was associated with a statistically significant 3% lower CRC risk. Among participants in the top tertile at baseline (HLI > 11), those in the bottom tertile at follow-up (HLI ≤ 9) had a higher CRC risk (HR 1.34; 95% CI 1.02-1.75) than those remaining in the top tertile. Among individuals in the bottom tertile at baseline, those in the top tertile at follow-up had a lower risk (HR 0.77; 95% CI 0.59-1.00) than those remaining in the bottom tertile.

DISCUSSION

Improving adherence to a healthy lifestyle was inversely associated with CRC risk, while worsening adherence was positively associated with CRC risk. These results justify and support recommendations for healthy lifestyle changes and healthy lifestyle maintenance for CRC prevention.

Use of surveillance colonoscopy among individuals with removal of high-risk polyps according to the US Multi-Society Task Force recommendations

BACKGROUND

Individuals with colorectal polypectomy are recommended to undergo surveillance colonoscopies at certain intervals to prevent subsequent colorectal cancer. Use of postpolypectomy surveillance according to the 2006 US Multi-Society Task Force (USMSTF) recommendations in an integrated health care system was investigated.

METHODS

Use of surveillance colonoscopies was prospectively assessed among 3691 patients with removal of high-risk polyps at a screening colonoscopy during 2007-2012 in the Mass General Brigham Colonoscopy Cohort. With the follow-up up to 2017, the compliance with, overuse, and underuse of postpolypectomy surveillance according to the 2006 USMSTF recommendations was assessed. Surveillance use according to demographic factors was also investigated.

RESULTS

During a median follow-up of 4.4 years (5th percentile, 95th percentile, 1.0, 9.9) 2360 (64%) patients had undergone a surveillance colonoscopy, among whom 758 (21%) were considered compliant with the USMSTF recommendations. A substantial underuse of surveillance colonoscopies of 62% was observed. Older age and lower income were associated with a higher incidence of underuse, whereas having a family history of colorectal cancer were associated with lower incidence of underuse. Overuse of surveillance colonoscopies was present in 17% of patients but showed no significant associations with demographic factors.

CONCLUSION

Substantial underuse of surveillance in patients with high-risk polyps was observed, particularly those with low income and older age. Efforts are needed to improve delivery and use of surveillance colonoscopy.

PLAIN LANGUAGE SUMMARY

The US Multi-Society Task Force recommends follow-up surveillance colonoscopy after polyp removal in the bowel, with intervals depending on the most severe findings. Adherence to surveillance recommendations in a large study with up to 10 years of follow-up among patients with high-risk polyps was investigated. Only 21% of patients adhered to the surveillance recommendations, whereas 62% showed delayed or no use of surveillance. Findings highlight the need for improved use of surveillance colonoscopy among patients at high risk of colorectal cancer.

Long-term follow-up of colorectal cancer screening attendees identifies differences in Phascolarctobacterium spp. using 16S rRNA and metagenome sequencing

Background

The microbiome has been implicated in the initiation and progression of colorectal cancer (CRC) in cross-sectional studies. However, there is a lack of studies using prospectively collected samples.

Methods

From the Norwegian Colorectal Cancer Prevention (NORCCAP) trial, we analyzed 144 archived fecal samples from participants who were diagnosed with CRC or high-risk adenoma (HRA) at screening and from participants who remained cancer-free during 17 years of follow-up. We performed 16S rRNA sequencing of all the samples and metagenome sequencing on a subset of 47 samples. Differences in taxonomy and gene content between outcome groups were assessed for alpha and beta diversity and differential abundance.

Results

Diversity and composition analyses showed no significant differences between CRC, HRA, and healthy controls. Phascolarctobacterium succinatutens was more abundant in CRC compared with healthy controls in both the 16S and metagenome data. The abundance of Bifidobacterium and Lachnospiraceae spp. was associated with time to CRC diagnosis.

Conclusion

Using a longitudinal study design, we identified three taxa as being potentially associated with CRC. These should be the focus of further studies of microbial changes occurring prior to CRC diagnosis.

Type and Severity of Mental Illness and Participation in Colorectal Cancer Screening

INTRODUCTION

The effectiveness of colorectal cancer screening programs depends on the participation rate. This study examined the association between type and severity of mental illness and colorectal cancer screening participation.

METHODS

Between 2012 and 2017, a total of 46,919 individuals were invited to sigmoidoscopy screening in Norway, and 70,019 were invited to fecal immunochemical testing. In 2022, logistic regression was used to evaluate the association between the use of antipsychotics, anxiolytics, hypnotics, and antidepressants in the year preceding the screening invitation and screening participation, adjusted for demographic and socioeconomic factors. Defined daily doses of individual drugs were used to assess dose‒response relationships.

RESULTS

Overall, 19.2% (24.8% of women, 13.4% of men) of all invitees used at least 1 psychotropic medication. Nonparticipation in the 2 arms combined was associated with the use of anxiolytics (60.7% in users vs 43.2% in nonusers; OR=1.53; 95% CI=1.45, 1.62) and antipsychotics (64.3% vs 43.8%; OR=1.41; 95% CI=1.30, 1.53) and increased with higher doses for both drugs. Hypnotics and antidepressants were only weakly associated with nonparticipation in higher doses. Participation rates were 57.3%, 52.3%, 42.9%, and 35.4% in those prescribed 0, 1, 2, and 3-4 classes of psychotropic medications, respectively. The associations between the use of psychotropic medications and nonparticipation were similar for the 2 screening tests.

CONCLUSIONS

These findings show significant disparities in colorectal cancer screening participation for individuals with mental illness, independent of the screening method. Moreover, screening participation varied depending on the type and severity of mental illness. Targeted interventions are warranted to ensure that people with mental illness are supported to access the benefits of colorectal cancer screening.

Abstract PR002: Development and validation of a risk prediction model for post-polypectomy colorectal cancer in 4 prospective US cohorts

Background: Individuals with polypectomy are still at higher risk of developing colorectal cancer than general population and are thus recommended to undergo colonoscopy surveillance for timely detection and prevention of subsequent colorectal cancer. The current clinical guidelines regarding the interval of surveillance are based on weak evidence. There is substantial overuse of surveillance colonoscopy in low-risk individuals and underuse in high-risk individuals. Effective risk stratification tools for post-polypectomy colorectal cancer (PPCRC) are lacking. Methods: Leveraging the integrated endoscopic, histopathologic and epidemiologic data in 3 population-based cohorts (Nurses’ Health Study (NHS) I, II and Health Professionals Follow-up Study (HPFS)), we developed a risk score to predict incident PPCRC among 26,744 patients with a polypectomy between 1986 and 2017. We validated the risk score in the Mass General Brigham (MGB) colonoscopy cohort of 76,603 individuals with a polypectomy between 2005 and 2017. In the MGB cohort, we used the validated natural language processing algorithms to extract detailed histopathologic data and merged them with the endoscopic and other clinical data from the electronic health record systems. The detailed protocol for the cohort development has been published (PMID: 33590405). We used Cox regression to calculate the hazard ratios (HRs) and assessed the discrimination using C-statistics and reclassification using the Net Reclassification Improvement (NRI). Results: During a median follow-up of 12.8 (IQR: 9.3, 16.7) and 5.1 (IQR: 2.7, 7.8) years in the NHS I, II/HPFS and MGB colonoscopy cohorts, we documented 220 and 241 PPCRC cases, respectively. We identified a PPCRC risk score based on 11 predictors. In the validation cohort, the risk score showed a strong association with higher risk of PPCRC (HR for high vs. low, 3.55, 95% CI, 2.59-4.88) and demonstrated a C-statistic (95% CI) of 0.75 (0.70-0.79), and was discriminatory even within the low- and high-risk polyp groups of patients (C-statistic, 0.73 and 0.71, respectively) defined by the current colonoscopy surveillance guidelines, leading to a NRI of 45% for PPCRC patients. Conclusion: We developed and validated a risk stratification model for PPCRC that can be used to guide tailored colonoscopy surveillance.

Citation Format: Markus Dines Knudsen, Liang Wang, Kai Wang, Georgios Polychronidis, Paula Berstad, Kana Wu, Xiaosheng He, Dong Hang, Zhe Fang, Shuji Ogino, Andrew T. Chan, Edward L. Giovannucci, Molin Wang, Mingyang Song. Development and validation of a risk prediction model for post-polypectomy colorectal cancer in 4 prospective US cohorts [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr PR002.

Polish immigrants’ access to colorectal cancer screening in Norway – a qualitative study

Background

The Norwegian colorectal cancer (CRC) screening programme started in May 2022. Inequities in uptake of CRC screening is a concern, and we expect that immigrants are at risk of non-uptake. Immigrants from Poland are the most populous immigrant group in Norway. The purpose of this study was to identify and explore factors that may facilitate Polish immigrants’ access to the Norwegian CRC screening programme.

Material and methods

This study was based on qualitative interviews with ten Polish immigrants in Norway. The participants represented a convenience sample that varied in terms of gender, education, employment, time in Norway, place of residence, Norwegian language skills and ties to the Norwegian-Polish community. We performed thematic content analysis to understand CRC screening from the perspective of Polish immigrants, using transnationalism and Levesque’s conceptualization of accessibility as theoretical frameworks.

Results

We grouped our findings into three themes; “understanding of CRC development and the need to access health care”, “binationalism” and “improving accessibility through information”. Within these themes, various factors influenced the participants’ accessibility to CRC screening, namely knowledge about the screening and about causes, development and prevention of the disease, language, choice of screening country, trust in health personnel’s competence, information needs, methods and sources, as well as participants’ perception of the faecal immunochemical test screening user manual. These factors were further influenced by communication between the Polish community in Norway and Poland, as well as travel between the countries.

Conclusion

We identified several factors that can be targeted with an aim to increase Polish immigrants’ access to the Norwegian CRC screening programme. Effective measures could include increasing cultural competence among health care providers and providing information in Polish through Polish-speaking health care professionals, general practitioners and internet portals used by the Polish-speaking community. Focusing on accessibility in a transnational setting, our findings may be of interest for policy makers and service providers planning preventive health measures for immigrants.

Associations of red and processed meat intake with screen-detected colorectal lesions

Limited data exist regarding the role of meat consumption in early-stage colorectal carcinogenesis. We examined associations of red and processed meat intake with screen-detected colorectal lesions in immunochemical fecal occult blood test (FIT)-positive participants, enrolled in the Norwegian CRCbiome study during 2017-2021, aged 55-77 years. Absolute and energy-adjusted intakes of red and processed meat (combined and individually) were assessed using a validated, semi-quantitative FFQ. Associations between meat intake and screen-detected colorectal lesions were examined using multinomial logistic regression analyses with adjustment for key covariates. Of 1162 participants, 319 presented with advanced colorectal lesions at colonoscopy. High v. low energy-adjusted intakes of red and processed meat combined, as well as red meat alone, were borderline to significantly positively associated with advanced colorectal lesions (OR of 1·24 (95 % CI 0·98, 1·57) and 1·34 (95 % CI 1·07, 1·69), respectively). A significant dose-response relationship was also observed for absolute intake levels (OR of 1·32 (95 % CI 1·09, 1·60) per 100 g/d increase in red and processed meat). For processed meat, no association was observed between energy-adjusted intakes and advanced colorectal lesions. A significant positive association was, however, observed for participants with absolute intake levels ≥ 100 v. < 50 g/d (OR of 1·19 (95 % CI 1·09, 1·31)). In summary, high intakes of red and processed meat were associated with presence of advanced colorectal lesions at colonoscopy in FIT-positive participants. The study demonstrates a potential role of dietary data to improve the performance of FIT-based screening.

Characteristics of non-participants in a randomized colorectal cancer screening trial comparing sigmoidoscopy and faecal immunochemical testing

Public health systems should guarantee universal access to health care services, including cancer screening. We assessed whether certain population subgroups were underrepresented among participants in colorectal cancer screening with sigmoidoscopy and faecal immunochemical testing (FIT). Between 2012 and 2019, about 140 000 individuals aged 50 to 74 years were randomly invited to once‐only sigmoidoscopy or first round of FIT screening. Our study included 46 919 individuals invited to sigmoidoscopy and 70 019 to FIT between 2012 and 2017. We used logistic regression models to evaluate if demographic and socioeconomic factors and use of certain drugs were associated with participation. Twenty‐four thousand one hundred and fifty‐nine (51.5%) individuals attended sigmoidoscopy and 40 931 (58.5%) FIT screening. Male gender, young age, low education and income, being retired or unemployed, living alone, being an immigrant, long driving time to screening centre, and use of antidiabetic and psychotropic drugs were associated with low participation in both screening groups. Many of these factors also predicted low acceptance of colonoscopy after positive FIT. While male gender, young age and living alone were more strongly associated with nonparticipation in FIT than sigmoidoscopy, low education and income, being retired or immigrant and long driving time were more strongly associated with nonparticipation in sigmoidoscopy than FIT. In conclusion, participation was lower in sigmoidoscopy than FIT. Predictors of nonparticipation were similar between arms. However, low socioeconomic status, being an immigrant and long driving time affected participation more in sigmoidoscopy screening, suggesting that FIT may guarantee more equal access to screening services than sigmoidoscopy.

Lifestyle predictors for inconsistent participation to fecal based colorectal cancer screening

BACKGROUND

Consistent participation in colorectal cancer (CRC) screening with repeated fecal immunochemical test (FIT) is important for the success of the screening program. We investigated whether lifestyle risk factors for CRC were related to inconsistent participation in up to four rounds of FIT-screening.

METHOD

We included data from 3,051 individuals who participated in up to four FIT-screening rounds and returned a lifestyle questionnaire. Using logistic regression analyses, we estimated associations between smoking habits, body mass index (BMI), physical activity, alcohol consumption, diet and a healthy lifestyle score (from least favorable 0 to most favorable 5), and inconsistent participation (i.e. not participating in all rounds of eligible FIT screening invitations).

RESULTS

Altogether 721 (24%) individuals were categorized as inconsistent participants Current smoking and BMI ≥30 kg/m² were associated with inconsistent participation; odds ratios (ORs) and 95% confidence intervals (CIs) were 1.54 (1.21-2.95) and 1.54 (1.20-1.97), respectively. A significant trend towards inconsistent participation by a lower healthy lifestyle score was observed (p < 0.05).

CONCLUSIONS

Lifestyle behaviors were associated with inconsistent participation in FIT-screening. Initiatives aimed at increasing participation rates among those with the unhealthiest lifestyle have a potential to improve the efficiency of screening.

Public Awareness and Perceptions of Colorectal Cancer Prevention: a Cross-Sectional Survey

We aimed to investigate awareness of colorectal cancer (CRC) lifestyle risk factors, willingness to participate in CRC screening, and preferences concerning channels for information on CRC prevention in the general population, including the target age of the upcoming Norwegian national CRC screening program. The present study was a cross-sectional online survey of adults aged 39 to 55 years registered as Kantar Web Panel respondents in Norway. The survey included demographic characteristics, multiple choice knowledge questions of lifestyle risk factors for CRC, attitudes towards CRC screening, and preferred channels for receiving information on CRC prevention. Of 4375 participants invited, 2007 (46%) answered the survey. The average number of correctly identified lifestyle risk factors for CRC was 7.3 of ten. Women were significantly more likely than men, and those with university or college education more likely than those with lower education to correctly identify at least eight risk factors (odds ratio, OR = 1.53, 95% confidence interval, CI 1.25-1.87, and OR = 1.51, 95% CI 1.23-1.86, respectively). The number of correctly identified risk factors was positively associated with willingness to participate in CRC screening (P for trend < 0.001). The national public work force and the Norwegian Cancer Society were selected by 76% and 69% of the participants, respectively, to be trustworthy sources of information on CRC prevention. Awareness of CRC risk factors was associated with willingness to participate in CRC screening. The national public work force and Cancer Society can be generally accepted sources of CRC preventive information.

The CRCbiome study: a large prospective cohort study examining the role of lifestyle and the gut microbiome in colorectal cancer screening participants

BACKGROUND

Colorectal cancer (CRC) screening reduces CRC incidence and mortality. However, current screening methods are either hampered by invasiveness or suboptimal performance, limiting their effectiveness as primary screening methods. To aid in the development of a non-invasive screening test with improved sensitivity and specificity, we have initiated a prospective biomarker study (CRCbiome), nested within a large randomized CRC screening trial in Norway. We aim to develop a microbiome-based classification algorithm to identify advanced colorectal lesions in screening participants testing positive for an immunochemical fecal occult blood test (FIT). We will also examine interactions with host factors, diet, lifestyle and prescription drugs. The prospective nature of the study also enables the analysis of changes in the gut microbiome following the removal of precancerous lesions.

METHODS

The CRCbiome study recruits participants enrolled in the Bowel Cancer Screening in Norway (BCSN) study, a randomized trial initiated in 2012 comparing once-only sigmoidoscopy to repeated biennial FIT, where women and men aged 50-74 years at study entry are invited to participate. Since 2017, participants randomized to FIT screening with a positive test result have been invited to join the CRCbiome study. Self-reported diet, lifestyle and demographic data are collected prior to colonoscopy after the positive FIT-test (baseline). Screening data, including colonoscopy findings are obtained from the BCSN database. Fecal samples for gut microbiome analyses are collected both before and 2 and 12 months after colonoscopy. Samples are analyzed using metagenome sequencing, with taxonomy profiles, and gene and pathway content as primary measures. CRCbiome data will also be linked to national registries to obtain information on prescription histories and cancer relevant outcomes occurring during the 10 year follow-up period.

DISCUSSION

The CRCbiome study will increase our understanding of how the gut microbiome, in combination with lifestyle and environmental factors, influences the early stages of colorectal carcinogenesis. This knowledge will be crucial to develop microbiome-based screening tools for CRC. By evaluating biomarker performance in a screening setting, using samples from the target population, the generalizability of the findings to future screening cohorts is likely to be high.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01538550 .

Lifestyle changes and risk of cancer: experience from the Swedish women's lifestyle and health cohort study

BACKGROUND

The impact of lifestyle changes on cancer risk is yet to be elucidated. We investigated this issue in the Swedish Women's Lifestyle and Health Cohort Study.

MATERIAL AND METHODS

We measured changes by comparing two questionnaires, filled in 1991/92 and 2003. We followed women for cancer from 2003 until 2012. We used Cox regression models to assess the effect of changes in smoking, alcohol consumption, body mass index (BMI), physical activity and a lifestyle score on the risk of lifestyle-related cancer. One point was added to the lifestyle score for each of these: non-smoking, alcohol consumption ≤12 grams/day, BMI <25 kg/m2 and high level of physical activity.

RESULTS

We included 29,930 women. From 1991/92 to 2003, median age changed from 40.0 to 51.7 years, alcohol consumption from 2.5 to 4.7 grams/day, BMI from 22.7 to 24.5 kg/m2, proportion of current smokers from 31.0 to 20.6% and women reporting high physical activity from 27.2 to 37.0%. Women who quit smoking had lower risk of smoking-related cancers compared to women who continued (hazard ratio (HR) 0.74, 95% confidence interval (CI) 0.55-1.00). Women who reduced their weight by more than 5%, compared to women with stable weight, had lower risk of breast cancer (HR 0.49, 95% CI 0.31-0.78). Among women with score of 0-2 in 1992/93, those who improved to 3-4 had lower risk of lifestyle-related cancers compared to women who did not (HR 0.81, 95% CI 0.66-0.99).

CONCLUSIONS

Healthy lifestyle changes, particularly smoking cessation and weight reduction, were associated with a decreased risk of cancer.

Colorectal Cancer Screening With Repeated Fecal Immunochemical Test Versus Sigmoidoscopy: Baseline Results From a Randomized Trial

BACKGROUND & AIMS

The comparative effectiveness of sigmoidoscopy and fecal immunochemical testing (FIT) for colorectal cancer (CRC) screening is unknown.

METHODS

Individuals aged 50-74 years living in Southeast Norway were randomly invited between 2012 and 2019 to either once-only flexible sigmoidoscopy or FIT screening every second year. Colonoscopy was recommended after sigmoidoscopy if any polyp of ≥10 mm, ≥3 adenomas, any advanced adenomas, or CRC was found or, subsequent to, FIT >15 μg hemoglobin/g feces. Data for this report were obtained after complete recruitment in both groups and included 2 full FIT rounds and part of the third round. Outcome measures were participation, neoplasia detection, and adverse events. Age-standardized detection rates and age-adjusted odds ratios (ORs) were calculated.

RESULTS

We included 139,291 individuals: 69,195 randomized to sigmoidoscopy and 70,096 to FIT. The participation rate was 52% for sigmoidoscopy, 58% in the first FIT round, and 68% for 3 cumulative FIT rounds. Compared to sigmoidoscopy, the detection rate for CRC was similar in the first FIT round (0.25% vs 0.27%; OR, 0.92; 95% confidence interval [CI], 0.75-1.13) but higher after 3 FIT rounds (0.49% vs 0.27%; OR, 1.87; 95% CI, 1.54-2.27). Advanced adenoma detection rate was lower in the first FIT round compared to sigmoidoscopy at 1.4% vs 2.4% (OR, 0.57; 95% CI, 0.53-0.62) but higher after 3 cumulative FIT rounds at 2.7% vs 2.4% (OR, 1.14; 95% CI, 1.05-1.23). There were 33 (0.05%) serious adverse events in the sigmoidoscopy group compared to 47 (0.07%) in the FIT group (P = .13).

CONCLUSIONS

Participation was higher and more CRC and advanced adenomas were detected with repeated FIT compared to sigmoidoscopy. The risk of perforation and bleeding was comparable. Clinicaltrials.gov, Number: NCT01538550.

Exploring geographical differences in the incidence of colorectal cancer in the Norwegian Women and Cancer Study: a population-based prospective study

Purpose

Norway has experienced an unexplained, steep increase in colorectal cancer (CRC) incidence in the last half-century, with large differences across its counties. We aimed to determine whether geographical distribution of lifestyle-related CRC risk factors can explain these geographical differences in CRC incidence in Norwegian women.

Methods

We followed a nationally representative cohort of 96,898 women with self-reported information on lifestyle-related CRC risk factors at baseline and at follow-up 6-8 years later in the Norwegian Women and Cancer Study. We categorized Norwegian counties into four county groups according to CRC incidence and used Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk factors. We used the Karlson, Holm, and Breen (KHB) method of mediation analysis to investigate the extent to which the risk factors accounted for the observed differences in CRC incidence between counties.

Results

During an average of 15.5 years of follow-up, 1875 CRC cases were diagnosed. Height (HR=1.12; 95% CI 1.08, 1.17 per 5 cm increase); being a former smoker who smoked ≥10 years (HR=1.34; 95% CI 1.15, 1.57); or being a current smoker who has smoked for ≥10 years (HR=1.28; 95% CI 1.12, 1.46) relative to never smokers was associated with increased CRC risk. Duration of education >12 years (HR=0.78; 95% CI 0.69, 0.87) vs ≤12 years, and intake of vegetables and fruits >300 g (HR=0.90; 95% CI 0.80, 0.99) vs ≤300 g per day were associated with reduced CRC risk. However, these risk factors did not account for the differences in CRC risk between geographical areas of low and high CRC incidence. This was further confirmed by the KHB method using baseline and follow-up measurements (b=0.02, 95% CI -0.02, 0.06, p=0.26).

Conclusion

Lifestyle-related CRC risk factors did not explain the geographical variations in CRC incidence among Norwegian women. Possible residual explanations may lie in heritable factors.

Improving Cancer Preventive Behaviors: A Randomized Trial of Tailored Lifestyle Feedback in Colorectal Cancer Screening

BACKGROUND

Cancer screening provides an opportunity to increase awareness of cancer-preventive lifestyle behaviors such as nonsmoking, physical activity, low alcohol consumption, and a healthy diet. We tested the effect of standardized, individually tailored written feedback (TF), and a standard leaflet (SL) on 1-year lifestyle behaviors in a colorectal cancer screening setting.

METHODS

A total of 3,642 men and women aged 50-74 years invited to sigmoidoscopy screening were randomly assigned to: (i) TF; (ii) SL for cancer-preventive lifestyle behaviors; or (iii) control. Participants were mailed two self-reported lifestyle questionnaires (LSQ) 1 year apart. The TF intervention was based on the prescreening LSQ answers. We analyzed differences [with 95% confidence intervals (CI)] by comparing prescreening to 1-year follow-up of single cancer-preventive factors and the number of cancer-preventive lifestyle behaviors (range 0-4) between the groups by multivariable logistic regression and analysis of covariance (ANCOVA).

RESULTS

A total of 1,054 screening participants without neoplastic findings (29% of those invited to screening) were included in this study. Participants in the TF group increased their number of cancer-preventive lifestyle behaviors significantly compared with those in the control group by 0.11 (95% CI, 0.02 to 0.19). Overweight/obese individuals in the TF group had a -0.84 kg (95% CI, -1.47 to -0.22) larger reduction in body weight compared with the control group.

CONCLUSIONS

TF at sigmoidoscopy screening led to small improvements in cancer-preventive behaviors.

IMPACT

Colorectal cancer screening is a suitable setting for increasing awareness of cancer-preventive behavior.

Exploring the effect of a lifestyle intervention on cancer risk: 43-year follow-up of the randomized Oslo diet and antismoking study

BACKGROUND/OBJECTIVES

The Oslo diet and antismoking study showed that counselling for a healthy lifestyle reduced lifelong coronary mortality in high-risk men. We explored whether the same counselling reduced also cancer risk.

METHODS

The study randomly allocated males at high coronary risk to either a 5-year intervention for lifestyle changes (cholesterol-lowering dietary changes, weight loss and stopping smoking) or a control group (1 : 1) in 1972/73. We explored the incidence and mortality of all cancers and cancer forms related to smoking, BMI or diet up to 43 years after randomization.

RESULTS

A total of 595 men in the intervention and 621 in the control group were included. At inclusion median age was 45 years, 588 (48.4%) subjects were overweight (BMI > 25 kg m^-2 ) and 925 (76.1%) current smokers. The intervention did not reduce the risk of cancer after 43 years (adjusted hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.80-1.15). In the first 25 years of follow-up, among the 1088 (89.5%) men who were overweight/obese and/or smokers, the intervention reduced the incidence of those cancer forms related to smoking, BMI or diet (including carcinoma of the respiratory, digestive and urinary tracts; adjusted HR 0.69; 95% CI 0.49-0.99). The intervention had no significant effect on incidence beyond 25 years, or on mortality.

CONCLUSIONS

The 5-year counselling for a healthy lifestyle did not reduce the overall cancer risk in the very long term. However, in the first 25 years, the counselling reduced the risk of relevant cancer types in overweight/obese subjects and smokers.

Acceptability of two colorectal cancer screening tests: pain as a key determinant in sigmoidoscopy

Background Participants' experience with a screening test can influence adherence, and therefore the efficacy of screening programs. We compared screening with unsedated flexible sigmoidoscopy and fecal immunochemical testing (FIT) for participants' satisfaction with the decision and for willingness to repeat colorectal cancer screening. Methods In a prospective, randomized trial 3257 individuals (50 - 74 years) were invited to either flexible sigmoidoscopy or FIT (1:1), of whom 1650 took up the offer (52.6 %). In total, 1497 screening participants completed at least one questionnaire, either before screening, and/or at three time points in the following year, that measured willingness to repeat screening, willingness to recommend screening, and satisfaction with decision to attend. There were 769 and 728 responders in the flexible sigmoidoscopy and FIT group, respectively. Additionally, 581 flexible sigmoidoscopy participants also completed a pain questionnaire. Results 1 year later, 10 % of the flexible sigmoidoscopy participants were not willing to repeat screening, compared to 5 % of FIT participants. A higher percentage of women compared to men would not repeat flexible sigmoidoscopy screening (adjusted odds ratio [OR] 2.52, 95 % confidence interval [95 %CI] 1.48 to 4.28). Notably, 22 % of women reported pain during flexible sigmoidoscopy compared to 5 % of men. When we added pain to the statistical model, pain was significantly associated with unwillingness to repeat flexible sigmoidoscopy (OR 3.15, 95 %CI 1.68 to 5.87), while gender was no longer associated (OR 1.53, 95 %CI 0.82 to 2.88). Conclusion Acceptability for flexible sigmoidoscopy and for FIT was high among Norwegian screening participants, though FIT participants were more willing to repeat screening. Women were less willing to repeat screening with flexible sigmoidoscopy compared to men. This gender difference seemed partly due to pain, and therefore preventable.This study is registered at ClinicalTrials.gov: NCT01538550.

Lifestyle predictors for non-participation and outcome in the second round of faecal immunochemical test in colorectal cancer screening

BACKGROUND

To reduce colorectal cancer (CRC) mortality through population-based screening programmes using faecal tests, it is important that individuals continue to participate in the repeated rounds of screening. We aimed to identify lifestyle predictors for discontinuation of faecal immunochemical test (FIT) screening after the first round, as well as lifestyle predictors for colorectal neoplasia detected in the second-round FIT screening.

METHODS

In this longitudinal study, we invited 6959 individuals aged 50-74 years from south-east Norway for a first round of FIT screening and to complete a self-reported lifestyle questionnaire on demographic factors, body mass index (BMI, kg m-2), smoking habits, physical activity, consumption of alcohol and dietary items. Two years later, we estimated the associations between these factors, non-participation and screening results in the second round of FIT screening using adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Of the 3114 responders to the questionnaire who completed the first-round FIT and who were invited to participate in second-round FIT screening, 540 (17%) did not participate. The OR and (95% CI) for discontinuation of FIT screening after the first round was 1.61 (1.24-2.10) for current smoking compared with non-smoking; 2.01 (1.25-3.24) for BMI⩾35 kg m-2 compared with BMI 16.9-24.9 kg m-2 and 0.70 (0.52-0.94) for physical activity in the third quartile vs the first. Among participants, smoking, high BMI and high alcohol consumption were associated with an increased odds of detecting colorectal neoplasia (n=107).

CONCLUSIONS

These results may indicate that Norwegian FIT screening participants who discontinue after the first round have lifestyle behaviours associated with increased risk of CRC.

Psychological effects of colorectal cancer screening: Participants vs individuals not invited

AIM

To investigate the possible long-term psychological harm of participating in colorectal cancer (CRC) screening in Norway.

METHODS

In a prospective, randomized trial, 14294 participants (aged 50-74 years) were invited to either flexible sigmoidoscopy (FS) screening, or a faecal immunochemical test (FIT) (1:1). In total, 4422 screening participants (32%) completed the questionnaire, which consisted of the Hospital Anxiety and Depression Scale and the SF-12, a generic health-related quality of life (HRQOL) measurement, when invited to screening and one year after the invitation. A control group of 7650 individuals was invited to complete the questionnaire only, at baseline and one year after, and 1911 (25%) completed the questionnaires.

RESULTS

Receiving a positive or negative screening result and participating in the two different screening modalities did not cause clinically relevant mean changes in anxiety, depression or HRQOL after one year. FS screening, but not FIT, was associated with an increased probability of being an anxiety case (score ≥ 8) at the one-year follow-up (5.6% of FS participants transitioned from being not anxious to anxious, while 3.0% experienced the reverse). This increase was moderately significantly different from the changes in the control group (in which the corresponding numbers were 4.8% and 4.5%, respectively), P = 0.06.

CONCLUSION

Most individuals do not experience psychological effects of CRC screening participation after one year, while FS participation is associated with increased anxiety for a smaller group.

Favorable lifestyle before diagnosis associated with lower risk of screen-detected advanced colorectal neoplasia

AIM

To investigate the association between adherence to health recommendations and detection of advanced colorectal neoplasia (ACN) in colorectal cancer (CRC) screening.

METHODS

A total of 14832 women and men were invited to CRC screening, 6959 in the fecal immunochemical test arm and 7873 in the flexible sigmoidoscopy arm. These were also sent a self-reported lifestyle questionnaire to be completed prior to their first CRC screening. A lifestyle score was created to reflect current adherence to healthy behaviors in regard to smoking, body mass index, physical activity, alcohol consumption and food consumption, and ranged from zero (poorest) to six (best). Odds ratios (ORs) and 95%CIs were calculated using multivariable logistic regression to evaluate the association between the single lifestyle variables and the lifestyle score and the probability of detecting ACN.

RESULTS

In all 6315 women and men completed the lifestyle questionnaire, 3323 (53%) in the FIT arm and 2992 (47%) in the FS arm. This was 89% of those who participated in screening. ACN was diagnosed in 311 (5%) participants of which 25 (8%) were diagnosed with CRC. For individuals with a lifestyle score of two, three, four, and five-six, the ORs (95%CI) for the probability of ACN detection were 0.82 (0.45-1.16), 0.43 (0.28-0.73), 0.41 (0.23-0.64), and 0.41 (0.22-0.73), respectively compared to individuals with a lifestyle score of zero-one. Of the single lifestyle factors, adherence to non-smoking and moderate alcohol intake were associated with a decreased probability of ACN detection compared to being a smoker or having a high alcohol intake 0.53 (0.42-0.68) and 0.63 (0.43-0.93) respectively.

CONCLUSION

Adopted healthy behaviors were inversely associated with the probability of ACN detection. Lifestyle assessment might be useful for risk stratification in CRC screening.

Lifestyle changes at middle age and mortality: a population-based prospective cohort study

BACKGROUND

The effect of modifying lifestyle at middle age on mortality has been sparsely examined.

METHODS

Men and women aged 50-54 years randomised to the control group (no intervention) in the population-based Norwegian Colorectal Cancer Prevention trial were asked to fill in lifestyle questionnaires in 2001 and 2004. Lifestyle scores were estimated ranging from 0 (poorest) to 4 (best) based on health recommendations (non-smoking, daily physical activity, body mass index <25.0 kg/m² and healthy diet). Outcomes were all-cause, cancer and cardiovascular mortality before 31 December 2013.

RESULTS

Of the 6886 attainable individuals included in the study, 4211 (61%) responded to the baseline questionnaire in 2001. After a median follow-up of 12.3 years, 226 (5.4%) of the baseline questionnaire responders died; 110 (49%) from cancer and 32 (14%) from cardiovascular disease. For each increment in lifestyle score in 2001, a 21% lower all-cause mortality was observed (HR 0.79, 95% CI 0.67 to 0.94, adjusted for age, sex, occupational working hours and chronic disease or pain during 3 years before enrolment). A one-point increase in lifestyle score from 2001 to 2004 was associated with a 38% reduction in all-cause mortality (adjusted HR 0.62, CI 0.45 to 0.84). The group reporting lifestyle change from score 0-1 (unfavourable) in 2001 to score 2-4 (favourable) in 2004 had 4.8 fewer deaths per 1000 person years, compared with the group maintaining an 'unfavourable' lifestyle (adjusted HR 0.31, CI 0.13 to 0.70 for all-cause mortality).

CONCLUSIONS

Favourable lifestyle changes at age 50-60 years may prevent early death.

TRIAL REGISTRATION

NCT00119912; pre-results.

Do no harm: no psychological harm from colorectal cancer screening

Background:

Participation in cancer screening programmes might cause worries in the population outweighting the benefits of reduced mortality. The present study aimed to investigate possible psychological harm of participation in a colorectal cancer (CRC) screening pilot in Norway.

Methods:

In a prospective, randomised trial participants (aged 50–74 years) were invited to either flexible sigmoidoscopy (FS) screening, faecal immunochemical test (FIT), or no screening (the control group; 1 : 1: 1). Three thousand two hundred and thirteen screening participants (42% of screened individuals) completed the Hospital Anxiety and Depression Scale questionnaire as well as the SF-12—a health-related quality of life (HRQOL) questionnaire when invited to screening and when receiving the screening result. A control group was invited to complete the questionnaires only. Two thousand six hundred and eighteen control participants (35% of invited individuals) completed the questionnaire.

Results:

A positive screening result did not increase participants' level of anxiety or depression, or decrease participants' level of HRQOL. Participants who received a negative result reported decreased anxiety and improvement on some HRQOL dimensions. However, no change was considered to be of clinical relevance.

Conclusion:

The current study showed no clinically relevant psychological harm of receiving a positive CRC screening result or of participating in FS or FIT screening, in a Norwegian population.

Long-term lifestyle changes after colorectal cancer screening: randomised controlled trial

OBJECTIVE

There is uncertainty whether cancer screening affects participant incentives for favourable lifestyle. The present study investigates long-term effects of colorectal cancer (CRC) screening on lifestyle changes.

DESIGN

In 1999-2001, men and women drawn from the population registry were randomised to screening for CRC by flexible sigmoidoscopy ('invited-to-screening' arm) or to no-screening (control arm) in the Norwegian Colorectal Cancer Prevention trial. A subgroup of 3043 individuals in the 'invited-to-screening' and 2819 in the control arm, aged 50-55 years, randomised during 2001 had their lifestyle assessed by a questionnaire at inclusion and after 11 years (42% of cohort). The outcome was 11-year changes in lifestyle factors (body weight, smoking status, physical exercise, selected dietary habits) and in total lifestyle score (0-4 points, translating to the number of lifestyle recommendations adhered to). We compared outcomes in the two randomisation arms and attendees with positive versus negative findings.

RESULTS

Total lifestyle scores improved in both arms. The improvement was smaller in the 'invited-to-screening' arm (score 1.43 at inclusion; 1.58 after 11 years) compared with the control arm (score 1.49 at inclusion; 1.67 after 11 years); adjusted difference -0.05 (95% CI -0.09 to -0.01; p=0.03). The change in the score was less favourable in screening attendees with a positive compared with negative screening result; adjusted difference -0.16 (95% CI -0.25 to -0.08; p<0.001).

CONCLUSIONS

The present study suggests that possible unfavourable lifestyle changes after CRC screening are modest. Lifestyle counselling may be considered as part of cancer screening programmes.

TRIAL REGISTRATION NUMBER

NCT00119912.

Effect of different degrees of hydrogenated fish oil on intestinal carcinogenesis in Min/+ mice

Intake of trans fatty acids from hydrogenated fish oils has been related to increased risk of coronary heart diseases. The possible effect on colorectal carcinogenesis is unclear.

MATERIALS AND METHODS

Multiple intestinal neoplasia (Min/+) mice were fed one of four experimental diets: either raw fish oil (FO), low (LHFO)-, high (HHFO)- or fully-hydrogenated fish oil (FFHO), from 0 to 9 weeks of age. The number and size of intestinal tumors were recorded.

RESULTS

There was no difference between the intervention groups in the numbers of developed intestinal tumors. The tumor size was statistically significantly lower in HHFO vs. the FO-group in male Min/+ mice. The HHFO and FHFO groups had lower weight gain than did the FO group (p=0.008 and p=0.04, respectively), but gender differences, due to effect of dietary intervention on weight gain, were found in Min/+ mice.

CONCLUSION

When compared with raw fish oil, different degrees of hydrogenation of the fish oil had no effect on intestinal carcinogenesis in Min/+ mice.

Preoperative body size and composition, habitual diet, and post-operative complications in elective colorectal cancer patients in Norway

BACKGROUND

Both malnutrition and obesity are related to worsened post-operative outcomes after colorectal surgery. Obese cancer patients may be malnourished as a result of short-term weight loss. The present study aimed to evaluate preoperative nutritional status, body composition and dietary intake related to post-operative complications (POC) and post-operative hospital days (POHD) in elective colorectal cancer (CRC) patients.

METHODS

Anthropometry, body composition measured by bioelectric spectroscopy and dietary habits assessed by a validated food-frequency questionnaire were examined in 100 newly-diagnosed CRC patients. Data from 30-day POC and POHD were collected from medical records. Nonparametric and chi-squared tests and logistic regression were used to analyse associations between body and dietary variables and post-operative outcome.

RESULTS

Twenty-nine patients had at least one POC. The median POHD was six. Body size and composition measures and short-term weight loss were no different between patients with and without POC, or between patients with POHD <7 and ≥7. Dietary variables were otherwise no different between patients with and without POC, although the median intake of marine n-3 polyunsaturated fatty acids (PUFA, the sum of eicosapentaenoic and docosahexaenoic acids) was significantly lower in patients with versus without POC (0.7 versus 1.2 g day(-1) , P = 0.04).

CONCLUSIONS

We found that preoperative body size, body composition and short-term weight loss were not related to 30-day post-operative outcomes in CRC patients. A high content of marine n-3 PUFA in preoperative habitual diets may protect against POC after CRC surgery.

A case-control study of body mass index and breast cancer risk in white and African-American women

OBJECTIVE

Large body size has been associated with decreased risk of breast cancer in premenopausal women but with increased risk in postmenopausal women. Limited information is available about African-American women and differences by estrogen and progesterone receptor status.

METHODS

We analyzed data from the Women's Contraceptive and Reproductive Experiences Study among 3,997 white and African-American breast cancer case patients diagnosed in 1994 to 1998 and 4,041 control participants ages 35 to 64 years. We calculated multivariate odds ratios (OR) as measures of relative risk of breast cancer associated with self-reported body mass index (BMI) at age 18 and 5 years before diagnosis (recent BMI).

RESULTS

Risk tended to decrease with increasing BMI at age 18 years in all women [OR(BMI > or = 25 kg/m(2) versus < 20 kg/m(2)) = 0.76; 95% confidence interval (CI), 0.63-0.90; P(trend) = 0.005] and with recent BMI in premenopausal women (OR(BMI > or = 35 kg/m(2) versus < 25 kg/m(2)) = 0.81; 95% CI, 0.61-1.06; P(trend) = 0.05), unmodified by race. Among postmenopausal white but not African-American women, there was an inverse relation between recent BMI and risk. High recent BMI was associated with increased risk of estrogen receptor- and progesterone receptor-positive tumors among postmenopausal African-American women (OR(BMI > or = 35 kg/m(2) versus < 25 kg/m(2)) = 1.83; 95% CI, 1.08-3.09; P(trend) = 0.03).

CONCLUSION

Among women at age 35 to 64 years, BMI at age 18 years is inversely associated with risk of breast cancer, but association with recent BMI varies by menopause status, race, and hormone receptor status.

IMPACT

Our findings indicate that studies of BMI and breast cancer should consider breast cancer subtypes.

Dietary sources of vitamin B-12 and their association with plasma vitamin B-12 concentrations in the general population: the Hordaland Homocysteine Study

BACKGROUND

Limited information is available on the association between vitamin B-12 status and intake from different dietary sources.

OBJECTIVE

We investigated the relation of dietary intake of different food items with plasma vitamin B-12 concentrations in the general population.

DESIGN

A cross-sectional, population-based study of 5937 subjects in 2 age groups (47-49 and 71-74 y) from the Hordaland Homocysteine Study in Norway was conducted by using a food-frequency questionnaire and measurements of plasma vitamin B-12 concentrations.

RESULTS

A significant difference in plasma vitamin B-12 concentrations was observed with increasing total vitamin B-12 intake. A plateau was reached at an intake of approximately 10 microg/d. Plasma vitamin B-12 was associated with intakes of increasing amounts of vitamin B-12 from dairy products or fish (P for trend <0.001 for both) but not with intakes of vitamin B-12 from meat or eggs. For the same content of vitamin B-12, intake from dairy products led to the greatest increase in plasma vitamin B-12. Total intake of vitamin B-12, particularly from milk and fish, decreased the risk of vitamin B-12 concentrations <200 pmol/L and impaired vitamin B-12 function (vitamin B-12 <200 pmol/L and methylmalonic acid >0.27 micromol/L) in the total group and in 71-74-y-old subjects.

CONCLUSIONS

Dietary intake of dairy products and fish are significant contributors to plasma vitamin B-12 and may improve plasma vitamin B-12 status. Vitamin B-12 appears to be more bioavailable from dairy products; guidelines for improving vitamin B-12 status should take this into consideration.

Dietary predictors of plasma total homocysteine in the Hordaland Homocysteine Study

Established dietary predictors of plasma total homocysteine (tHcy) include folate, riboflavin, and vitamins B6and B12, while information is scarce regarding other dietary components. The aim of this study was to examine the relation between a variety of food groups, food items and nutrients, and plasma tHcy in a large population-based study. The study population included 5812 men and women aged 47–49 and 71–74 years who completed a 169-item FFQ. tHcy was examined across quartiles of dietary components by multiple linear regression analyses adjusting for age, sex, energy intake, various risk factors for elevated tHcy, as well as for dietary and plasma B-vitamins. Among 4578 non-users of vitamin supplements, intake of vegetables, fruits, cereals, eggs, fish and milk, as well as chicken and non-processed meats were inversely associated with tHcy level. The estimated mean difference in tHcy per increasing quartile of intake ranged from − 0·11 (95 % CI − 0·21, − 0·01) μmol/l for milk to − 0·32 (95 % CI − 0·42, − 0·22) μmol/l for vegetables. Positive associations were found for sweets and cakes. Whole-grain bread was significantly inversely related to tHcy only after additional adjustment for dietary and plasma B-vitamins. The nutrients folate, vitamin B6, B12, and riboflavin were inversely related to tHcy. Complex carbohydrates were inversely, and fat positively associated with tHcy, also after adjustment for dietary and plasma B-vitamins. In conclusion, food items rich in B-vitamins and with a low content of fat and sugar were related to lower tHcy levels. Eggs, chicken, non-processed meat, fish and milk were inversely associated with tHcy.

Dietary fat and plasma total homocysteine concentrations in 2 adult age groups: the Hordaland Homocysteine Study

BACKGROUND

The intake of n-3 (formerly called omega-3) fatty acids (FAs) may be inversely associated with plasma total homocysteine (tHcy) concentrations, but the epidemiologic data are sparse.

OBJECTIVE

We examined the association between dietary fat and tHcy in a Norwegian population.

DESIGN

A cross-sectional, population-based study of 5917 subjects in 2 age groups (47-49 and 71-74 y old) was conducted with the use of food-frequency questionnaires and measurement of plasma tHcy concentrations.

RESULTS

The intake of saturated FAs (SFAs) was positively and significantly (P for trend < 0.001) associated with tHcy concentrations; the difference in plasma tHcy concentrations between the highest and lowest quartiles of SFAs was 8.8%. The intake of marine very-long-chain n-3 FAs was inversely associated with tHcy concentrations; the difference in plasma tHcy concentrations between the lowest and the highest quartiles was -5.0% (P for trend < 0.001). Intakes of total and monounsaturated fat also were positively associated with plasma tHcy concentrations (P for trend < 0.001 and < 0.005, respectively), whereas the intake of polyunsaturated fat was positively associated with tHcy concentrations only in the younger subjects (P for trend = 0.03). The associations were weakened by additional adjustment for B vitamin intake but remained significant for SFA intake (P < 0.001). When stratified for total B vitamin intake, the inverse association between tHcy concentrations and very-long-chain n-3 FAs was significant only in the highest quartile of B vitamin intake (P for trend = 0.001), regardless of supplement use.

CONCLUSIONS

High intakes of SFAs are associated with high plasma concentrations of tHcy. The inverse association between dietary intakes of very-long-chain n-3 FAs and plasma tHcy concentrations is apparent only at high B vitamin intakes.

Alcohol intake and breast cancer risk among young women

INTRODUCTION

Alcohol intake has been consistently associated with breast cancer risk, but the importance of timing of intake and the impact of beverage type are unclear.

METHODS

We evaluated whether early, lifetime or recent alcohol intake was associated with breast cancer risk, and whether risk varied by type of alcoholic drinks in 1,728 newly diagnosed population-based breast cancer patients and 435 control subjects aged 20-49 years. We used multivariable logistic regression models to estimate odds ratios (OR) and 95% confidence intervals (CI) as measures of the relative risk of breast cancer associated with intake of alcoholic drinks.

RESULTS

Intake of alcoholic drinks during the recent five year period before the breast cancer diagnosis was associated with increased breast cancer risk (P (trend) = 0.04). Intake of two or more alcoholic drinks per day during this five year period was associated with an 82% increase in breast cancer risk relative to never drinkers (OR = 1.82, 95% CI = 1.01-3.28). No risk increase was observed for alcohol intake at ages 15-20 years or for lifetime alcohol intake. Risk did not vary by type of alcohol consumed.

CONCLUSIONS

Our results suggest that recent alcohol consumption may be associated with increased breast cancer risk in young women.

Influence of long-term intervention with dietary counseling, long-chain n-3 fatty acid supplements, or both on circulating markers of endothelial activation in men with long-standing hyperlipidemia

BACKGROUND

Dietary factors and very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) may influence the atherothrombotic process. Elevated concentrations of circulating cell adhesion molecules, thrombomodulin (TM), von Willebrand factor (vWF), and tissue-type plasminogen activator antigen (tPAag) are related to atherothrombotic cardiovascular disease.

OBJECTIVE

The randomized Diet and Omega-3 Intervention Trial (DOIT) targeted a comparison of the effect of 3-y dietary counseling, n-3 PUFA supplementation (2.4 g/d), or both on circulating markers of endothelial activation.

DESIGN

The study included 563 elderly men with long-standing hyperlipidemia. The men were randomly assigned by factorial design into 4 groups: control (no dietary counseling and placebo capsules), dietary counseling (and placebo capsules), n-3 PUFA supplementation (no dietary counseling), and dietary counseling and n-3 PUFA supplementation.

RESULTS

Serum concentrations of fatty acids reflected good compliance. Dietary counseling was followed by significantly reduced concentrations of soluble intercellular adhesion molecule 1 (sICAM-1; P < 0.001), sTM (P = 0.004), and tPAag (P < 0.001) than in subjects without dietary counseling. After n-3 PUFA supplementation, significantly reduced concentrations of sICAM-1 (P < 0.001) and sTM (P = 0.006) were observed when compared with subjects receiving placebo capsules. An increase in tPAag was not significantly different from that observed in subjects receiving placebo capsules. For sICAM-1, a significant effect was observed for both interventions combined.

CONCLUSIONS

Each intervention (dietary counseling or n-3 PUFA supplements) reduced sTM and sICAM-1 concentrations, indicating decreased endothelial activation. The tPAag increase in the groups not receiving dietary counseling (pooled), which indicates progression of atherosclerosis, was significantly counteracted by dietary counseling.

Supplementation with fish oil affects the association between very long-chain n-3 polyunsaturated fatty acids in serum non-esterified fatty acids and soluble vascular cell adhesion molecule-1

We have investigated the effect of fish oil supplementation on the association between serum non-esterified fatty acid (NEFA) pattern and atherosclerotic activity. We studied correlations between serum non-esterified very long-chain eicosapentaenoic (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA) and biochemical markers of endothelial activation before and after 18-months intervention with fish oil supplementation. The fish oil supplementation consisted of 2.4 g of EPA and DHA per day, with corn oil as placebo. Elderly men ( n =171) with high risk for coronary heart disease were divided into four intervention groups in a factorial design: fish oil supplementation ( n =44), dietary intervention ( n =42), fish oil supplementation+dietary intervention ( n =47) or placebo ( n =38). The composition of fasting NEFA was analysed before and after intervention by GLC. Circulating endothelial markers were analysed by ELISA. A statistically significant positive correlation between the change in serum non-esterified DHA and soluble vascular cell adhesion molecule-1 (sVCAM-1) was found in the pooled group that received fish oil supplementation ( n =91; Spearman's correlation coefficient r =0.24, P =0.02). No such correlation was found in the pooled group without fish oil supplementation ( n =80). Furthermore, there was a significant negative correlation between the change in serum non-esterified EPA and the relative change in sVCAM-1 in the group that did not receive fish oil supplementation ( r =-0.34, P =0.002). No such correlation was found in the group with fish oil supplementation. We conclude that large increase in serum non-esterified EPA and DHA, which can only be attained by supplementation, might increase inflammation in vascular endothelium. A moderate dietary increase in fish oil intake may, however, have an effect on decreasing inflammatory markers.