Dataset Information

Dietary, lifestyle and clinicopathological factors associated with BRAF and K-ras mutations arising in distinct subsets of colorectal cancers in the EPIC Norfolk study.

ABSTRACT:

Background

BRAF and K-ras proto-oncogenes encode components of the ERK signalling pathway and are frequently mutated in colorectal cancer. This study investigates the associations between BRAF and K-ras mutations and clinicopathological, lifestyle and dietary factors in colorectal cancers.

Methods

186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for BRAF and K-ras mutations. Diet and lifestyle data were collected prospectively using seven day food diaries.

Results

BRAF V600E mutation was found in 15.6% of colorectal cancers but at higher frequencies in cancers with proximal location, poor differentiation and microsatellite instability (MSI) (all p < 0.001). K-ras mutation (mostly in codons 12 and 13) was found in 22.0% of colorectal cancers but at higher frequencies in cancers of more advanced Dukes' stage (p = 0.001), microsatellite stable (MSS) status (p = 0.002) and in individuals with lower blood high-density lipoprotein concentrations (p = 0.04). Analysis of dietary factors demonstrated no link between BRAF mutation and any specific dietary constituent, however, K-ras mutation was found at higher frequencies in individuals with higher white meat consumption (p < 0.001). Further analysis of specific mutation type demonstrated that G to A transitions in K-ras were observed at higher frequencies in individuals consuming lower amounts of fruit (p = 0.02).

Conclusion

These data support the model of BRAF and K-ras mutations arising in distinct colorectal cancer subsets associated with different clinicopathological and dietary factors, acting as mutually exclusive mechanisms of activation of the same signalling pathway.

SUBMITTER: Naguib A

PROVIDER: S-EPMC2847960 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundThe ageing population and prevalence of long-term disorders with multimorbidity are a major health challenge worldwide. The associations between comorbid conditions and mortality risk are well established; however, few prospective community-based studies have reported on prior risk factors for incident hospital admissions with multimorbidity. We aimed to explore the independent associations for a range of demographic, lifestyle and physiological determinants and the likelihood of subsequent hospital incident multimorbidity.MethodsWe examined incident hospital admissions with multimorbidity in 25 014 men and women aged 40-79 in a British prospective population-based study recruited in 1993-1997 and followed up until 2019. The determinants of incident multimorbidity, defined as Charlson Comorbidity Index ≥3, were investigated using multivariable logistic regression models for the 10-year period 1999-2009 and repeated with independent measurements in a second 10-year period 2009-2019.ResultsBetween 1999 and 2009, 18 179 participants (73% of the population) had a hospital admission. Baseline 5-year and 10-year incident multimorbidities were observed in 6% and 12% of participants, respectively. Age per 10-year increase (OR 2.19, 95% CI 2.06 to 2.33) and male sex (OR 1.32, 95% CI 1.19 to 1.47) predicted incident multimorbidity over 10 years. In the subset free of the most serious diseases at baseline, current smoking (OR 1.86, 95% CI 1.60 to 2.15), body mass index >30 kg/m² (OR 1.48, 95% CI 1.30 to 1.70) and physical inactivity (OR 1.16, 95% CI 1.04 to 1.29) were positively associated and plasma vitamin C (a biomarker of plant food intake) per SD increase (OR 0.86, 95% CI 0.81 to 0.91) inversely associated with incident 10-year multimorbidity after multivariable adjustment for age, sex, social class, education, alcohol consumption, systolic blood pressure and cholesterol. Results were similar when re-examined for a further time period in 2009-2019.ConclusionAge, male sex and potentially modifiable lifestyle behaviours including smoking, body mass index, physical inactivity and low fruit and vegetable intake were associated with increased risk of future incident hospital admissions with multimorbidity.

Project description:BackgroundHeavy drinkers of alcohol are reported to use hospitals more than non-drinkers, but it is unclear whether light-to-moderate drinkers use hospitals more than non-drinkers.ObjectiveWe examined the relationship between alcohol consumption in 10,883 men and 12,857 women aged 40-79 years in the general population and subsequent admissions to hospital and time spent in hospital.MethodsParticipants from the EPIC-Norfolk prospective population-based study were followed for ten years (1999-2009) using record linkage.ResultsCompared to current non-drinkers, men who reported any alcohol drinking had a lower risk of spending more than twenty days in hospital multivariable adjusted OR 0.80 (95%CI 0.68-0.94) after adjusting for age, smoking status, education, social class, body mass index and prevalent diseases. Women who were current drinkers were less likely to have any hospital admissions multivariable adjusted OR 0.84 (95%CI 0.74-0.95), seven or more admissions OR 0.77 (95% CI 0.66-0.88) or more than twenty hospital days OR 0.70 (95%CI 0.62-0.80). However, compared to lifelong abstainers, men who were former drinkers had higher risk of any hospital admissions multivariable adjusted OR 2.22 (95%CI 1.51-3.28) and women former drinkers had higher risk of seven or more admissions OR 1.30 (95%CI 1.01-1.67).ConclusionCurrent alcohol consumption was associated with lower risk of future hospital usage compared with non-drinkers in this middle aged and older population. In men, this association may in part be due to whether former drinkers are included in the non-drinker reference group but in women, the association was consistent irrespective of the choice of reference group. In addition, there were few participants in this cohort with very high current alcohol intake. The measurement of past drinking, the separation of non-drinkers into former drinkers and lifelong abstainers and the choice of reference group are all influential in interpreting the risk of alcohol consumption on future hospitalisation.

Project description:Studies have reported a higher mortality risk associated with weight loss, particularly in middle-aged and older adults, although some of these studies did find that gaining weight was also associated with an increased mortality risk. We examined changes in weight in relation to mortality in a prospective population-based cohort study of men and women, resident in Norfolk, UK. Participants were assessed at baseline (1993-1997) and at a second examination (1998-2000), as part of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) study, and followed up to 2015 for mortality. Participants with a self-reported history of cancer or cardiovascular disease, body mass index < 18.5 kg/m2 or missing data on adjustment variables, at either time-point were excluded, leaving 12,580 participants, aged 39-78 in 1993-1997, eligible for analyses. Cox proportional hazards models were used to determine Hazard Ratios (HRs) for all-cause (2603 deaths), cardiovascular (749 deaths), cancer (981 deaths), respiratory (226 deaths) and other causes of mortality (647 deaths) by categories of weight change. After multivariate adjustment, the HRs (95% CIs) for all-cause mortality for men and women who lost more than 5 kg were 1.85 (1.48-2.31) and 1.64 (1.31-2.05) respectively. Higher hazards were also found for specific causes of mortality and weight loss > 5 kg. Similar associations were observed after excluding deaths in the first 5 years of follow-up. Results for weight gain were inconclusive. We conclude that objectively measured weight loss, but not weight gain, was associated with subsequent higher mortality risk in this population-based study of middle-aged and elderly men and women. However, undiagnosed, pre-existing disease and the inability to account for weight cycling need to be remembered when interpreting these results. Unravelling the causal pathways underlying this association will require more detailed studies, including that of changes in body composition.