| 1. |
- de Vogel, Stefan, et al.
(författare)
-
Biomarkers related to one-carbon metabolism as potential risk factors for distal colorectal adenomas
- 2011
-
Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 20:8, s. 1726-1735
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Efficient one-carbon metabolism, which requires adequate supply of methyl group donors and B-vitamins, may protect against colorectal carcinogenesis. However, plasma folate and vitamins B2 and B12 have inconsistently been associated with colorectal cancer risk, and there have been no previous studies relating plasma concentrations of methionine, choline, and betaine to this outcome.METHODS: This study comprised 10,601 individuals, 50 to 64 years of age, participating in the Norwegian Colorectal Cancer Prevention (NORCCAP) screening study. Using logistic regression analyses, we crosssectionally investigated associations between distal colorectal adenoma occurrence-potential precursor lesions of colorectal carcinomas-and plasma concentrations of methyl group donors and B-vitamins, and polymorphisms of genes related to one-carbon metabolism.RESULTS: Screening revealed 1,809 subjects (17.1%) with at least one adenoma. The occurrence of high-risk adenomas (observed in 421 subjects) was inversely associated with plasma concentrations of methionine (highest versus lowest quartile: odds ratio (OR) = 0.61; 95% confidence interval (CI) = 0.45-0.83), betaine: OR = 0.74; 95% CI = 0.54-1.02, the vitamin B2 form flavin-mononucleotide (FMN): OR = 0.65; 95% CI = 0.49-0.88, and the vitamin B6 form pyridoxal 5'-phosphate (PLP): OR = 0.69; 95% CI = 0.51-0.95, but not with folate, choline, vitamin B12 concentrations, or with the studied polymorphisms. High methionine concentration in combination with high vitamin B2 or B6 concentrations was associated with lower occurrence of high-risk adenomas compared with these factors individually.CONCLUSIONS: High plasma concentrations of methionine and betaine, and vitamins B2 and B6 may reduce risk of developing colorectal adenomas.IMPACT: In addition to B-vitamins, methyl group donors such as methionine and betaine may play a role in colorectal carcinogenesis.
|
|
| 2. |
- Hoff, Geir, et al.
(författare)
-
Risk of colorectal cancer seven years after flexible sigmoidoscopy screening : randomised controlled trial
- 2009
-
Ingår i: BMJ. British Medical Journal. - : BMJ. - 0959-8146 .- 0959-535X. ; 338, s. b1846-
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the risk of colorectal cancer after screening with flexible sigmoidoscopy. DESIGN: Randomised controlled trial. SETTING: Population based screening in two areas in Norway-city of Oslo and Telemark county (urban and mixed urban and rural populations). PARTICIPANTS: 55 736 men and women aged 55-64 years. INTERVENTION: Once only flexible sigmoidoscopy screening with or without a single round of faecal occult blood testing (n=13 823) compared with no screening (n=41 913). MAIN OUTCOME MEASURES: Planned end points were cumulative incidence and mortality of colorectal cancer after 5, 10, and 15 years. This first report from the study presents cumulative incidence after 7 years of follow-up and hazard ratio for mortality after 6 years. RESULTS: No difference was found in the 7 year cumulative incidence of colorectal cancer between the screening and control groups (134.5 v 131.9 cases per 100 000 person years). In intention to screen analysis, a trend towards reduced colorectal cancer mortality was found (hazard ratio 0.73, 95% confidence interval 0.47 to 1.13, P=0.16). For attenders compared with controls, a statistically significant reduction in mortality was apparent for both total colorectal cancer (hazard ratio 0.41, 0.21 to 0.82, P=0.011) and rectosigmoidal cancer (0.24, 0.08 to 0.76, P=0.016). CONCLUSIONS: A reduction in incidence of colorectal cancer with flexible sigmoidoscopy screening could not be shown after 7 years' follow-up. Mortality from colorectal cancer was not significantly reduced in the screening group but seemed to be lower for attenders, with a reduction of 59% for any location of colorectal cancer and 76% for rectosigmoidal cancer in per protocol analysis, an analysis prone to selection bias. TRIAL REGISTRATION: Clinical trials NCT00119912.
|
|
| 3. |
- Holme, Oyvind, et al.
(författare)
-
Effect of Flexible Sigmoidoscopy Screening on Colorectal Cancer Incidence and Mortality A Randomized Clinical Trial
- 2014
-
Ingår i: Journal of the American Medical Association (JAMA). - : American Medical Association. - 0098-7484 .- 1538-3598. ; 312:6, s. 606-615
-
Tidskriftsartikel (refereegranskat)abstract
- IMPORTANCEColorectal cancer is a major health burden. Screening is recommended in many countries. OBJECTIVE To estimate the effectiveness of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality in a population-based trial. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial of 100 210 individuals aged 50 to 64 years, identified from the population of Oslo city and Telemark County, Norway. Screening was performed in 1999-2000 (55-64-year age group) and in 2001 (50-54-year age group), with follow-up ending December 31, 2011. Of those selected, 1415 were excluded due to prior colorectal cancer, emigration, or death, and 3 could not be traced in the population registry.INTERVENTIONSParticipants randomized to the screening group were invited to undergo screening. Within the screening group, participants were randomized 1: 1 to receive once-only flexible sigmoidoscopy or combination of once-only flexible sigmoidoscopy and fecal occult blood testing (FOBT). Participants with positive screening test results (cancer, adenoma, polyp >= 10 mm, or positive FOBT) were offered colonoscopy. The control group received no intervention.MAIN OUTCOMES AND MEASURESColorectal cancer incidence and mortality.RESULTSA total of 98 792 participants were included in the intention-to-screen analyses, of whom 78 220 comprised the control group and 20 572 comprised the screening group (10 283 randomized to receive a flexible sigmoidoscopy and 10 289 to receive flexible sigmoidoscopy and FOBT). Adherence with screening was 63%. After a median of 10.9 years, 71 participants died of colorectal cancer in the screening group vs 330 in the control group (31.4 vs 43.1 deaths per 100 000 person-years; absolute rate difference, 11.7 [95% CI, 3.0-20.4]; hazard ratio [HR], 0.73 [95% CI, 0.56-0.94]). Colorectal cancer was diagnosed in 253 participants in the screening group vs 1086 in the control group (112.6 vs 141.0 cases per 100 000 person-years; absolute rate difference, 28.4 [95% CI, 12.1-44.7]; HR, 0.80 [95% CI, 0.70-0.92]). Colorectal cancer incidence was reduced in both the 50-to 54-year age group (HR, 0.68; 95% CI, 0.49-0.94) and the 55-to 64-year age group (HR, 0.83; 95% CI, 0.71-0.96). There was no difference between the flexible sigmoidoscopy only vs the flexible sigmoidoscopy and FOBT screening groups.CONCLUSIONS AND RELEVANCEIn Norway, once-only flexible sigmoidoscopy screening or flexible sigmoidoscopy and FOBT reduced colorectal cancer incidence and mortality on a population level compared with no screening. Screening was effective both in the 50-to 54-year and the 55-to 64-year age groups.
|
|
| 4. |
- Holme, Oyvind, et al.
(författare)
-
Long-Term Effectiveness of Sigmoidoscopy Screening on Colorectal Cancer Incidence and Mortality in Women and Men A Randomized Trial
- 2018
-
Ingår i: Annals of Internal Medicine. - : American College of Physicians. - 0003-4819 .- 1539-3704. ; 168:11, s. 775-782
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The long-term effects of sigmoidoscopy screening on colorectal cancer (CRC) incidence and mortality in women and men are unclear.Objective: To determine the effectiveness of flexible sigmoidoscopy screening after 15 years of follow-up in women and men.Design: Randomized controlled trial. (ClinicalTrials.gov: NCT00119912)Setting: Oslo and Telemark County, Norway. Participants: Adults aged 50 to 64 years at baseline without prior CRC.Intervention: Screening (between 1999 and 2001) with flexible sigmoidoscopy with and without additional fecal blood testing versus no screening. Participants with positive screening results were offered colonoscopy.Measurements: Age-adjusted CRC incidence and mortality stratified by sex.Results: Of 98 678 persons, 20 552 were randomly assigned to screening and 78 126 to no screening. Adherence rates were 64.7% in women and 61.4% in men. Median follow-up was 14.8 years. The absolute risks for CRC in women were 1.86% in the screening group and 2.05% in the control group (risk difference, -0.19 percentage point [95% CI, -0.49 to 0.11 percentage point]; HR, 0.92 [CI, 0.79 to 1.07]). In men, the corresponding risks were 1.72% and 2.50%, respectively (risk difference, -0.78 percentage point [CI, -1.08 to -0.48 percentage points]; hazard ratio [HR], 0.66 [CI, 0.57 to 0.78]) (P for heterogeneity = 0.004). The absolute risks for death from CRC in women were 0.60% in the screening group and 0.59% in the control group (risk difference, 0.01 percentage point [CI, -0.16 to 0.18 percentage point]; HR, 1.01 [CI, 0.77 to 1.33]). The corresponding risks for death from CRC in men were 0.49% and 0.81%, respectively (risk difference, -0.33 percentage point [CI, -0.49 to -0.16 percentage point]; HR, 0.63 [CI, 0.47 to 0.83]) (P for heterogeneity = 0.014).Limitation: Follow-up through national registries.Conclusion: Offering sigmoidoscopy screening in Norway reduced CRC incidence and mortality in men but had little or no effect in women.
|
|
