| 1. |
- Blom, Johannes, et al.
(författare)
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A 9-year follow-up study of participants and nonparticipants in sigmoidoscopy screening : importance of self-selection
- 2008
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 17:5, s. 1163-1168
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Self-selection may compromise cost-effectiveness of screening programs. We hypothesized that nonparticipants have generally higher morbidity and mortality than participants. METHODS: A Swedish population-based random sample of 1,986 subjects ages 59 to 61 years was invited to sigmoidoscopy screening and followed up for 9 years by means of multiple record linkages to health and population registers. Gender-adjusted cancer incidence rate ratio (IRR) and overall and disease group-specific and mortality rate ratio (MRR) with 95% confidence intervals (95% CI) were estimated for nonparticipants relative to participants. Cancer and mortality rates were also estimated relative to the age-matched, gender-matched, and calendar period-matched Swedish population using standardized incidence ratios and standardized mortality ratios. RESULTS: Thirty-nine percent participated. The incidence of colorectal cancer (IRR, 2.2; 95% CI, 0.8-5.9), other gastrointestinal cancer (IRR, 2.7; 95% CI, 0.6-12.8), lung cancer (IRR, 2.2; 95% CI, 0.8-5.9), and smoking-related cancer overall (IRR, 1.4; 95% CI, 0.7-2.5) tended to be increased among nonparticipants relative to participants. Standardized incidence ratios for most of the studied cancers tended to be >1.0 among nonparticipants and <1.0 among participants. Mortality from all causes (MRR, 2.4; 95% CI, 1.7-3.4), neoplastic diseases (MRR, 1.9; 95% CI, 1.1-3.5), gastrointestinal cancer (MRR, 4.7; 95% CI, 1.1-20.7), and circulatory diseases (MRR, 2.3; 95% CI, 1.2-4.2) was significantly higher among nonparticipants than among participants. Standardized mortality ratio for the studied outcomes tended to be increased among nonparticipants and was generally decreased among participants. CONCLUSION: Individuals who might benefit most from screening are overrepresented among nonparticipants. This self-selection may attenuate the cost-effectiveness of screening programs on a population level.
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| 2. |
- Blom, Johannes
(författare)
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Aspects of participation in sigmoidoscopy screening for colorectal cancer
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal cancer is an important health problem due to a high morbidity and mortality but it is curable at an early stage and is therefore ideal for screening. Population-based screening of the average risk population using fecal occult blood testing has been demonstrated to decrease mortality. We are waiting for the results of randomized controlled trials evaluating sigmoidoscopy as a screening method. A high participation rate is a prerequisite for a screening program to be effective. The aim of this thesis was to evaluate the feasibility of sigmoidoscopy screening in a Swedish population with regard to compliance, findings and experiences among participants, factors associated with non-participation and possible self-selection among people participating. We randomly selected two thousand men and women, aged 59-61, residing in the uptake areas of the University Hospitals of Uppsala and Lund, and invited them to a screening sigmoidoscopy. These individuals were randomized to being telephoned by a nurse to schedule an appointment or asked to call and make the appointment themselves. After the sigmoidoscopy, the participants were asked to describe their experiences in a questionnaire using VAS scales. Participants with a pathological finding were planned for a colonoscopy. To study background factors associated with non-participation, various registers were utilized to provide information on each individual’s gender, country of birth, marital status, education, income, hospital contacts, place of residence, distance to screening center, and cancer within the family. All invitees were followed-up for nine years by means of record linkages to the Cancer- and Cause of Death Register. Thirty-nine per cent (771/1986) participated. There was a statistically significant difference in participation between the centers (47% Uppsala, 30% Lund), but not between the methods of invitation. A total of 11% (88/771) underwent colonoscopy. Three subjects were found to have colorectal cancer and 46 (6%) had adenomas. Overall, the participants’ answers to questions regarding self-perceived anxiety or discomfort were skewed towards low values on the VAS scale. The experience of pain and other discomfort could be explained by long examination time and anxiety during the procedure. Male gender (OR=1.27, 95% CI 1.03-1.57, relative to female), unmarried or divorced (OR=1.69, 95% CI 1.23-2.30 and OR=1.49, 95% CI 1.14-1.95, respectively, relative to married) and having an income in the lowest tertile (OR=1.68, 95% CI 1.27-2.23, relative to highest tertile) was associated with non-participation. The incidence of specific cancer and mortality outcomes tended to be higher among non-participants (e.g. colorectal cancer incidence [IRR=2.2, 95% CI 0.8-5.9] and mortality from gastrointestinal cancer [MRR=4.7, 95% CI 1.1-20.7]), compared those who participated. Relative to the matching general population, there was an overall increased risk of the studied outcomes among nonparticipants and a decreased risk among participants. For example, there was a 40% decreased risk of mortality from cancer (SMR=0.6 [0.3 to 0.97]) and a 50% decreased risk of all-cause mortality (SMR=0.5 [0.3 to 0.7]) among the participants. Our results indicate that screening with sigmoidoscopy is feasible in colorectal cancer screening if, however, participation is not hindered by the sigmoidoscopy per se. Invitations must appeal to men, unmarried individuals and people with low socio-economic status. The higher incidences of specific cancers and mortality among non-participants may be related to selfselection. This self-selection could attenuate the cost-effectiveness of screening programs on a population level, but this effect could be counteracted by a high participation rate.
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| 3. |
- Blom, Johannes, et al.
(författare)
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Routine fecal occult blood screening and colorectal cancer mortality in Sweden
- 2024
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Ingår i: JAMA Network Open. - : American Medical Association (AMA). - 2574-3805. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Population-based colorectal cancer (CRC) screening programs are implemented worldwide, but there are difficulties evaluating their effectiveness. The magnitude of routine CRC screening effectiveness regarding cancer-specific mortality is unclear.Objective: To evaluate cancer-specific mortality associated with early vs late or no invitation for routine CRC screening using fecal occult blood testing.Design, Setting, and Participants: This prospective cohort study was performed in the region of Stockholm-Gotland, Sweden, between January 1, 2008, and December 31, 2021. All individuals of the target population of screening born from 1938 to 1954 were included. Data were analyzed from December 12, 2022, to June 25, 2023.Exposures: Individuals were invited early (2008-2012), late (2013-2015), or not at all to screening with biennial guaiac-based fecal occult blood test. The early invitation group was considered the exposure group and the late or no invitation group was considered the control group.Main Outcomes and Measures: The main outcome was cancer-specific mortality, defined as CRC registered in the Cancer Register with CRC as underlying cause of death in the Cause of Death Register. Excess mortality was calculated as all-cause deaths among the individuals with CRC subtracted from the expected number of deaths had they not had CRC. Poisson regression analysis based on deaths and person-years was used to estimated mortality rate ratio (RR) with 95% CIs, adjusted for follow-up years and attained age.Results: In total, 379 448 individuals (193 436 [51.0%] female) were invited for CRC screening, including 203 670 individuals in the exposure group and 175 778 in the control group. The mean screening participation rate was 63.3%, and there was a maximum of 14 years follow-up. There were 834 CRC deaths in 2 190 589 person-years in the exposure group, compared with 889 CRC deaths in 2 249 939 person-years in the control group. Individuals who underwent early CRC screening had reduced adjusted risk of CRC mortality (RR, 0.86; 95% CI, 0.78-0.95) and excess mortality (RR, 0.84; 95% CI, 0.75-0.93).Conclusions and Relevance: This prospective cohort study of routine screening with fecal occult blood testing found a 14% decrease in CRC mortality associated with screening. The true association of screening with reduced mortality is expected to be higher due to some coexistence of testing in the control group and CRC deaths diagnosed more than 2 years after screening.
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| 4. |
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| 5. |
- Blom, Johannes, et al.
(författare)
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Toward understanding non participation in sigmoidoscopy screening for colorectal cancer
- 2008
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 122:7, s. 1618-1623
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the reasons for nonparticipation in cancer screening may give clues about how to improve compliance. However, limited cooperation has hampered research on nonparticipant profiles. We took advantage of Sweden's comprehensive demographic and health care registers to investigate characteristics of all participants and nonparticipants in a pilot program for colorectal cancer screening with sigmoidoscopy. A population-based sample of 1986 Swedish residents 59-61 years old was invited. Registers provided information on each individual's gender, country of birth, marital status, education, income, hospital contacts, place of residence, distance to screening center and cancer within the family. Odds ratios (ORs) with 95% confidence intervals (CIs), modeled with multivariable logistic regression, estimated the independent associations between each background factor and the propensity for nonparticipation after control for the effects of other factors. All statistical tests were 2-sided. Being male (OR = 1.27, 95% CI = 1.03-1.57, relative to female), unmarried or divorced (OR = 1.69, 95% CI = 1.23-2.30 and OR = 1.49, 95% CI = 1.14-1.95, respectively, relative to married) and having an income in the lowest tertile (OR = 1.68, 95% CI = 1.27-2.23, relative to highest tertile) was associated with increased nonparticipation. Living in the countryside or in small communities and having a documented family history of colorectal cancer was associated with better participation. Distance to the screening center did not significantly affect participation, nor did recent hospital care consumption or immigrant status. To increase compliance, invitations must appeal to men, unmarried or divorced people and people with low socioeconomic status.
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| 6. |
- Forsberg, Anna, et al.
(författare)
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Once-only colonoscopy or two rounds of faecal immunochemical testing 2 years apart for colorectal cancer screening (SCREESCO): preliminary report of a randomised controlled trial
- 2022
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Ingår i: The Lancet Gastroenterology & Hepatology. - : ELSEVIER INC. - 2468-1253. ; 7:6, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- Background Screening for colorectal cancer is done with lower gastrointestinal endoscopy or stool-based tests. There is little evidence from randomised trials to show primary colonoscopy reduces mortality in colorectal cancer We aimed to investigate the effect of screening with once-only colonoscopy or two rounds of faecal immunochemical test screening on colorectal cancer mortality and incidence. Methods We did a randomised controlled trial in Sweden (SCREESCO). Residents in 18 of 21 regions who were age 60 years in the year of randomisation were identified from a population register maintained by the Swedish Tax Agency. A statistician with no further involvement in the trial used a randomised block method to assign individuals to once-only colonoscopy, two rounds of faecal immunochemical testing (OC-Sensor; 2 years apart), or a control group (no intervention; standard diagnostic pathways), in a ratio of 1:6 for colonoscopy versus control and 1:2 for faecal immunochemical testing versus control. Masking was not possible due to the nature of the trial. The primary endpoints of the trial are colorectal cancer mortality and colorectal cancer incidence. Here, we report preliminary participation rates, baseline findings, and adverse events from March, 2014, to December, 2020, in the two intervention groups after completion of recruitment and screening, up to the completion of the second faecal immunochemical testing round. Analyses were done in the intention-to-screen population, defined as all individuals who were randomly assigned to the respective study group. This study is registered with Clinical Trials.gov, NCT02078804. Findings Between March 1, 2014, and Dec 31, 2020, 278 280 people were induded in the study; 31 140 were assigned to the colonoscopy group, 60 300 to the faecal immunochemical test group, and 186 840 to the control group. 10 679 (35.1%) of 30 400 people who received an invitation for colonoscopy participated. 33 383 (55.5%) of 60 137 people who received a postal faecal immunochemical test participated. In the intention-to-screen analysis, colorectal cancer was detected in 49 (0.16%) of 31140 people in the colonoscopy group versus 121 (0. 20%) of 60 300 in the faecal immunochemical test group (relative risk [RR] 0.78, 95% CI 0.56-1.09). Advanced adenomas were detected in 637 (2.05%) people in the colonoscopy group and 968 (1.61%) in the faecal immunochemical test group (RR 1.27, 95% CI 1.15-1.41). Colonoscopy detected more right-sided advanced adenomas than faecal immunochemical testing. There were two perforations and 15 major bleeds in 16 555 colonoscopies. No intervention-related deaths occurred. Interpretation The diagnostic yield and the low number of adverse events indicate that the design from this trial, both for once-only colonoscopy and faecal immunochemical test screening, could be transferred to a population-based screening service if a benefit in disease-specific mortality is subsequently shown. Copyright (C) 2022 Elsevier Ltd. All rights reserved.
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| 8. |
- Sjöström, Olle, 1973-
(författare)
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Risk and survival for colorectal cancer in northern Sweden : sociodemographic factors and surveillance programs
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundColorectal cancer (CRC) – i.e., cancer in the colon or rectum – is one of the most common cancers both globally and in Sweden. The risk for CRC is mainly related to age, heredity, and life-style risk factors. Previous studies have also demonstrated that individuals with lower socioeconomic status (SES), living alone, or far from care facilities may have a higher risk for CRC or a worse outcome. In contrast to life-style or sociodemographic-associated risks, an inherited risk for CRC is difficult to modify. However, colonoscopic surveillance programs can be help prevent CRC in families with a known hereditary risk.The Northern Health Care Region (northern Sweden) is the most sparsely populated region in Sweden, and travel distances to care can be long. The population in Northern Sweden is on average older and has lower SES compared with the rest of the country. The impact of these sociodemographic differences on CRC in northern Sweden is not well known. AimThis thesis analyses CRC in a northern Sweden setting with regards to incidence, survival, and associated sociodemographic risk factors, including prevention for individuals with increased hereditary risk.MethodsPapers I and II, cohort studies from the Risk North database, link individual data from health care registers to other sociodemographic registers. In Paper I, the incidence, mortality, and survival for all CRC cases in northern Sweden were compared with the rest of Sweden for the period 2007-2013. Uni- and multivariable Cox regression analysis were used to assess the impact of sociodemographic factors and tumour stage on survival by calculating hazard ratios (HR). In Paper II, we analysed any association between travel time to care and CRC survival in northern Sweden during 2007-2013 using the same type of Cox regression analysis. Papers III and IV are based on a cohort of individuals with a family history of CRC, prospectively recorded from 1995 to 2012 in the colonoscopic surveillance register at the Cancer Prevention Clinic at Umeå University Hospital. In Paper III, we evaluated the cancer preventive effect of the performed colonoscopic surveillance. Observed cases of CRC were compared to a cohort estimate of cases without surveillance. Compliance with surveillance and colonoscopic quality was also analysed. In Paper IV, we examined the cost-effectiveness of the colonoscopic surveillance program in Paper III. A cost-utility analysis with a societal perspective was used and the stability of the results was tested in a sensitivity analysis. ResultsThe age-adjusted incidence in colon cancer was 12.7% lower in northern compared to southern Sweden or 35.9/100 000 vs. 41.1/100 000 person years (p < 0.01). For rectal cancer, the incidence was 10.5% lower in the north (17.6 vs. 19.7 p <0.01). In subgroup analysis, the largest difference in incidence between northern and southern Sweden was found among individuals > 79 years age (colon - 190 vs. 237 ≈ 19.6%, rectal 72.4 vs. 88.0 ≈ 17.7%). For all of Sweden, the incidence in colorectal cancer was higher in males, individuals with lower SES, or individuals living alone. In univariable analyses of survival (all-cause and cause-specific) for colon and rectal cancer patients in all of Sweden, patients with high SES or co-habiting had a significantly better outcome compared to patients with low SES or living alone. HR for death ranged from 0.60 to 0.85 in the better-favoured risk group. No differences in colon or rectal cancer survival between northern and southern Sweden were demonstrated in the univariable analysis. However, in multivariable survival analysis, all-cause survival for colon cancer patients was better in southern Sweden (HR 0.92; 95% CI 0.86 – 0.97). For cause-specific survival for colon cancer or in any analysis for rectal cancer, no differences between northern and southern Sweden were demonstrated. In analysis of travel time, no association between travel time and survival was found. In the evaluation of the colonoscopic surveillance programme, one case of CRC was observed, compared to 9.5-10.5 expected cases. Standardised Incidence Ratio (SIR) between observed and expected cases of CRC was 0.10 (CI 95% 0.0012–0.53) to 0.11 (CI 95% 0.0014–0.59. The compliance to the surveillance program was 90%. The adenoma detection rate was 14%, and 10% of the examinations were incomplete. In the cost-utility analysis, the net cost for surveillance was 233 038 €, while saving 64.8 Quality Adjusted Life Years (QALYs) compared to non-surveillance. The resulting Incremental Cost-Effectiveness Ratio (ICER) was 3596 €/QALY, ranging from -4620 €/QALY in the best-case scenario to 33 779 € /QALY in the worst-case scenario.ConclusionThe incidence of CRC was lower in northern Sweden and most evident in the elderly, raising questions on differences in life-style between northern and southern Sweden in the past. There were considerable sociodemographic disparities in CRC survival in Sweden, including a lower all-cause survival for colon cancer patients in the north. In this study, travel time to care in northern Sweden did not affect survival and the lower all-cause survival in northern Sweden cannot be fully explained. The colonoscopic surveillance of families in northern Sweden with inherited risk for CRC had a good cancer preventive effect, including a high cost-effectiveness. The reasons for the good effect may be high compliance, since the quality of the colonoscopies was moderate.
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| 9. |
- Smailhodzic, Dzenita, et al.
(författare)
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Zinc supplementation inhibits complement activation in age-related macular degeneration.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. AMD is a multifactorial disorder but complement-mediated inflammation at the level of the retina plays a pivotal role. Oral zinc supplementation can reduce the progression of AMD but the precise mechanism of this protective effect is as yet unclear. We investigated whether zinc supplementation directly affects the degree of complement activation in AMD and whether there is a relation between serum complement catabolism during zinc administration and the complement factor H (CFH) gene or the Age-Related Maculopathy susceptibility 2 (ARMS2) genotype. In this open-label clinical study, 72 randomly selected AMD patients in various stages of AMD received a daily supplement of 50 mg zinc sulphate and 1 mg cupric sulphate for three months. Serum complement catabolism-defined as the C3d/C3 ratio-was measured at baseline, throughout the three months of supplementation and after discontinuation of zinc administration. Additionally, downstream inhibition of complement catabolism was evaluated by measurement of anaphylatoxin C5a. Furthermore, we investigated the effect of zinc on complement activation in vitro. AMD patients with high levels of complement catabolism at baseline exhibited a steeper decline in serum complement activation (p<0.001) during the three month zinc supplementation period compared to patients with low complement levels. There was no significant association of change in complement catabolism and CFH and ARMS2 genotype. In vitro zinc sulphate directly inhibits complement catabolism in hemolytic assays and membrane attack complex (MAC) deposition on RPE cells. This study provides evidence that daily administration of 50 mg zinc sulphate can inhibit complement catabolism in AMD patients with increased complement activation. This could explain part of the mechanism by which zinc slows AMD progression.
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| 10. |
- Thoren, Lina A., et al.
(författare)
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UPF2 Is a Critical Regulator of Liver Development, Function and Regeneration
- 2010
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nonsense-mediated mRNA decay (NMD) is a post-transcriptional RNA surveillance process that facilitates the recognition and destruction of mRNAs bearing premature terminations codons (PTCs). Such PTC-containing (PTC+) mRNAs may arise from different processes, including erroneous processing and expression of pseudogenes, but also from more regulated events such as alternative splicing coupled NMD (AS-NMD). Thus, the NMD pathway serves both as a silencer of genomic noise and a regulator of gene expression. Given the early embryonic lethality in NMD deficient mice, uncovering the full regulatory potential of the NMD pathway in mammals will require the functional assessment of NMD in different tissues. Methodology/Principal Findings: Here we use mouse genetics to address the role of UPF2, a core NMD component, in the development, function and regeneration of the liver. We find that loss of NMD during fetal liver development is incompatible with postnatal life due to failure of terminal differentiation. Moreover, deletion of Upf2 in the adult liver results in hepatosteatosis and disruption of liver homeostasis. Finally, NMD was found to be absolutely required for liver regeneration. Conclusion/Significance: Collectively, our data demonstrate the critical role of the NMD pathway in liver development, function and regeneration and highlights the importance of NMD for mammalian biology.
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