| 1. |
- Carninci, P, et al.
(författare)
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The transcriptional landscape of the mammalian genome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1559-1563
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Tidskriftsartikel (refereegranskat)abstract
- This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5′ and 3′ boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.
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| 2. |
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| 3. |
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| 4. |
- Larsson, LG, et al.
(författare)
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The Swedish randomised mammography screening trials: analysis of their effect on the breast cancer related excess mortality
- 1996
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Ingår i: Journal of medical screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 3:3, s. 129-32
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Tidskriftsartikel (refereegranskat)abstract
- –To apply an indirect method for estimation of the breast cancer related excess mortality in the Swedish randomised mammography screening trials.Setting–Randomised trials on mammography screening have, in Sweden, been performed in the counties of Kopparberg (W) and Östergötland (E), the so called WE study, and in the three largest cities in Sweden, Stockholm (southern part), Gothenburg, and Malmö. An overview of the trials was presented in the Lancet in 1993 and included 156 911 women in the invited group and 125 866 in the control group.Methods–The excess mortality in the breast cancer subgroups was estimated by indirect standardisation using official national cause of death statistics according to Statistics Sweden as a reference. Results—The estimated reduction of the breast cancer related mortality was 24% for the whole group (40–74 years at randomisation). The corresponding figures for the age groups 40–49, 50–59, and 60–69 years were 6%, 28%, and 34% respectively.Conclusion–The results are very similar to those presented earlier based on the traditional comparison of the breast cancer mortality in the invited and in the control group. This analysis further strengthens previous reports on a beneficial effect of mammography screening, which is especially pronounced in the age group 50–69.
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| 5. |
- Duffy, S, et al.
(författare)
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Estimates of overdiagnosis from two trials of mammographic screening for breast cancer
- 2005
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 7:6, s. 258-265
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Tidskriftsartikel (refereegranskat)abstract
- Randomised controlled trials have shown that the policy of mammographic screening confers a substantial and significant reduction in breast cancer mortality. This has often been accompanied, however, by an increase in breast cancer incidence, particularly during the early years of a screening programme, which has led to concerns about overdiagnosis, that is to say, the diagnosis of disease that, if left undetected and therefore untreated, would not become symptomatic. We used incidence data from two randomised controlled trials of mammographic screening, the Swedish Two-county Trial and the Gothenburg Trial, to establish the timing and magnitude of any excess incidence of invasive disease and ductal carcinoma in situ (DCIS) in the study groups, to ascertain whether the excess incidence of DCIS reported early in a screening trial is balanced by a later deficit in invasive disease and provide explicit estimates of the rate of 'real' and non-progressive 'overdiagnosed' tumours from the study groups of the trials. We used a multistate model for overdiagnosis and used Markov Chain Monte Carlo methods to estimate the parameters. After taking into account the effect of lead time, we estimated that less than 5% of cases diagnosed at prevalence screen and less than 1 % of cases diagnosed at incidence screens are being overdiagnosed. Overall, we estimate overdiagnosis to be around 1 % of all cases diagnosed in screened populations. These estimates are, however, subject to considerable uncertainty. Our results suggest that overdiagnosis in mammography screening is a minor phenomenon, but further studies with very large numbers are required for more precise estimation. © 2005 BioMed Central Ltd.
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Nystrom, L, et al.
(författare)
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An overview of the Swedish randomised mammography trials: total mortality pattern and the representivity of the study cohorts
- 1996
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Ingår i: Journal of medical screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 3:2, s. 85-7
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Tidskriftsartikel (refereegranskat)abstract
- –To analyse the cause of death pattern in the cohorts of women included in the Swedish randomised mammography screening trials by comparing the groups of invited and control women both with each other and with the general population of Swedish women. Setting –Since 1977 four randomised trials of mammography screening have been performed in Sweden: Malmö, Kopparberg and ÖOstergötland (the two county trial), Stockholm, and Gothenburg. Design –Overview of four randomised mammography screening trials. Results –The total numbers of deaths in the invited and control groups respectively were 15 695 and 11 887 corresponding to a relative risk (RR) of 1.00. There were no significant differences between the invited and control groups for cause-specific mortality, except for breast cancer. When the total mortality in the invited and the control groups was compared with that for Swedish women in general the standardised mortality ratio was close to 100. Conclusions –The cause of death pattern in the invited group was, except for breast cancer, very similar to that in the control group, showing that the groups were comparable. Similarly, the total mortality including breast cancer mortality in the control group was almost identical to that in Swedish women in general. The same was true, with the exception of breast cancer, for the invited group. These observations confirm that the trial cohorts are representative of Swedish women and indicate that the quantitative results from these trials may safely be generalised to the Swedish population.
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| 11. |
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| 12. |
- Brem, Rachel F., et al.
(författare)
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Assessing Improvement in Detection of Breast Cancer with Three-dimensional Automated Breast US in Women with Dense Breast Tissue : The Somoinsight Study
- 2015
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 0033-8419 .- 1527-1315. ; 274:3, s. 663-673
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine improvement in breast cancer detection by using supplemental three-dimensional (3D) automated breast (AB) ultrasonography (US) with screening mammography versus screening mammography alone in asymptomatic women with dense breasts. Materials and Methods: Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study. The SomoInsight Study was an observational, multicenter study conducted between 2009 and 2011. A total of 15 318 women (mean age, 53.3 years +/- 10 [standard deviation]; range, 2594 years) presenting for screening mammography alone with heterogeneously (50%75%) or extremely (>75%) dense breasts were included, regardless of further risk characterization, and were followed up for 1 year. Participants underwent screening mammography alone followed by an AB US examination; results were interpreted sequentially. McNemar test was used to assess differences in cancer detection. Results: Breast cancer was diagnosed at screening in 112 women: 82 with screening mammography and an additional 30 with AB US. Addition of AB US to screening mammography yielded an additional 1.9 detected cancers per 1000 women screened (95% confidence interval [CI]: 1.2, 2.7; P < .001). Of cancers detected with screening mammography, 62.2% (51 of 82) were invasive versus 93.3% (28 of 30) of additional cancers detected with AB US (P = .001). Of the 82 cancers detected with either screening mammography alone or the combined read, 17 were detected with screening mammography alone. Of these, 64.7% (11 of 17) were ductal carcinoma in situ versus 6.7% (two of 30) of cancers detected with AB US alone. Sensitivity for the combined read increased by 26.7% (95% CI: 18.3%, 35.1%); the increase in the recall rate per 1000 women screened was 284.9 (95% CI: 278.0, 292.2; P < .001). Conclusion: Addition of AB US to screening mammography in a generalizable cohort of women with dense breasts increased the cancer detection yield of clinically important cancers, but it also increased the number of false-positive results. (C)RNSA, 2014.
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| 13. |
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| 14. |
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| 15. |
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| 16. |
- Duffy, SW, et al.
(författare)
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Correcting for non-compliance bias in case-control studies to evaluate cancer screening programmes
- 2002
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Ingår i: The Journal of the Royal Statistical Society, Series C. - 0035-9254 .- 1467-9876. ; 51, s. 235-243
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Tidskriftsartikel (refereegranskat)abstract
- In the evaluation of uncontrolled service screening programmes for cancer, the case-control design is sometimes used, in which people who die from the disease in question are compared with live controls with respect to screening histories, Such a design tends to yield estimates of relative mortality in voluntary participants compared with non-participants. This may bias results, since compliers and non-compliers may differ a priori in ways which are not related to screening but which nevertheless affect the risk of death from the disease. We present a simple method, employing external data from previously published randomized controlled trials of screening, of correction for this bias. We illustrate it by using data from a case-control study performed within the invited arm of the Malmo mammographic screening trial, a prospective study from the service screening programme in two counties in Sweden, and a matched case-control study of mammographic screening in Florence, Italy.
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| 17. |
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| 18. |
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| 19. |
- Duffy, SW, et al.
(författare)
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The relative contributions of screen-detected in situ and invasive breast carcinomas in reducing mortality from the disease
- 2003
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Ingår i: European Journal of Cancer. - 0959-8049 .- 1879-0852. ; 39:12, s. 1755-1760
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to quantify the benefits of detecting ductal carcinoma in situ (DCIS) and of downwards stage-shifting within invasive tumours in mammographic screening. Using data from the Swedish Two-County Trial of breast cancer screening, we examined the 20-year death rates from invasive tumours of stage II or worse, invasive tumours of stage I and DCIS. We then used these rates and their respective incidences in invited (active study population, ASP) and control (passive study population, PSP) arms of the trial, to estimate the numbers of deaths avoided by downward stage-shifting the larger stage II or worse tumours to stage I and the stage I cancers to DCIS. We also studied the association between the mortality reduction achieved and the proportion of DCIS cases detected in the randomised trials of breast cancer screening. In the Swedish Two County Trial, 141 breast cancer deaths were avoided in the ASP compared with the PSP at approximately 20 years of follow-up. Of these, 65% (91/141) were avoided as a result of stage-shifting from invasive stage II or worse to invasive stage I, and 5% (7/141) as a result of stage-shifting from invasive stage I to DCIS. If we assumed that 10% of stage II or worse tumours avoided were shifted not to stage I, but to DCIS, the estimated number of deaths prevented by shifting from invasive disease to in situ was 17, which is 12% of all deaths prevented. When the results of all the randomised trials of breast cancer screening were reviewed, there was no clear association between the percentage of DCIS cases diagnosed and the observed mortality reduction. We conclude that compared with downward stage-shifting of invasive tumours, detection of DCIS plays a small part in saving lives from breast cancer. Treatment decisions in DCIS, as in invasive carcinoma, should take full account of histopathological, clinical and radiological attributes of the tumour. ⌐ 2003 Elsevier Ltd. All rights reserved.
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| 20. |
- Duffy, S. W., et al.
(författare)
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Overdiagnosis and overtreatment of breast cancer: estimates of overdiagnosis from two trials of mammographic screening for breast cancer
- 2005
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Ingår i: Breast Cancer Res. - 1465-542X. ; 7:6, s. 258-65
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Tidskriftsartikel (refereegranskat)abstract
- Randomised controlled trials have shown that the policy of mammographic screening confers a substantial and significant reduction in breast cancer mortality. This has often been accompanied, however, by an increase in breast cancer incidence, particularly during the early years of a screening programme, which has led to concerns about overdiagnosis, that is to say, the diagnosis of disease that, if left undetected and therefore untreated, would not become symptomatic. We used incidence data from two randomised controlled trials of mammographic screening, the Swedish Two-county Trial and the Gothenburg Trial, to establish the timing and magnitude of any excess incidence of invasive disease and ductal carcinoma in situ (DCIS) in the study groups, to ascertain whether the excess incidence of DCIS reported early in a screening trial is balanced by a later deficit in invasive disease and provide explicit estimates of the rate of 'real' and non-progressive 'overdiagnosed' tumours from the study groups of the trials. We used a multistate model for overdiagnosis and used Markov Chain Monte Carlo methods to estimate the parameters. After taking into account the effect of lead time, we estimated that less than 5% of cases diagnosed at prevalence screen and less than 1% of cases diagnosed at incidence screens are being overdiagnosed. Overall, we estimate overdiagnosis to be around 1% of all cases diagnosed in screened populations. These estimates are, however, subject to considerable uncertainty. Our results suggest that overdiagnosis in mammography screening is a minor phenomenon, but further studies with very large numbers are required for more precise estimation.
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| 21. |
- Duffy, S.W., et al.
(författare)
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The Swedish two-county trial of mammographic screening : Cluster randomisation and end point evaluation
- 2003
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534 .- 1569-8041. ; 14:8, s. 1196-1198
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Swedish Two-County Trial has been criticised on the grounds of the cluster randomisation and alleged bias in classification of cause of death. Patients and methods: In the Two-County Trial, 77080 women were randomised to regular invitation to screening (active study population, ASP) and 55985 to no invitation (passive study population, PSP), in 45 geographical clusters. After ~7 years, the PSP was invited to screening and the trial closed. We analysed data using hierarchical statistical models to take account of cluster randomisation, and performed a conservative analysis assuming a systematic difference between ASP and PSP in baseline breast cancer mortality in one of the counties. We also analysed deaths from causes other than breast cancer and from all causes among breast cancer cases diagnosed in the ASP and PSP. Results: Taking account of the cluster randomisation there was a significant 30% reduction in breast cancer mortality in the ASP. Conservatively, assuming a systematic difference between ASP and PSP clusters in baseline breast cancer mortality, there was a significant 27% reduction in mortality in the ASP. Ignoring classification of cause of death, there was a significant 13% reduction in all-cause mortality in breast cancer cases in the ASP. Conclusions: Breast cancer mortality is a valid end point and mammographic screening does indeed reduce mortality from breast cancer. The criticisms of the Swedish Two-County Trial are unfounded.
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| 22. |
- Duffy, S.W., et al.
(författare)
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Tumor size and breast cancer detection : What might be the effect of a less sensitive screening tool than mammography?
- 2006
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Ingår i: The Breast Journal. - 1075-122X .- 1524-4741. ; 12:SUPPL. 1
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Tidskriftsartikel (refereegranskat)abstract
- In some limited-resource areas, a state-of-the-art mammography program is not affordable. In such circumstances, one might consider a less resource-intensive, but also less sensitive screening tool such as clinical breast examination (CBE). We used data from the Swedish Two-County Trial to estimate the shift in tumor size resulting from invitation to mammographic screening. By postulating a lesser benefit of a less sensitive screening tool (CBE), particularly in terms of detecting very small tumors, we predicted its likely effect on tumor size distribution. In addition, using the observed association between tumor size and nodal status, and between tumor size and fatality, we predicted the likely benefit in terms of reductions in node-positive disease and in breast cancer mortality. An invitation to mammographic screening was associated with a 27% reduction in the number of node-positive tumors and a 31% reduction in the number of breast cancer deaths. We estimate that in the trial population, screening with CBE alone would have led to an 11% reduction in node-positive tumors and an 11% reduction in breast cancer deaths (approximately 42 deaths prevented per 1000 cases). Assuming instead a tumor size distribution typical of a limited-resource setting (70% of tumors are 30 mm at presentation), we estimate that screening with CBE alone would lead to a 13% reduction in node-positive tumors and a 12% reduction in breast cancer deaths (approximately 72 deaths prevented per 1000 cases). Thus, although the relative benefit of CBE is only slightly greater in the limited-resource setting, the absolute reduction in deaths per case is about 70% higher. Our findings suggest that a less sensitive tool might be expected to confer a breast cancer mortality reduction about half of that observed with mammography. © 2006 The Fred Hutchinson Cancer Research Center.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
- Holmberg, Lars, et al.
(författare)
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Differences in endpoints between the Swedish W-E (two county) trial of mammographic screening and the Swedish overview : methodological consequences
- 2009
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Ingår i: Journal of Medical Screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 16:2, s. 73-80
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To characterize and quantify the differences in the number of cases and breast cancer deaths in the Swedish W-E Trial compared with the Swedish Overview Committee (OVC) summaries and to study methodological issues related to trials in secondary prevention. SETTING: The study population of the W-E Trial of mammography screening was included in the first (W and E county) and the second (E-county) OVC summary of all Swedish randomized mammography screening trials. The OVC and the W-E Trial used different criteria for case definition and causes of death determination. METHOD: A Review Committee compared the original data files from W and E county and the first and second OVC. The reason for a discrepancy was determined individually for all non-concordant cases or breast cancer deaths. RESULTS: Of the 2615 cases included by the W-E Trial or the OVC, there were 478 (18%) disagreements. Of the disagreements 82% were due to inclusion/exclusion criteria, and 18% to disagreement with respect to cause of death or vital status at ascertainment. For E-County, the OVC inclusion rules and register based determination of cause of death (second OVC) rather than individual case review (W-E Trial and 1st OVC) resulted in a reduction of the estimate of the effect of screening, but for W-County the difference between the original trial and the OVC was modest. CONCLUSIONS: The conclusion that invitation to mammography screening reduces breast cancer mortality remains robust. Disagreements were mainly due to study design issues, while disagreements about cause of death were a minority. When secondary research does not adhere to the protocols of the primary research projects, the consequences of such design differences should be investigated and reported. Register linkage of trials can add follow-up information. The precision of trials with modest size is enhanced by individual monitoring of case status and outcome status such as determination of cause of death.
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| 27. |
- Holmberg, Lars, et al.
(författare)
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Mammography casting-type calcification and risk of local recurrence in DCIS: analyses from a randomised study
- 2013
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Ingår i: British Journal of Cancer. - : Cancer Research UK. - 0007-0920 .- 1532-1827. ; 108:4, s. 812-819
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Tidskriftsartikel (refereegranskat)abstract
- Background: We studied the association between mammographic calcifications and local recurrence in the ipsilateral breast. less thanbrgreater than less thanbrgreater thanMethods: Case-cohort study within a randomised trial of radiotherapy in breast conservation for ductal cancer in situ of the breast (SweDCIS). We studied mammograms from cases with an ipsilateral breast event (IBE) and from a subcohort randomly sampled at baseline. Lesions were classified as a density without calcifications, architectural distortion, powdery, crushed stone-like or casting-type calcifications. less thanbrgreater than less thanbrgreater thanResults: Calcifications representing necrosis were found predominantly in younger women. Women with crushed stone or casting-type microcalcifications had higher histopathological grade and more extensive disease. The relative risk (RR) of a new IBE comparing those with casting-type calcifications to those without calcifications was 2.10 (95% confidence interval (Cl) 0.92-4.80). This risk was confined to in situ recurrences; the RR of an IBE associated with casting-type calcifications on the mammogram adjusted for age and disease extent was 16.4 (95% Cl 2.20-140). less thanbrgreater than less thanbrgreater thanConclusion: Mammographic appearance of ductal carcinoma in situ of the breast is prognostic for the risk of an in situ IBE and may also be an indicator of responsiveness to RT in younger women.
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| 28. |
- Katayama, S, et al.
(författare)
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Antisense transcription in the mammalian transcriptome
- 2005
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Ingår i: Science (New York, N.Y.). - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 309:5740, s. 1564-1566
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Tidskriftsartikel (refereegranskat)abstract
- Antisense transcription (transcription from the opposite strand to a protein-coding or sense strand) has been ascribed roles in gene regulation involving degradation of the corresponding sense transcripts (RNA interference), as well as gene silencing at the chromatin level. Global transcriptome analysis provides evidence that a large proportion of the genome can produce transcripts from both strands, and that antisense transcripts commonly link neighboring “genes” in complex loci into chains of linked transcriptional units. Expression profiling reveals frequent concordant regulation of sense/antisense pairs. We present experimental evidence that perturbation of an antisense RNA can alter the expression of sense messenger RNAs, suggesting that antisense transcription contributes to control of transcriptional outputs in mammals.
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| 29. |
- Liljegren, Göran, et al.
(författare)
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10-year Results After Sector Resection With or Without Postoperative Radiotherapy for Stage I Breast Cancer : a Randomized Trial
- 1999
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Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 17:8, s. 2326-2333
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To study the long-term effectiveness of postoperative radiotherapy after sector resection for breast cancer in a randomized trial in which mammography is a major pathway to diagnosis. PATIENTS AND METHODS: Three hundred eighty-one women with a unifocal breast cancer < or = 20 mm in diameter on the preoperative mammogram and without histopathologic signs of axillary metastases were treated by sector resection plus axillary dissection. Of these patients, 184 women were randomized to receive postoperative radiotherapy to the breast (XRT group), and 197 women received no further treatment (non-XRT group). RESULTS: The local recurrence rate was 8.5% (95% confidence interval [CI], 3.9% to 13.1%) in the XRT group and 24.0% (95% CI, 17.6% to 30.4%) in the non-XRT group (P =.0001). Survival free from regional and distant recurrence was 83. 3% in the XRT group (95% CI, 77.5% to 89.1%) and 80.0% in the non-XRT group (95% CI, 73.9% to 86.1%) (P =.23). Overall survival was 77.5% in the XRT group (95% CI, 70.9% to 84.1%) and 78% in the non-XRT group (95% CI, 71.7% to 84.3%) (P =.99). A subgroup analysis suggested that women older than 55 years of age without comedo or lobular carcinomas had a low risk of local recurrence of 6.1% (95% CI, 0.1% to 9.1%) in the XRT-group and 11.0% (4.0% to 18.0%) in the non-XRT group (P =.16). CONCLUSION: Sector resection plus radiotherapy resulted in an absolute reduction in local recurrence of 16% at 10 years compared with surgery alone. Women older than 55 years of age without comedo or lobular carcinomas may have a low risk of local recurrence. Postoperative radiotherapy was not shown to reduce distant recurrences or improve overall survival.
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| 34. |
- Tabar, L., et al.
(författare)
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All-cause mortality among breast cancer patients in a screening trial : Support for breast cancer mortality as an end point
- 2002
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Ingår i: Journal of Medical Screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 9:4, s. 159-162
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Tidskriftsartikel (refereegranskat)abstract
- Background: It has recently been suggested that all-cause mortality is a more appropriate end point than disease specific mortality in cancer screening trials, and that disease specific mortality is biased in favour of screening. This suggestion is based partly on supposed inconsistencies between all-cause mortality results and disease specific results in cancer screening trials, and alleged increases in deaths from causes other than breast cancer among breast cancer cases diagnosed among women invited to screening. Methods: We used data from the Swedish Two-County Trial of mammographic screening for breast cancer, in which 77 080 women were randomised to an invitation to screening and 55 985 to no invitation. We estimated relative risks (RRs) (invited v control) of death from breast cancer, death from other causes within the breast cancer cases, and death from all causes within the breast cancer cases. RRs were adjusted for age and took account of the longer follow up of breast cancer cases in the invited group due to lead time. Results: There was a significant 31% reduction in breast cancer mortality in the invited group (RR 0.69, 95% confidence interval (Cl) 0.58-0.80, p
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| 35. |
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| 36. |
- Tabar, L, et al.
(författare)
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Beyond randomized controlled trials - Organized mammographic screening substantially reduces breast carcinoma mortality
- 2001
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Ingår i: Cancer. - 0008-543X .- 1097-0142. ; 91:9, s. 1724-1731
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND, The efficacy of mammographic screening in the reduction of breast carcinoma mortality has been demonstrated in randomized controlled trials. However, the evaluation of organized screening outside of research settings (so-called "service screening") faces unique methodologic and conceptual challenges. The current study describes the evaluation of organized mammography screening in a clinical setting and demonstrates the benefit obtained from service screening in two Swedish counties. METHODS. In the group of subjects ages 20-69 years, there were 6807 women diagnosed with breast carcinoma over a 29-year period in 2 counties in Sweden and 1863 breast carcinoma deaths. All patients were classified from patient charts based on their screening status (i.e., whether they had been invited to undergo screening and whether they actually had undergone screening). The number of women who lived in the 2 counties during the 29-year study period was provided by the Central Bureau of Statistics. Breast carcinoma-specific mortality was compared across three time periods: 1) 1968-1977, when no screening was taking place because mammography had not been introduced, 2) 1978-1987, the approximate period of the Two-County randomized controlled trial of screening in women ages 40-74 years, and 3) 1988-1996, when all women in the 2 counties ages 40-69 years were invited to undergo screening (service screening). When comparing breast carcinoma mortality in screened women with that in women diagnosed before screening was introduced, a correction for self-selection bias was incorporated to prevent overestimation of the benefit of screening. RESULTS. The mortality from incident breast carcinoma diagnosed in women ages 40-69 years who actually were screened during the service screening period (1988-1996) declined significantly by 63% (relative risk [RR] = 0.37, 95% CI, 0.30-0.46) compared with breast carcinoma mortality during the time period when no screening was available (1968-1977). The mortality decline was 50% (RR = 0.50, 95% CI, 0.41-0.60) when breast carcinoma mortality among all women who were invited to undergo screening (nonattendees included) was compared with breast cancer mortality during the time period when no screening was available (1968-1977). The reduction in mortality observed during the service screening period, adjusted for selection bias, was 48% (RR = 0.52, 95% CI, 0.43-0.63). No significant change in breast carcinoma mortality was observed over the three time periods in women who did not undergo screening. This group included women ages 20-39 years because these individuals were never invited to undergo screening, and women ages 40-69 years who did not undergo screening (not invited during the randomized trial or invited during the second and third time periods but declined). CONCLUSIONS. Regular mammographic screening resulted in a 63% reduction in breast carcinoma death among women who actually underwent screening. The policy of invitation to organized screening with mammography appears to have reduced breast carcinoma mortality by 50% in these 2 counties. (C) 2001 American Cancer Society.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
- Tabar, L, et al.
(författare)
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Mammography service screening and mortality in breast cancer patients : 20-year follow-up before and after introduction of screening
- 2003
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 361:9367, s. 1405-1410
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Tidskriftsartikel (refereegranskat)abstract
- Background: The long term effect of mammographic service screening is not well established. We aimed to assess the long-term effect of mammographic screening on death from breast cancer, taking into account potential biases from self-selection, changes in breast cancer incidence, and classification of cause of death. Methods: We compared deaths from breast cancer diagnosed in the 20 years before screening was introduced (1958-77) with those from breast cancer diagnosed in the 20 years after the introduction of screening (1978-97) in two Swedish counties, in 210 000 women aged 20-69 years. We also compared deaths from all cancers and from all causes in patients diagnosed with breast cancer in the 20 years before and after screening was introduced. In the analysis, data were stratified into age-groups invited for screening (40-69 years) and not invited (20-39 years), and by whether or not the women had actually received screening. We also analysed mortality for the 40-49-year age-group separately. Findings: The unadjusted risk of death from breast cancer dropped significantly in the second screening period compared with the first in women aged 40-69 years (relative risk [RR] 0.77 [95% CI 0.7-0.85], p<0.0001). No such decline was seen in 20-39 year olds. After adjustment for age, self-selection bias, and changes in breast-cancer incidence in the 40-69 years age-group, breast-cancer mortality was reduced in women who were screened (0.56, 0.49-0.64 p<0.0001), in those who were not screened (0.84 [0.71-0.99], p=0.03), and in screened and unscreened women combined (0.59 [0.53-0.66], p<0.0001). After adjustment for age, self-selection bias, and changes in incidence in the 40-49-year age-group, deaths from breast cancer fell significantly in those who were screened (0.52 [0.4-0.67], p<0.0001), and in all women, screened and unscreened combined (0.55 [0.44-0.7] p<0.0001) but not in unscreened women (p=0.2). In both 40-69-year and 40-49-year age-groups, reductions in deaths from all cancers and from all-causes in women with breast cancer were consistent with these results. Interpretation Taking account of potential biases, changes in clinical practice and changes in the incidence of breast cancer, mammography screening is contributing to substantial reductions in breast cancer mortality in these two Swedish counties.
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| 42. |
- Tabar, L., et al.
(författare)
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Number needed to screen : Lives saved over 20 years of follow-up in mammographic screening
- 2004
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Ingår i: Journal of Medical Screening. - : SAGE Publications. - 0969-1413 .- 1475-5793. ; 11:3, s. 126-129
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To estimate the number needed to screen with mammography to save one life, based on a stated amount of screening activity and long-term follow-up for breast cancer death. Setting: A randomised controlled trial of mammographic screening for breast cancer, with 77,080 women invited to screening and 55,985 not invited. The invited group was offered screening for seven years. Follow-up continued for a total of just over 20 years. Methods: Number needed to screen for seven years to save one life over 20 years was calculated by dividing the number screened (not the number invited) by the total number of lives saved. Similarly, we calculated the number of mammographic examinations required to save one life. Results: We estimate that the number of women needed to screen for seven years to save one life over 20 years is 465 (95% CI 324-819). The number of mammographic examinations needed to save one life was 1499 (95% CI 1046-2642). Conclusions: The number needed to screen to save one life is smaller than has been reported in the past. Mammographic screening is effective in absolute terms as well as relative. Long-term follow-up allowed us to estimate the absolute benefit with greater accuracy.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
- Tabar, L, et al.
(författare)
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The Swedish two-county trial twenty years later - Updated mortality results and new insights from long-term follow-up
- 2000
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Ingår i: The Radiologic clinics of North America. - 0033-8389 .- 1557-8275. ; 38:4, s. 625-
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Tidskriftsartikel (refereegranskat)abstract
- This article updates the results 20 years later of the Swedish Two-County Trial of mammographic screening for breast cancer. The result remains a substantial and significant 32% reduction in breast cancer mortality in association with an invitation to be screened. It is shown that the effect of screening can be ascribed to a shift in the prognostic character of the tumors diagnosed, that in turn can be used as a measure of the quality of a screening program. The results on prognosis also identify a group of small but high-risk tumors, with fundamental implications for diagnosis and treatment.
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| 47. |
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| 48. |
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| 49. |
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| 50. |
- Warwick, J., et al.
(författare)
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Time-Dependent Effects on Survival in Breast Carcinoma : Results of 20 Years of Follow-Up from the Swedish Two-County Study
- 2004
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Ingår i: Cancer. - : Wiley. - 0008-543X .- 1097-0142. ; 100:7, s. 1331-1336
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Tumor size, lymph node status, and histologic grade are reported to be important predictors of survival in the first 5 years after the diagnosis of invasive breast carcinoma. However, to the authors' knowledge, the effect of these factors in the longer term (> 10 years after diagnosis) is not yet clear. METHODS. It is now > 20 years since the Swedish Two-County Trial of breast carcinoma screening with mammography was instigated and long-term follow-up is now available to December 1998. In the current study, the authors analyzed the effects of tumor size, lymph node status, and tumor grade on survival to death from breast carcinoma using Cox regression and frailty models that allow the baseline hazard and/or effect of a covariate to vary with time. RESULTS. The effects of tumor size, lymph node status, and tumor grade were shown to progressively diminish with time from diagnosis. The Cox regression model with time-varying coefficients and a dampening parameter then was fitted to allow for the attenuation of prognostic effects, tumor size, lymph node status, and tumor grade were all found to be highly significant (P < 0.001). CONCLUSIONS. The results of the current study suggest that long-term survival in women with invasive breast carcinoma could be modelled satisfactorily using either frailty models or Cox regression models with time-varying coefficients. The results also suggest that the value of tumor grade, lymph node status, and tumor size at the time of diagnosis have a lasting influence on subsequent survival, albeit attenuated in later years. The long-term effects of these prognostic factors may explain the fact that the impact of mass screening programs on breast carcinoma mortality rates is still apparent many years later. © 2004 American Cancer Society.
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