Effect of Screening Mammography on Breast-Cancer Mortality in Norway (original) (raw)
Cancer incidence, mortality, survival and prevalence in Norway
Because we have an aging population, the number of cancer cases increases every year. A total of 32 827 new cancer cases were diagnosed and reported in 2016. The changes are small compared with the previous year. In addition, we know that for most cancers there are some fluctuations in the rates from one year to another. Thus, to understand changes in the trends we need to compare the rates, not only from one year to another, but from the latest five-year period (2012)(2013)(2014)(2015)(2016) to the previous one (2007)(2008)(2009)(2010)(2011). This comparison shows a particularly large increase for melanoma of the skin, with more than a 20% increase since the previous five-year period among both men and women. Thyroid cancer is another cancer where we see a remarkable increase in incidence over time. Compared to the previous five-year period, there is a 30% rise in women, and more than 40% in men. This increase may be mostly due to increased use of ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) for other indications, and better cytological and/or histological diagnostics. We hope there is no opportunistic screening ongoing.
Acta Oncologica, 2006
The aim of the present study was to relate the time trends in breast cancer incidence and mortality to the introduction of mammography screening in the Nordic capitals. Helsinki offered screening to women aged 50 Á59 starting in 1986. The other three capitals offered screening to women aged 50 Á69 starting in 1989 in Stockholm, 1991 in Copenhagen, and 1996 in Oslo. Prevalence peaks in breast cancer incidence depended on the age groups covered by the screening, the length of the implementation of screening, and the extent of background opportunistic screening. No mortality reduction following the introduction of screening was visible after seven to 12 years of screening in any of the three capitals where significant effects of the screening on the breast cancer mortality had already been demonstrated by using other analytical methods for the evaluation. No visible effect on mortality reduction was expected in Oslo due to too short an observation period. The study showed that the population-based breast cancer mortality trend is too crude a measure to detect the effect of screening on breast cancer mortality during the first years after the start of a programme.
Using the European guidelines to evaluate the Norwegian Breast Cancer Screening Program
European Journal of Epidemiology, 2007
This is an evaluation of selected process indicators achieved during the first 10 years of performance of the Norwegian Breast Cancer Screening Program (NBCSP). The indicators are compared with the recommended levels given in the European Guidelines. The program invites all female residents aged 50-69 years old to two-view mammography biennially. The attendance rate was 76.2%. The recall rates due to positive mammography were 4.6% and 2.6%, and the detection rates were 6.4 and 4.9 per 1,000 screens, in prevalent and subsequent screens, respectively. Mean tumor size was 14.7 mm for screening detected and 21.2 mm for interval cancers. Axillary lymph node metastases were present in 25.4% and 43.8%, respectively. Detection mode (screening detected or interval cancer) was shown to be an independent predictor for axillary lymph node metastases and high-grade (Grade 3) tumors. The NBCSP meets the recommendations given in the European Guidelines for most of the process indicators evaluated in this study. Based on the results, we anticipate a future mortality reduction from breast cancer in women invited to the NBCSP.
Nordic Cancer Registries - an overview of their procedures and data comparability
Acta oncologica (Stockholm, Sweden), 2017
The Nordic Cancer Registries are among the oldest population-based registries in the world, with more than 60 years of complete coverage of what is now a combined population of 26 million. However, despite being the source of a substantial number of studies, there is no published paper comparing the different registries. Therefore, we did a systematic review to identify similarities and dissimilarities of the Nordic Cancer Registries, which could possibly explain some of the differences in cancer incidence rates across these countries. We describe and compare here the core characteristics of each of the Nordic Cancer Registries: (i) data sources; (ii) registered disease entities and deviations from IARC multiple cancer coding rules; (iii) variables and related coding systems. Major changes over time are described and discussed. All Nordic Cancer Registries represent a high quality standard in terms of completeness and accuracy of the registered data. Even though the information in t...
Breast cancer survival in England, Norway and Sweden: a population-based comparison
International Journal of Cancer, 2010
Several international studies have found that survival from breast cancer is lower in the United Kingdom than in some other European countries. We have compared breast cancer survival between the national populations of England, Norway and Sweden, with a view to identifying subsets of patients with particularly good or adverse survival outcomes. We extracted cases of breast cancer in women diagnosed 1996-2004 from the national cancer registries of the 3 countries. The study comprised 303,657 English cases, 24,919 Norwegian cases and 57,512 cases from Sweden. Follow-up was in 2001Follow-up was in -2004 The main outcome measures were 5-year cumulative relative survival and excess death rates, stratified by age and period of follow-up. In comparison with Norway and Sweden, the excess mortality in England was particularly pronounced in the first month and in the first year after diagnosis, and generally more marked in the oldest age groups. Compared with Norwegian patients, 81% of the excess deaths in the English patients occurred in the first 2 years after diagnosis. Our findings emphasise the importance of awareness of symptoms and early detection as the main strategy to improve breast cancer survival in the United Kingdom.