Trends in Breast Cancer Mortality Between 2001 and 2017: An Observational Study in the European Union and the United Kingdom.

PURPOSE:Breast cancer is the most common cancer in women worldwide, representing 25.4% of the newly diagnosed cases in 2018. The past two decades have seen advancements in screening technologies, guidelines, and newer modalities of treatment. Our study reports and compares trends in breast cancer mortality in the European Union and the United Kingdom. MATERIALS AND METHODS:We used the WHO Mortality Database. We extracted breast cancer mortality data from 2001 to 2017 on the basis of the International Classification of Diseases, 10th revision system. Crude mortality rates were dichotomized by sex and reported by year. We computed age-standardized death rates (ASDRs) per 100,000 population using the world standard population. Breast cancer mortality trends were compared using joinpoint regression analysis. RESULTS:We analyzed data from 24 EU countries, including the United Kingdom. For women, breast cancer mortality was observed to be downtrending in all countries except Croatia, France, and Poland. For the most recent female data, the highest ASDR for breast cancer was identified in Croatia (19.29 per 100,000), and the lowest ASDR was noted in Spain (12.8 per 100,000). Denmark had the highest change in ASDR and the highest estimated annual percentage change of -3.2%. For men, breast cancer mortality decreased in 18 countries, with the largest relative reduction observed in Denmark with an estimated annual percentage change of -27.5%. For the most recent male data, the highest ASDR for breast cancer was identified in Latvia (0.54 per 100,000). CONCLUSION:Breast cancer mortality rates have down trended in most EU countries between 2001 and 2017 for both men and women. Given the observational nature of this study, causality to the observed trends cannot be reliably ascribed. However, possible contributing factors should be considered and subject to further study.