Paradoxes of breast cancer incidence and mortality in two corners of Europe

BACKGROUND: Breast cancer incidence is rising globally, while mortality rates show a geographical heterogenous pattern. Early detection and treatment have been proven to have a profound impact on breast cancer prognosis. The aim of his study was to compare breast cancer incidence, mortality, and survival rates in two contrasting corners of Europe, Sweden and Crete, to better understand cancer determinants with focus on disease burden and sociocultural factors. METHODS: Breast cancer data from Sweden and Crete was derived from registries. Incidence and mortality were expressed as Age-Standardized Incidence Rates (ASIR), Age-Standardized Mortality Rates (ASMR). FINDINGS: Breast cancer incidence has for decades risen in Sweden and on Crete. In 2019, ASIR was 217.5 in Sweden and 58.9 on Crete, (p < 0.001). Mortality rates showed opposite trends. ASMR in Sweden was reduced from 25.5 to 16.8 (2005-2019) while on Crete, ASMR increased from 22.1 to 25.3. A successive rise in survival rate in Sweden with a 5-year survival rate of 92% since 2015, but a converse development on Crete with 85% 5-year survival rate the same year. INTERPRETATION: The incidence of breast cancer is slowly rising in both studied regions, but mortality increases on Crete in contrast to Sweden with sinking mortality rates. The interpretation of these findings is that differences in health care systems and health policies including differences in early detection like screening programs and early treatment, as well as sociocultural factors in the two countries might play an important role on the differences found in breast cancer burden.