Trends in female breast cancer incidence, mortality, and survival in Austria, with focus on age, stage, and birth cohorts (1983-2017).

Breast cancer (BC) is the most commonly diagnosed malignant disease and the leading cause of cancer death in women in Austria. We investigated overall and subgroup-specific female breast cancer rates to provide a comprehensive analysis of trends over several decades. Incidence, mortality, and survival, as well as age-, stage-, and birth cohort-specific incidence were analysed using nationwide cancer registry data on 163,694 cases of female breast cancer in Austria (1983-2017). Annual percentage changes were estimated using joinpoint regression. BC incidence underwent linear increases until 1997 and reversed with statistically non-significant declines until 2017. After initial increases in BC-specific mortality, rates were stable from 1989 through 1995 and started declining thereafter, although statistically non-significantly after 2011. Overall BC-specific survivals, as well as survivals according to the calendar period of diagnosis, increased throughout the observation period. Incidence in younger women (aged 44 and lower) showed linear increases, whereas for women aged 45 and higher mostly stable or decreasing rates were observed. Localised BC incidence increased markedly and started declining only in 2012. Distant disease-BC incidence decreased through the whole observation period and incidence of regionalised BC started declining in 2000. Birth cohort-specific incidence peaked in women born between 1935 and 1949 (ages 45-74). In conclusion, the incidence of BC in younger women is increasing, while overall female BC incidence and mortality are stable with non-significant declines. Further, increases in the incidence of early-stage BC (localised) seem disproportionately high in comparison to more modest decreases in late-stage BC incidence (regionalised and distant disease).