Population-based hormone receptor-specific incidence trends of breast cancer in Germany.

OBJECTIVES: Several countries reported a drop in prescription of hormone replacement therapy (HRT) in the 2000s, followed by decreases in breast cancer incidence among postmenopausal women aged 50-69 years. The aim of this study was to provide hormone receptor specific incidence rates of breast cancer in Germany. METHODS: Breast cancer data were extracted from the cancer registries of the Federal States of Brandenburg and Saarland and the area of Munich for the period from 1998 to 2007. We obtained nationwide data on HRT prescription in 1998-2007 from health insurances. Multiple imputation was used on missing values for the receptor status. Age-standardized (European standard population) and age-specific rates were calculated. RESULTS: The age-standardized incidence rates in breast cancer were virtually constant over the entire period in all regions. In particular, no substantial changes over time occurred within the age- and receptor-specific analyses. In the same period we observed a drop in HRT use, starting in 1999 and leveling off in 2004. The incidence trends of carcinoma in situ of the female breast increased during the study period. CONCLUSIONS: In our data, we did not observe an association between the decline in HRT prescription and breast cancer incidence among women aged from 50 to 69 years. The lack of temporal changes in breast cancer incidence may be explained by introduction of opportunistic and organized mammography screening and low absolute levels of HRT prescription in Germany.