Trends in surgical treatment for breast cancer in Germany after the implementation of the mammography screening program.

In Germany, the nationwide population-based mammography screening program (MSP) was introduced in 2005 and is full-running since 2010. By 2014, incidence rates for invasive breast cancer were very similar to those of the pre-screening era. Therefore, the ongoing effect of the MSP on breast cancer surgery rates can now be investigated. We analyzed population-based breast-conserving (BCS) and mastectomy (MET) surgery rates (per 100,000) among women aged < 50, 50-69 (eligible for the MSP), and 70+ years among women with in situ and invasive breast cancer during 2005-2015. For invasive breast cancer, both BCS and MET rates slightly increased in the age group < 50 years (38.3 in 2005 vs 42.5 in 2015 and 15.7 vs 18.2, respectively). In contrast, MET rates considerably decreased among women aged 50-69 and 70+ years (92 vs 65.4 and 155.4 vs 122.1, respectively), while BCS rates increased in both age groups (210.6 vs 254.4 and 147.2 vs 187, respectively). For in situ breast cancer, MET rates slightly increased in all age groups. BCS rates slightly increased in women aged < 50, but nearly doubled for women aged 50-69 (26.9 vs 49.1) and markedly increased in the 70+ age group (11.5 vs 16.1). During and after the implementation of MSP, there was a strong shift towards BCS within the screening-eligible age group and for women aged 70+ . Women with invasive breast cancer in these age groups may profit from screening with a decline of MET rates in favor of BCS rates at the expense of higher surgery rates for in situ breast cancer.