Use of chemotherapy for early breast cancer in Germany, 2008-2017: A nationwide time-trend analysis
Riedel F.1, Hoffmann A.-S.1, Moderow M.2, Heublein S.1, Deutsch T.1, Golatta M.1, Wallwiener M.1, Schneeweiss A.1,3, Heil J.1, Hennigs A.1
1Universitätsklinikum Heidelberg, Universitäts-Frauenklinik Heidelberg, Heidelberg, Deutschland, 2Westdeutsches Brustcentrum GmbH, Düsseldorf, Deutschland, 3Nationales Centrum für Tumorerkrankungen, Heidelberg, Deutschland

Aim: Two major developments have taken place in systemic treatment of early breast cancer (EBC) during the past decade. First, chemotherapy is now used more specifically, due to better risk stratification. Second, neoadjuvant chemotherapy (NACT) now enables in vivo sensitivity testing and less radical surgery as compared to primary surgery and adjuvant chemotherapy (ACT). The aim of this study is to illustrate trends of systemic treatment of EBC with data from a large patient cohort.
Material and methods: This study analyzed chemotherapy usage and time trends for patients with EBC treated at 104 German breast units between January 2008 and December 2017. The data were obtained through a quality-controlled benchmarking process.
Results: Altogether, 124,084 patients were included, of whom 46,279 (37.3%) received chemotherapy. For 44,765 of these cases, detailed information on systemic treatment and surgery were available. In that cohort, chemotherapy was administered as NACT in 14,783 patients (33.0%) and as ACT in 29,982 (67.0%) patients. Overall use of chemotherapy declined from 42.0% in 2008 to 32.0% in 2017. During that same time, the proportion of NACT increased from 20.0% to 57.7%, irrespective of tumor subtype. The pathological complete response (pCR) rate (defined as ypT0 ypN0) at surgery after NACT increased from 15.0% to 34.2%.
Conclusions: The results from this large, nationwide cohort from the clinical routine reflect the refined indications for chemotherapy in EBC and the preference in Germany to apply chemotherapy as NACT. The increase of the pCR rate suggests improvements in oncological outcome.