Trastuzumab treatment of patients with early, HER2-positive breast cancer in 17 certified German breast cancer centers.

In certified BCCs in Germany, guideline concordant trastuzumab recommendation is increasing since 2006 (positive cohort effect). Recommendation of trastuzumab for HER2-positive BC patients in BCCs is significantly associated with patients' age and the recommendations for other additional therapy strategies, apart from surgery. The quality assurance data analyzed do not include potentially relevant confounders, such as socioeconomic status or comorbidities.