Effects of guideline adherence in primary breast cancer--a 5-year multi-center cohort study of 3976 patients.

Background: The aim of that study was to analyze the impact of German-S3-breast cancer guideline adherence on clinical outcomes.

Methods: A retrospective study analyzed 3976 patients first diagnosed with primary breast cancer according to an S3-guideline-based model that classified patients retrospectively into groups receiving "guideline-adherent and "guideline non-adherent" therapy.

Results: There was a significant association between treatment adherence and prolonged recurrence free and overall survival (p = 0.