Contributing and limiting factors to guideline-adherent therapy in senior and elderly breast cancer patients: a questionnaire-based cross-sectional study using clinical and cancer registry data in Germany.

Reasons for deviations from guideline recommendations in breast cancer patients differ by age. In decision-making concerning elderly patients, particular attention should be paid to those with pre-existing depressive disorders. Adequately addressing their needs and concerns could prevent inappropriate deviations from guideline recommendations.