Overview

To evaluate the efficacy and safety of T-DXd in the treatment of HER2-positive breast cancer with brain metastases after treatment with pyrotinib

Eligibility

Inclusion Criteria:

        (1) Women ≥18 years of age :(2) pathological diagnosis of HER2-positive breast cancer,
        defined as positive immunohistochemistry detection (+++) or FISH(Fluorescent In Situ
        Hybridization); (3) Imaging evidence of brain metastases; (4) Progression of brain
        metastases after prior treatment with pyrotinib, defined as progression of new or
        pre-existing brain metastases during treatment with pyrotinib; (5)ECOG score ≤3 points; (6)
        The efficacy of T-DXd should be evaluated at least once after treatment; (7) Bone marrow
        and organ functions are basically normal; (8) Complete medical records
        Exclusion Criteria:
          -  Has uncontrolled or significant cardiovascular disease
          -  Has history of (noninfectious) interstitial lung disease (ILD)/pneumonitis that
             required steroids, has current ILD/pneumonitis, or suspected ILD/ pneumonitis that
             cannot be ruled out by imaging at screening
          -  Has any medical history or condition that per protocol or in the opinion of the
             investigator is inappropriate for the study