Table 2.

Enrichment of drug-resistant HER2 mutations (K753E and L755S) in metastatic lesions

CohortPatient codeHER2 mutation in metastatic tumorPrimary tumorERPRHER2HER2-targeted therapy
MetastaticCT1980K753EWT--+Trastuzumab for one year
CT2685L755SWT+++Trastuzumab for one year
CT3478L755SWT--+Trastuzumab for one year
CT3799K753EWT+++Trastuzumab for one year
CT4167L755SWT+-+Trastuzumab for one year