North Clin Istanb. 2025 Aug 26;12(4):461-467. doi: 10.14744/nci.2025.48902. eCollection 2025.
ABSTRACT
OBJECTIVE: Ado-trastuzumab emtansine (T-DM1) is a key treatment for HER2-positive metastatic breast cancer (HER2+ MBC), yet the influence of progression sites and therapy lines on outcomes remains unclear.To assess the relationship between progression sites and the line of T-DM1 therapy with survival outcomes in HER2+ MBC.
METHODS: We retrospectively analyzed 123 patients with HER2+ MBC treated with T-DM1. Data on metastatic progression sites (brain, liver, bone, lung, lymph nodes), line of T-DM1 therapy (2nd-line vs ≥3rd-line), and death status were examined. Due to limited survival time data, mortality was used as the primary outcome. Death rates were compared across subgroups using descriptive statistics.
RESULTS: Brain and lung progression were associated with the highest mortality rates (76.7% and 73.1%, respectively). Liver and bone progression also showed elevated death rates (70.0% and 64.3%). Notably, more patients who used T-DM1 as the second-line therapy had a higher mortality rate at 66.7% compared to those treated with it in the third line or after (45.1%).
CONCLUSION: Progression to brain and lung during T-DM1 treatment correlates with higher mortality. Early-line use of T-DM1 may be linked with worse outcomes, possibly due to more aggressive disease biology. The obtained data could inform the decision-making process when treating patients with HER2+ MBC and predict their prognosis.
PMID:41059432 | PMC:PMC12497911 | DOI:10.14744/nci.2025.48902
