Trastuzumab emtansine prolongs survival in metastatic breast cancer
10 Apr 2021
Treatment with trastuzumab emtansine extends progression-free and overall survival with no serious safety concerns in patients with metastatic HER-2 positive breast cancer, reports a study. Eastern Cooperative Oncology Group-Performance Status (ECOG-PS), thrombocytopaenia, and cancer antigen 15-3 are all associated with survival.
This single-centre, retrospective, observational study analysed clinical data from 78 patients treated with trastuzumab emtansine for metastatic breast cancer from May 2016 through May 2019 at Kartal Dr Lutfi Kirdar Education and Research Hospital in Istanbul, Turkey.
The investigators analysed the following factors in relation to survival: cancer antigen 15-3 sensitivity, ECOG-PS, presence or absence of visceral metastases, presence of absence of cranial metastases, and treatment-related thrombocytopaenia.
Median progression-free and overall survival among patients 7.8 and 21.1 months, respectively. Of the 78 patients, 20 had an objective tumour response.
Trastuzumab emtansine was tolerable with a manageable safety profile, which was consistent with previous studies. The most common adverse events were anaemia, thrombocytopaenia, fatigue, and increased levels of alkaline phosphatase.
Patients with ECOG-PS=2 showed worse progression-free and overall survival than those with ECOG-PS <2. Those with cancer antigen 15-3–sensitive breast cancer also had worse progression-free and overall survival.
Furthermore, treatment-related thrombocytopaenia was a significant prognostic factor for survival. Patients with this condition had 12 months progression-free survival, while those without had only 4.1 months progression-free survival. Likewise, overall survival was much longer in patients with vs without thrombocytopaenia (29.5 vs 11.8 months).
“Ado-trastuzumab emtansine is an antibody-drug conjugate that combines the cytotoxic activity of emtansine with human epidermal growth factor receptor 2-targeted antitumour features of trastuzumab,” the investigators said.