Efficacy of Trastuzumab in HER2-Positive Early Breast Cancer in Thai Patients: A Single Institution Experience
Pimchanok Patanayindee MD1, Kamonwan Soonklang MSc2, Teerapat Ungtrakul MD, MSc1,3
Affiliation : 1 Chulabhorn Hospital, HRH Princess Chulabhorn College of Medical Sciences, Chulabhorn Royal Academy, Bangkok, Thailand 2 Data Management Unit, HRH Princess Chulabhorn College of Medical Science, Chulabhorn Royal Academy, Bangkok, Thailand 3 Faculty of Medicine and Public Health, HRH Princess Chulabhorn College of Medical Sciences, Chulabhorn Royal Academy, Bangkok, Thailand
Objective : To evaluate the efficacy of 1-year adjuvant trastuzumab in Thai patients with HER2-positive early breast cancer.
The primary objective was to determine disease-free survival [DFS] and overall survival [OS] during 1 and 2 years.
Materials and Methods : We retrospectively reviewed the medical records of patients with HER2-positive early breast
cancer who received standard adjuvant chemotherapy with trastuzumab at Chulabhorn Hospital between January 2009 and
September 2014.
Results : Data of 39 women were available for analysis. Median age was 55 (48 to 60) years. Twenty-seven patients (69.1%)
had node-positive disease with median tumor size of 3.0 (0.7 to 12) cm 20 patients also had estrogen receptor-positive
disease. Anthracycline-based chemotherapy and taxane were given to 34 and 13 patients, respectively. During median
follow-up of 2 years, two patients with recurrence of breast cancer were observed. DFS rate at 1 and 2 years was 97.4% and
93.8%, respectively, whereas OS rate at 2 years was 100%. Unfortunately, congestive heart failure was identified in two
patients, with complete recovery after stopping trastuzumab.
Conclusion : Addition of adjuvant trastuzumab in HER2-positive early breast cancer yields a substantial benefit in DFS and
OS among the Thai population.
Keywords : HER2-positive early breast cancer, Trastuzumab, Adjuvant therapy, Overall survival
