Abstract 185P
Background
The prognosis of patients with T1b breast tumours that are node-negative is not known for sure according to human epidermal growth factor receptor 2 (HER2) status. The group of patients was not studied in the available randomized trials. The object of this study was to evaluate survival in patients diagnosed with T1b, lymph node-negative breast cancer based on HER2 status.
Methods
We analysed data from 3,110 patients with T1bN0M0 breast cancer who were part of the Korean Breast Cancer Society Registry database between 2000 and 2009. The overall survival (OS) and breast cancer-specific survival (BCSS) were compared to HER2 status.
Results
494 patients had HER2-positive breast cancer (15.9%). At a mean follow-up of 98 months, 108 deaths and 86 breast cancer-specific deaths were recorded for all patients. There was no significant difference in OS between HER2-negative and positive groups (P=0.103). The same results were observed for BCSS. However, in the oestrogen receptor (ER)-positive subgroup, HER2-negative patients had a better prognosis for BCSS (P=0.025). Multivariate analysis also indicated a significant difference in BCSS in the ER-positive subgroup (HR; 95% 2.21 CI 1.12-4.37, P=0.023).
Conclusions
This study analysed a large cohort of patients and the results suggest a significant difference in BCSS only in the ER-positive subgroup according to HER2 status. Although patients with T1b tumours have an excellent prognosis, HER2 and ER status may indicate that patients with small, node-negative breast cancer should be considered for treatment with trastuzumab.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.