Objective To investigate the recurrent and metastatic characteristics, prognosis and efficacy of palliative trastuzumab treatment in advanced HER2-positive breast cancer patients with different hormone receptor status.

Methods We analyzed retrospectively the clinicopathologic data of 237 patients with advanced HER2-positive breast cancer. Patients were divided into HR+/HER2+ and HR-/HER2+ groups according to HR status. Clinicopathologic features, recurrent and metastatic characteristics, prognosis and palliative trastuzumab treatment efficacy were analyzed between two groups.

Results Compared with HR-/HER2+ group, HR+/HER2+ group were more presented to be premenopausal, and clinical stage were mainly Ⅰ-Ⅱ stage, with lower T stage and less axillary lymphocytic infiltration. Comparing the first and subsequent sites of recurrence, patients with HR+/HER2+ were more likely to have bone metastasis and less likely to have lung metastasis. The median metastases overall survivals (M-OS) was 34 (range: 5-102) months in the HR+/HER2+ group, and 29 (range: 3-70) months in HR-/HER2+ group, with significant difference. In patients with palliative trastuzumab plus chemotherapy treatment, 68.6% of ER < 50% and 46.2% of ER≥50% patients were partial remission, with statistically significant difference (P=0.037). Multivariate analysis showed that ER status was an independent predictor for the survival of advanced HR+/ HER2+ breast cancer patients; liver metastasis and palliative anti-HER2 targeted treatment were the independent predictors for the survival of advanced HR-/HER2+ breast cancer patients.

Conclusion Compared with HR-/HER2+ patients, HR+/HER2+ patients have more bone metastases and less lung metastases, with better prognosis; patients with higher proportion of ER-positive cells have a poorer response to trastuzumab.