Abstract
Background: Modern treatment of breast cancer depends mainly on the expression of biomarkers such as estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). However, a change of receptors was not uncommon during the disease progression. Here we aim to evaluate the impact on clinical outcome from the conversion of receptors in primary tumor and recurrent or metastatic lesions.
Materials and methods: We retrospectively reviewed a cohort of patients who received breast cancer treatment in our hospital during 2012 to 2019. The study populations were stratified according to consistency or discordance of tumor phenotypes. The clinical outcomes were compared between the two groups in post-recurrence survival and overall survival.
Results: A total of 100 patients were confirmed with recurrence or metastasis with available specimen from recurrent lesion. The rates of discordance were 18%, 16%, 10% for ER, PR, and HER2, respectively. Thirty-eight percent patients had subtyping changed, whereas the other 62% patients presented the same subtype during progression. A better PRS was found in concordantly PR positive group compared with those with PR loss in recurrent tumors (not reached vs. 27 months, p=0.0465). Moreover, the low-HER2 group presented a worse survival outcome (PRS 27 months vs. 40 months, p=0.40) compared to whose HER2 status changed from negative to positive, although without significant difference.
Conclusion: Discordant receptors between primary and recurrent tumors exist in some patients with recurrence or metastasis. The recurrent lesions should be biopsied whenever feasible to tailor the appropriate therapy.
Keywords
Breast neoplasm, erbB-2, Hormone Receptors, Discordance, Survival