Receptor discordance after nipple-sparing mastectomy

Background Recent studies have shown that receptor status of breast cancer change between primary tumor and recurrence, which may influence treatment strategy and prognosis, but there are few reports on receptor discordance between primary tumors and local recurrence (LR) after nipple-sparing mastectomy (NSM). Patients and methods We collected 74 patients who had LR after NSM for newly diagnosed stages 0 to 3 breast cancer between 2008 and 2016 at 14 institutions. We classified into 4 subtypes based on hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2). We evaluated clinicopathological factors that correlate with receptor discordance and assessed the impact of receptor discordance on survival. Results Discordance rates in estrogen receptor (ER), progesterone receptor (PgR) and HER2 were 9.5, 10.8 and 5.4%, respectively. The most common change was from HR-/HER2+ to HR+/HER2+, and this pattern of receptor change occurred only in patients with nipple–areolar recurrence. Non-invasive tumor in LR, nipple–areolar recurrence (NAR), HR-/HER2+ primary tumor subtype, and the presence of chemotherapy for primary tumor were significantly associated with receptor discordance. With a median follow-up of 44.5 months (4-153 months), patients in the receptor-discordant group had no disease-free survival (DFS) event after LR resection (5-year DFS; 100% in the receptor-discordant group vs 85.1% in the receptor-concordant group; p = 0.2). Conclusion Our study demonstrated that the presence of chemotherapy for primary tumor, nipple-areolar recurrence, and its related factors (non-invasive tumor in LR, HR-/HER2+ primary tumor subtype) were associated with receptor discordance. However, further studies with longer follow-up periods and larger sample sizes are needed.