Expression of high affinity folate receptor in breast cancer brain metastasis

// Jose Pablo Leone 1 , Rohit Bhargava 2 , Brian K. Theisen 2 , Ronald L. Hamilton 2 , Adrian V. Lee 3 and Adam M. Brufsky 3 1 Division of Hematology, Oncology and Blood & Marrow Transplantation, University of Iowa Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, Iowa City, IA, USA 2 Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA 3 Division of Hematology and Oncology, University of Pittsburgh, Pittsburgh, PA, USA Correspondence to: Jose Pablo Leone, email: // Keywords : breast cancer, brain metastasis, high affinity folate receptor, folate receptor alpha, metastatic breast cancer Received : April 22, 2015 Accepted : June 12, 2015 Published : June 25, 2015 Abstract High affinity folate receptor (HFR) can be overexpressed in breast cancer and is associated with poor prognosis, however the expression in breast cancer brain metastases (BCBM) is unknown. The aim of this study was to analyze the rate of HFR expression in BCBM and its role in the prognosis of this high-risk cohort. We analyzed 19 brain metastasis (BM) and 13 primary tumors (PT) from a total of 25 patients. HFR status was assessed by immunohistochemistry. Median follow-up was 4.2 years (range 0.6-18.5). HFR was positive in 4/19 BM (21.1%) and in 1/13 PT (7.7%). Positive samples had low H-scores (range 1-50). 56% of patients had apocrine differentiation. OS was similar between patients with positive HFR (median OS 48 months) and negative HFR (median OS 69 months) ( P = 0.25); and between patients with apocrine differentiation (median OS 63 months) and those without apocrine differentiation (median OS 69 months) ( P = 0.49). To the best of our knowledge, this is the first analysis of HFR expression in BCBM. While previous studies associated the presence of HFR with worse prognosis; in our cohort HFR was positive in only 21.1% of BM with low levels of positivity. Neither HFR nor apocrine features had impact in OS.