02.13 Clinical Relevance of Annexin A1 in Triple-negative Breast Cancer Patients

M. Okano1,2, H. Okayama1, T. Ohtake1, T. Kawaguchi2, L. Yan3, Q. Qi3, S. Liu3, K. Takabe2  1Fukushima Medical University School Of Medicine,Department Of Organ Regulatory Surgery,Fukushima, FUKUSHIMA, Japan 2Roswell Park Cancer Institute,Department Of Surgical Oncology,Buffalo, NY, USA 3Roswell Park Cancer Institute,Department Of Biostatistics & Bioinformatics,Buffalo, NY, USA

Introduction: Annexin A1 (ANXA1) is a calcium-dependent phospholipid-linked protein, involved in anti-inflammatory effects, regulation of cellular differentiation, proliferation and apoptosis. Recently, we reported that ANXA1 is associated with triple-negative breast cancer (TNBC) and its poor prognosis. Inhibition of programmed death-1 (PD-1) receptor/PD-1 ligand (PD-L1) was reported to suppress progression of TNBC. I In the present study, we evaluated the association between ANXA1 and PD-L1 expression in TNBC.

Methods: The ANXA1 and PD-L1 protein expression in the breast cancer (BrCa) tissues was assessed by IHC staining using an anti-ANXA1 and PD-L1 antibody in 48 TNBC patients and compared the levels with clinicopathological factors. We also validated the result using The Cancer Genome Atlas (TCGA) including RNA-seq data and clinical data.

Results:ANXA1 was positively expressed in 17 of the 48 cases (35.4%). Overall survival was significantly shorter in patients with ANXA1 positive tumors compared with ANXA1 negative tumor (p = 0.0082). No other clinicopathological factor was associated with ANXA1 expression. Utilizing TCGA dataset (n = 1060) for a validation study, high expression of ANXA1 associated with worse overall survival in TNBC patients (n = 111, p = 0.0459), while high expression of ANXA1 demonstrated conversely better overall survival in non-TNBC patients (n = 785, p = 0.0287). There was no survival difference with PD1 expression in our cohort, while high expression of PD-L1 associated with better prognosis in all BrCa patients in TCGA cohort (p = 0.0246). There was no association between ANXA1 and PD-L1 expression in the primary cohort, while high expression levels of ANXA1 demonstrated significant association with high PD-L1 expression in TCGA cohort (p < 0.0001).

Conclusion:These results suggested that ANXA1 is associated with poor prognosis of TNBC .