PMID- 32055918 OWN - NLM STAT- MEDLINE DCOM- 20200508 LR - 20240426 IS - 1432-0851 (Electronic) IS - 0340-7004 (Print) IS - 0340-7004 (Linking) VI - 69 IP - 5 DP - 2020 May TI - Co-expression of HLA-I loci improved prognostication in HER2+ breast cancers. PG - 799-811 LID - 10.1007/s00262-020-02512-z [doi] AB - The underlying basis for cancer immune evasion is important for effective immunotherapy and prognosis in breast cancers. Human leucocyte antigens (HLA)-I comprising three classical antigens (HLA-A, -B and -C) is mandatory for anti-tumor immunity. Its loss occurred frequently in many cancers resulting in effective immune evasion. Most studies examined HLA-I as a whole. Alterations in specific locus could have different clinical ramifications. Hence, we evaluated the expression of the three HLA-I loci in a large cohort of breast cancers. Low expression of HLA-A, -B and -C were found in 71.1%, 66.3%, and 60.2% of the cases. Low and high expression in all loci was found in 48.3% and 17.9% of the cases respectively. The remaining showed high expression in one or two loci. Cases with all HLA high expression (all HLA high) was frequent in the ER-HER2- (27.4%) and ER-HER2+ (23.1%) cases and was associated with characteristic pathologic features related to these tumor (higher grade, necrosis, high tumor infiltrating lymphocyte (TIL), pT stage, low hormonal receptor, high basal marker expression) (p