start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=6 article-no= start-page=1617 end-page=1621 dt-received= dt-revised= dt-accepted= dt-pub-year=2017 dt-pub=20170625 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Molecular Subtypes of Breast Cancers from Myanmar Women: A Study of 91 Cases at Two Pathology Centers en-subtitle= kn-subtitle= en-abstract= kn-abstract= BACKGROUND: Breast cancer is the most common cancer in Myanmar women. Revealing the hormonal receptor status, human epidermal growth factor receptor 2 (HER2) and Ki-67 expression is useful for estimating patient prognosis as well as determination of treatment strategy. However, immunohistochemical features and classification of molecular subtypes in breast cancers from Myanmar remain unknown. METHODS: The clinicopathological features of 91 breast cancers from Myanmar women were examined. Immunohistochemistry was performed on tissue specimens with antibodies to estrogen receptor (ER), progesterone receptor (PgR), HER2, Ki-67, cytokeratin (CK)5/6 and CK14. Immunohistochemistry-based molecular subtyping was conducted. RESULTS: Breast cancers in Myanmar women were relatively large, high grade with frequent metastatic lymph nodes. Of the 91 patients, tumors with ER positive, PgR positive, and HER2 positive were 57.1%, 37.4%, and 28.6%, respectively. The most prevalent subtype was luminal B (HER2-) (39.6%), followed by HER2 (22.0%), triple negative (TN)-basal-like (12.1%), luminal A (11.0%), TN-null (8.8%) and luminal B (HER2+) (6.6%). The mean Ki-67 expression of 91 cases was 33.9% (33.9% } 19.2%) and the median was 28% (range; 4%-90%). The mean Ki-67 expression of luminal A, luminal B, HER2 and TN-basal-like/ null was 7%, 30%, 40%, and 57%/43%, respectively. A higher Ki-67 expression significantly correlated with a higher grade, larger size and higher stage of malignancy. CONCLUSIONS: We, for the first time, investigated the histopathological features of breast cancers from Myanmar women. Myanmar breast cancers appeared to be aggressive in nature, as evidenced by high frequency of poor-prognosis subtypes with high level of Ki-67 expression. en-copyright= kn-copyright= en-aut-name=Thar Htet San en-aut-sei=Thar Htet San en-aut-mei= kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=FujisawaMasayoshi en-aut-sei=Fujisawa en-aut-mei=Masayoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FushimiSoichiro en-aut-sei=Fushimi en-aut-mei=Soichiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SoeLamin en-aut-sei=Soe en-aut-mei=Lamin kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=Ngu Wah Min en-aut-sei=Ngu Wah Min en-aut-mei= kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=YoshimuraTeizo en-aut-sei=Yoshimura en-aut-mei=Teizo kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=OharaToshiaki en-aut-sei=Ohara en-aut-mei=Toshiaki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=Myint Myint Yee en-aut-sei=Myint Myint Yee en-aut-mei= kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=OdaShinsuke en-aut-sei=Oda en-aut-mei=Shinsuke kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=Matsukawa Akihiro en-aut-sei=Matsukawa en-aut-mei=Akihiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= affil-num=1 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Department of Pathology, Myeik General Hospital kn-affil= affil-num=5 en-affil=Department of Pathology, Sakura Specialist Hospital kn-affil= affil-num=6 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=7 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=8 en-affil=Department of Pathology, Central Women Hospital kn-affil= affil-num=9 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=10 en-affil=Department of Pathology and Experimental Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=Breast cancer kn-keyword=Breast cancer en-keyword=molecular subtypes kn-keyword=molecular subtypes en-keyword=Ki-67 expression kn-keyword=Ki-67 expression en-keyword=Myanmar kn-keyword=Myanmar END