Comment to “Patients with Concordant Triple-Negative Phenotype between Primary Breast Cancers and Corresponding Metastases Have Poor Prognosis”

http://ejbc.kr | pISSN 1738-6756 eISSN 2092-9900 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. To the Editor, I read the article by Shin et al. [1] regarding the prognostic impact of discordance between the receptor status of primary breast cancers and corresponding metastases. They concluded that patients with concordant triple-negative phenotype (TNP) had worse long-term outcomes than patients with concordant non-TNP and discordant TNP in a comparison of primary and metastatic breast cancer. As described in the “Methods” section, the cutoff value for estrogen receptor and progesterone receptor positivity was ≥ 10% of tumor cells positive for nuclear staining. However, in the literature, many studies on TNP describe hormone receptor status with different cutoff values [2,3]. Furthermore, the American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) recommended that a cutoff of 1% positive cells be used to define estrogen receptor-positive status [4]. In conclusion, for better interpretation of studies related to TNP, as in the case of the definition of human epidermal growth factor receptor 2 status, internationally accepted defined cutoff values for hormone receptors are urgently needed.