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 [23]. 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.