Fernández-Martínez, AranzazuAlbanell Mestres, JoanMartin, Miquel2018-07-092018-07-092017Fernandez-Martinez A, Pascual T, Perrone G, Morales S, de la Haba J, González-Rivera M. et al. Limitations in predicting PAM50 intrinsic subtype and risk of relapse score with Ki67 in estrogen receptor-positive HER2-negative breast cancer. Oncotarget. 2017 Mar 28;8(13):21930-21937. DOI: 10.18632/oncotarget.157481949-2553http://hdl.handle.net/10230/35067PAM50/Prosigna gene expression-based assay identifies three categorical risk of relapse groups (ROR-low, ROR-intermediate and ROR-high) in post-menopausal patients with estrogen receptor estrogen receptor-positive (ER+)/ HER2-negative (HER2-) early breast cancer. Low risk patients might not need adjuvant chemotherapy since their risk of distant relapse at 10-years is below 10% with endocrine therapy only. In this study, 517 consecutive patients with ER+/HER2- and node-negative disease were evaluated for Ki67 and Prosigna. Most of Luminal A tumors (65.6%) and ROR-low tumors (70.9%) had low Ki67 values (0-10%); however, the percentage of patients with ROR-medium or ROR-high disease within the Ki67 0-10% group was 42.7% (with tumor sizes ≤2 cm) and 33.9% (with tumor sizes > 2 cm). Finally, we found that the optimal Ki67 cutoff for identifying Luminal A or ROR-low tumors was 14%. Ki67 as a surrogate biomarker in identifying Prosigna low-risk outcome patients or Luminal A disease in the clinical setting is unreliable. In the absence of a well-validated prognostic gene expression-based assay, the optimal Ki67 cutoff for identifying low-risk outcome patients or Luminal A disease remains at 14%.application/pdfengCopyright : © 2017 Fernández-Martinez et al. This article is distributed under the terms of the https://creativecommons.org/licenses/by/3.0/ (CC-BY), which permits unrestricted use and redistribution provided that the original author and source are credited.Mama -- CàncerEstrògens -- Receptorsinfo:eu-repo/semantics/articlehttp://dx.doi.org/10.18632/oncotarget.15748Ki67PAM50/ProsignaBreast cancerEstrogen receptor-positive/HER2-negativeinfo:eu-repo/semantics/openAccess