Yábar Alejandro, Meléndez Rosa, Muñoz Silvia, Deneo Hugo, Freire Jimena, Domínguez Viviana, Carrasco-Navarro Roberto M, Diaz Maria E, Velarde-López Raúl E
Department of Pathology, Edgardo Rebagliatti Martins National Hospital, Lima, Perú.
Department of Pathology, Guillermo Almenara Irigoyen National Hospital, Lima, Perú.
Mol Clin Oncol. 2017 Apr;6(4):503-509. doi: 10.3892/mco.2017.1185. Epub 2017 Mar 8.
Breast cancer (BC) is a heterogeneous disease composed of four main subtypes with distinct clinical and epidemiological features. Although several reports have described the distribution of BC subtypes in Latin America, the majority of them have not included the cellular marker, Ki-67, in the immunohistochemical (IHC) panel. The aim of the present study was to describe the distribution of BC subtypes in a cohort of Latin American women using an IHC panel with Ki-67. A prospective cohort of 580 patients in three centers of Peru (the Hospital Nacional Edgardo Rebagliatti Martins, the Hospital Nacional Guillermo Almenara Irigoyen, the Hospital Nacional Alberto Sabogal, Lima) and one in Uruguay (Instituto Nacional del Cáncer, Montevideo) were evaluated. BC phenotypes were classified according to an IHC panel: Estrogen receptor (ER), progesterone receptor (PgR), HER2 and Ki-67. Silver hybridization was used when the HER2 status, as determined by IHC, was equivocal. The associations between the BC phenotypes and their clinicopathological features were evaluated. ER was positive in 65% of the cases (n=377), and PgR in 50% (n=203). In total, 79.1% (n=459) were HER2-negative, 19.8% (n=115) were HER2-positive and 1% (n=6) had an equivocal status. With respect to Ki-67, 44.7% of the patients exhibited staining in >14% of the tumor cells (n=259). The distribution of subtypes was as follows: Luminal A, 31.9% (n=183); luminal B, 35% (n=201); HER2, 12.1% (n=70); and triple-negative, 20.9% (n=120). When Ki-67 was not included in the panel, the frequency of luminal A was 41.1% and luminal B, 25.8% (9.2% of the cases were misclassified). Ki-67 was most highly expressed in triple-negative and HER2 tumors. Inclusion of Ki-67 in the IHC panel to assign subtypes revealed a higher frequency of luminal B tumors than was reported previously for Latin American women with BC, whereas the distribution of triple-negative and HER2 tumors were similar to that previously reported. In conclusion, these results demonstrated that excluding Ki-67 from the panel of IHC markers may lead to an underestimation of the rates of luminal B tumors.
乳腺癌（BC）是一种异质性疾病，由四种具有不同临床和流行病学特征的主要亚型组成。尽管有几份报告描述了拉丁美洲BC亚型的分布情况，但其中大多数在免疫组织化学（IHC）检测中未纳入细胞标志物Ki-67。本研究的目的是使用包含Ki-67的IHC检测来描述一组拉丁美洲女性中BC亚型的分布情况。对秘鲁三个中心（国立埃德加多·雷亚格利亚蒂·马丁斯医院、国立吉列尔莫·阿尔梅纳拉·伊里戈延医院、国立阿尔韦托·萨博加尔医院，利马）以及乌拉圭一个中心（国立癌症研究所，蒙得维的亚）的580例患者进行了前瞻性队列研究。根据IHC检测对BC表型进行分类：雌激素受体（ER）、孕激素受体（PgR）、HER2和Ki-67。当通过IHC确定的HER2状态不明确时，使用银染杂交法。评估了BC表型与其临床病理特征之间的关联。65%的病例（n = 377）ER呈阳性，50%（n = 203）的病例PgR呈阳性。总体而言，79.1%（n = 459）为HER2阴性，19.8%（n = 115）为HER2阳性，1%（n = 6）状态不明确。关于Ki-67，44.7%的患者肿瘤细胞染色率>14%（n = 259）。亚型分布如下：管腔A型，31.9%（n = 183）；管腔B型，35%（n = 201）；HER2型，12.1%（n = 70）；三阴性，20.9%（n = 120）。当检测中未纳入Ki-67时，管腔A型的频率为41.1%，管腔B型为25.8%（9.2%的病例被错误分类）。Ki-67在三阴性和HER2肿瘤中表达最高。在IHC检测中纳入Ki-67来划分亚型显示，管腔B型肿瘤的频率高于先前报道的拉丁美洲BC女性，而三阴性和HER2肿瘤的分布与先前报道相似。总之，这些结果表明，在IHC标志物检测中排除Ki-67可能导致管腔B型肿瘤发生率被低估。
