Khoury Thaer, Zirpoli Gary, Cohen Stephanie M, Geradts Joseph, Omilian Angela, Davis Warren, Bshara Wiam, Miller Ryan, Mathews Michelle M, Troester Melissa, Palmer Julie R, Ambrosone Christine B
Department of Pathology.
Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, NY.
Am J Clin Pathol. 2017 Aug 1;148(2):108-118. doi: 10.1093/ajcp/aqx053.
Ki-67 has been proposed to be used as a surrogate marker to differentiate luminal breast carcinomas (BCs). The purpose of this study was to determine the utility of and best approaches for using tissue microarrays (TMAs) and Ki-67 staining to distinguish luminal subtypes in large epidemiology studies of luminal/human epidermal growth factor receptor 2 (HER2)-negative BC.
Full-section and TMA (three 0.6-mm cores and two 1.0-mm cores) slides of 109 cases were stained with Ki-67 antibody. We assessed two ways of collapsing TMA cores: a weighted approach and mitotically active approach.
For cases with at least a single 0.6-mm TMA core (n = 107), 16% were misclassified using a mitotically active approach and 11% using a weighted approach. For cases with at least a single 1.0-mm TMA core (n = 101), 5% were misclassified using either approach. For the 0.6-mm core group, there were 33.3% discordant cases. The number of discordant cases increased from 18% in the group of two cores to 40% in the group of three cores (P = .039).
Ki-67 tumor heterogeneity was common in luminal/HER2- BC. Using a weighted approach was better than using a mitotically active approach for core to case collapsing. At least a single 1.0-mm core or three 0.6-mm cores are required when designing a study using TMA.
有人提出将Ki-67用作区分管腔型乳腺癌（BC）的替代标志物。本研究的目的是确定在管腔型/人表皮生长因子受体2（HER2）阴性BC的大型流行病学研究中，使用组织微阵列（TMA）和Ki-67染色来区分管腔亚型的实用性和最佳方法。
用Ki-67抗体对109例病例的全切片和TMA（三个0.6毫米芯块和两个1.0毫米芯块）玻片进行染色。我们评估了两种将TMA芯块合并的方法：加权法和有丝分裂活跃法。
对于至少有一个0.6毫米TMA芯块的病例（n = 107），使用有丝分裂活跃法时16%被错误分类，使用加权法时11%被错误分类。对于至少有一个1.0毫米TMA芯块的病例（n = 101），使用任何一种方法时5%被错误分类。对于0.6毫米芯块组，有33.3%的病例不一致。不一致病例的数量从两个芯块组的18%增加到三个芯块组的40%（P = .039）。
Ki-67肿瘤异质性在管腔型/HER2阴性BC中很常见。在将芯块合并到病例时，使用加权法比使用有丝分裂活跃法更好。在设计使用TMA的研究时，至少需要一个1.0毫米芯块或三个0.6毫米芯块。
