Unidade Integrada de Patologia Especializada (UniPE), Postgraduate Program in Pathology, Pathological Anatomy Service of Hospital Universitário Antônio Pedro, Universidade Federal Fluminense, Niterói, RJ, 23033-900, Brazil.
Department of Pathology, School of Medicine, Universidade Federal Fluminense, Niterói, RJ, Brazil.
Virchows Arch. 2021 Jul;479(1):121-131. doi: 10.1007/s00428-020-03010-4. Epub 2021 Jan 19.
The Ki-67 labeling index is traditionally used to investigate tumor aggressiveness. However, no diagnostic or prognostic value has been associated to the heterogeneous pattern of nuclear positivity. The aims of this study were to develop a classification for the patterns of Ki-67-positive nuclei; to search scientific evidence for the Ki-67 expression and location throughout the cell cycle; and to develop a protocol to apply the classification of patterns of Ki-67-positive nuclei in squamous epithelium with different proliferative activities. Based on empirical observation of paraffin sections submitted to immunohistochemistry for the determination of Ki-67 labeling index and literature review about Ki-67 expression, we created a classification of the patterns of nuclear positivity (NP1, NP2, NP3, NP4, and mitosis). A semi-automatic protocol was developed to identify and quantify the Ki-67 immunostaining patterns in target tissues. Two observers evaluated 7000 nuclei twice to test the intraobserver reliability, and six evaluated 1000 nuclei to the interobserver evaluation. The results showed that the immunohistochemical patterns of Ki-67 are similar in the tumoral and non-tumoral epithelium and were classified without difficulty. There was a high intraobserver reliability (Spearman correlation coefficient > 0.9) and moderate interobserver agreement (k = 0.523). Statistical analysis showed that non-malignant epithelial specimens presented a higher number of NP1 (geographic tongue = 83.8 ± 21.8; no lesion = 107.6 ± 52.7; and mild dysplasia = 86.6 ± 25.8) when compared to carcinoma in Situ (46.8 ± 34.8) and invasive carcinoma (72.6 ± 37.9). The statistical evaluation showed significant difference (p < 0.05). Thus, we propose a new way to evaluate Ki-67, where the pattern of its expression may be associated with the dynamics of the cell cycle. Future proof of this association will validate the use of the classification for its possible impact on cancer prognosis and guidance on personalized therapy.
Ki-67 标记指数传统上用于研究肿瘤侵袭性。然而，核阳性的异质性模式与任何诊断或预后价值均无关。本研究的目的是开发一种核 Ki-67 阳性细胞的分类方法；寻找 Ki-67 表达及其在细胞周期中位置的科学依据；并制定一种方案，将 Ki-67 阳性细胞核模式的分类应用于具有不同增殖活性的鳞状上皮。基于对用于确定 Ki-67 标记指数的免疫组织化学石蜡切片的经验观察和对 Ki-67 表达的文献回顾，我们创建了核阳性模式的分类（NP1、NP2、NP3、NP4 和有丝分裂）。开发了一种半自动方案来识别和量化目标组织中的 Ki-67 免疫染色模式。两名观察者两次评估了 7000 个细胞核以测试观察者内可靠性，六名观察者评估了 1000 个细胞核以测试观察者间的评估。结果表明，肿瘤和非肿瘤上皮的 Ki-67 免疫组化模式相似，易于分类。观察者内可靠性很高（Spearman 相关系数 > 0.9），观察者间一致性中等（k = 0.523）。统计分析表明，非恶性上皮标本的 NP1 数量较高（地理舌 = 83.8 ± 21.8；无病变 = 107.6 ± 52.7；轻度发育不良 = 86.6 ± 25.8），与原位癌（46.8 ± 34.8）和浸润性癌（72.6 ± 37.9）相比。统计学评估显示差异有统计学意义（p < 0.05）。因此，我们提出了一种新的 Ki-67 评估方法，其表达模式可能与细胞周期动力学有关。这种关联的进一步证明将验证分类的使用，因为其可能对癌症预后产生影响，并指导个性化治疗。
