Fulawka Lukasz, Halon Agnieszka
Department of Pathology, Lower Silesian Oncology Centre; Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Wroclaw, Poland.
Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Wroclaw, Poland.
Indian J Pathol Microbiol. 2017 Apr-Jun;60(2):177-184. doi: 10.4103/IJPM.IJPM_732_15.
Breast cancer is the most common malignancy in females. It is routinely classified according to the WHO histological typing. However, there is also a molecular classification of breast cancer which is routinely substituted with surrogate subtypes based on expression of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors and proliferation index (PI). PI is defined as the percentage of Ki-67-positive cells among overall cell population. The method commonly applied by pathologists to determine PI is visual scoring of the sample. Strict recommendations for PI assessment do not exist. Thus, the mode of PI evaluation differs significantly between pathologists.
The aim of our study was to evaluate the daily approach to defining the PI.
Four practicing nonscholar pathologists were asked to evaluate PI in cases of invasive breast carcinoma.
The study was performed on a group of 98 patients diagnosed with invasive breast carcinoma. Immunohistochemical reaction was performed with monoclonal antibody against human Ki-67 antigen using Ventana BenchMark XT.
Results were compared using Pearson's and Spearman's rank correlation coefficients and Fleiss and Cohen's kappa values.
Statistical analysis showed pairwise Pearson's coefficients ranging between 0.77 and 0.84 (P < 0.001) and Spearman's rank correlation coefficients ranging between 0.68 and 0.83 (P < 0.001). The Fleiss kappa value for the 14% cutoff point was 0.58 whereas for the 20% cutoff point was 0.60. The pairwise Cohen's kappa values ranged from 0.45 to 0.69 for the 14% cutoff point and 0.53 to 0.67 for the 20% cutoff point. Friedman's rank ANOVA test showed significant differences among the four pathologists (P < 0.001).
Our study shows a significant difference in results and methods of evaluation of PI between pathologists.
乳腺癌是女性中最常见的恶性肿瘤。它通常根据世界卫生组织的组织学分类进行分类。然而，也存在乳腺癌的分子分类，该分类通常基于雌激素、孕激素和人表皮生长因子受体2受体的表达以及增殖指数（PI）被替代为替代亚型。PI被定义为Ki-67阳性细胞在总细胞群体中的百分比。病理学家确定PI的常用方法是对样本进行视觉评分。不存在关于PI评估的严格建议。因此，病理学家之间PI评估的方式差异很大。
我们研究的目的是评估定义PI的日常方法。
邀请四位执业非学者病理学家评估浸润性乳腺癌病例中的PI。
该研究对一组98例诊断为浸润性乳腺癌的患者进行。使用Ventana BenchMark XT对人Ki-67抗原的单克隆抗体进行免疫组织化学反应。
使用Pearson和Spearman等级相关系数以及Fleiss和Cohen卡方值比较结果。
统计分析显示成对Pearson系数在0.77至0.84之间（P < 0.001），Spearman等级相关系数在0.68至0.83之间（P < 0.001）。14%截断点的Fleiss卡方值为0.58，而20%截断点的为0.60。14%截断点的成对Cohen卡方值范围为0.45至0.69，20%截断点的为0.53至0.67。Friedman秩方差分析检验显示四位病理学家之间存在显著差异（P < 0.001）。
我们的研究表明病理学家在PI评估结果和方法上存在显著差异。
