Nicholson A G, Perry L J, Cury P M, Jackson P, McCormick C M, Corrin B, Wells A U
Department of Histopathology, Royal Brompton Hospital, London, UK.
Histopathology. 2001 Mar;38(3):202-8. doi: 10.1046/j.1365-2559.2001.01078.x.
Although many workers have graded pre-invasive squamous lesions arising in the bronchus, there has been no consensus classification system until the latest edition of the WHO/IASLC histological classification of pulmonary and pleural tumours. Because the value of any such system is dependent on its reproducibility, we have circulated a series of such lesions to a panel of histopathologists to assess interobserver and intra-observer variation when the WHO/IASLC classification was applied.
Colour transparencies of 28 pre-invasive squamous lesions were assessed by six histopathologists (two with a special interest in pulmonary pathology, two generalists and two trainees) on three separate occasions over a period of 3 months, using the criteria of the WHO/IASLC (mild, moderate and severe dysplasia, and in-situ carcinoma). An additional category of metaplasia was added for those cases that showed no dysplasia. Weighted kappa coefficents of agreement (K(w)) were used to evaluate paired observations with a standard quadratic weighting being employed, such that kappa coefficients corresponded to intra-class correlation coefficients. Wilcoxon's sign-ranked test was used to measure the statistical significance of group trends, when comparing kappa values for the three grading systems. Various 3-point systems were also assessed, through combination of the above groups. Intra-observer agreement was substantially better than interobserver variation (mean: 0.71 vs. 0.55). Between the various pathologist groups, inter-observer variation was relatively minor, although intra-observer variation was higher within the trainee pathologist group. Using weighted kappa values, there was no significant difference in either inter-observer or intra-observer agreement between the five point grading system and a 3-point system of metaplasia/mild, moderate and severe/in-situ grades. However, there was a significant increase in variation when a 3-point system of metaplasia/mild, moderate/severe and in-situ carcinoma was used.
This study shows levels of interobserver and intra-observer variation similar to those found in other grading systems in histopathology, with no significant decrease in variability found by abridging the system. The WHO/IASLC system is therefore recommended for future use in both clinical and research fields.
尽管许多研究人员已对支气管中出现的浸润前鳞状病变进行了分级，但在世卫组织/国际肺癌研究协会（WHO/IASLC）最新版的肺和胸膜肿瘤组织学分类发布之前，一直没有统一的分类系统。由于任何此类系统的价值都取决于其可重复性，我们将一系列此类病变分发给一组组织病理学家，以评估应用WHO/IASLC分类时观察者间和观察者内的差异。
28例浸润前鳞状病变的彩色透明片由6位组织病理学家（2位对肺病理学有特殊兴趣，2位全科病理学家和2位实习医生）在3个月内分三次进行评估，采用WHO/IASLC的标准（轻度、中度和重度发育异常以及原位癌）。对于那些未显示发育异常的病例，增加了化生这一额外类别。使用加权kappa一致性系数（K(w)）来评估配对观察结果，采用标准二次加权，使得kappa系数对应于组内相关系数。在比较三种分级系统的kappa值时，使用Wilcoxon符号秩检验来衡量组趋势的统计学意义。还通过上述组的组合评估了各种三分制系统。观察者内一致性明显优于观察者间差异（平均值：0.71对0.55）。在不同病理学家组之间，观察者间差异相对较小，尽管实习医生组内观察者内差异较高。使用加权kappa值，五分制分级系统与化生/轻度、中度和重度/原位癌的三分制系统在观察者间或观察者内一致性方面均无显著差异。然而，当使用化生/轻度、中度/重度和原位癌的三分制系统时，差异显著增加。
本研究显示观察者间和观察者内差异水平与组织病理学中其他分级系统相似，简化系统并未显著降低变异性。因此，建议在未来的临床和研究领域中使用WHO/IASLC系统。
