Institute of Pathology and Neuropathology, Eberhard-Karls-University Tuebingen and National Center for Pleura and Peritoneum, University of Tuebingen, Tuebingen, Germany.
Service of Clinical Pathology, Institute of Pathology, Lausanne University Hospital, Lausanne, Switzerland.
Histopathology. 2019 Jun;74(7):1014-1024. doi: 10.1111/his.13829. Epub 2019 Apr 14.
The four-tiered peritoneal regression grading score (PRGS) assesses the response to chemotherapy in peritoneal metastasis (PM). The PRGS is used, for example, to assess the response to pressurised intraperitoneal aerosol chemotherapy (PIPAC). However, the reproducibility of the PRGS is currently unknown. We aimed to evaluate the inter- and intraobserver variability of the PRGS.
Thirty-three patients who underwent at least three PIPAC treatments as part of the PIPAC-OPC1 or PIPAC-OPC2 clinical trials at Odense University Hospital, Denmark, were included. Prior to each therapy cycle, peritoneal quadrant biopsies were obtained and three haematoxylin and eosin (H&E)-stained step sections were scanned and uploaded to a pseudonymised web library. For determining interobserver variability, eight pathologists assessed the PRGS for each quadrant biopsy, and Krippendorff's alpha and intraclass correlation coefficients (ICCs) were calculated. For determining intraobserver variability, three pathologists repeated their own assessments and Cohen's kappa and ICCs were calculated. A total of 331 peritoneal biopsies were analysed. Interobserver variability for PRGS of each biopsy and for the mean and maximum PRGS per biopsy set was moderate to good/substantial. The intraobserver variability for PRGS of each biopsy and for the mean and maximum PRGS per biopsy set was good to excellent/almost perfect.
Our data support the PRGS as a reproducible and useful tool to assess response to intraperitoneal chemotherapy in PM. Future studies should evaluate the prognostic and predictive role of the PRGS.
四层次腹膜退缩分级评分（PRGS）评估了腹膜转移（PM）对化疗的反应。例如，PRGS 用于评估加压腹腔内气溶胶化疗（PIPAC）的反应。然而，PRGS 的可重复性目前尚不清楚。我们旨在评估 PRGS 的组内和组间观察者变异性。
33 例患者在丹麦奥胡斯大学医院接受了至少 3 次 PIPAC 治疗，这些患者参加了 PIPAC-OPC1 或 PIPAC-OPC2 临床试验。在每个治疗周期之前，均获得腹膜象限活检，并对 3 个苏木精和伊红（H&E）染色的连续切片进行扫描并上传到匿名化的网络库中。为了确定组间观察者变异性，8 位病理学家对每个象限活检的 PRGS 进行了评估，并计算了 Krippendorff's alpha 和组内相关系数（ICC）。为了确定组内观察者变异性，3 位病理学家重复了自己的评估，并计算了 Cohen's kappa 和 ICC。共分析了 331 个腹膜活检。每个活检的 PRGS 以及每个活检集的平均和最大 PRGS 的组间观察者变异性为中度至良好/实质性。每个活检的 PRGS 以及每个活检集的平均和最大 PRGS 的组内观察者变异性为良好至极好/几乎完美。
我们的数据支持 PRGS 作为一种可重复和有用的工具，用于评估 PM 中腹膜内化疗的反应。未来的研究应评估 PRGS 的预后和预测作用。
