Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Department of Cancer Molecular Diagnostics, St. James's Hospital, Dublin, Ireland; Department of Histopathology, St. James's Hospital, Dublin, Ireland.
Department of PCR IVD Research and Early Development, Roche Molecular Systems, Inc., Pleasanton, California.
J Mol Diagn. 2021 Mar;23(3):323-340. doi: 10.1016/j.jmoldx.2020.11.013. Epub 2020 Dec 29.
Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. Cell-of-origin classification in DLBCL has identified activated B cell (ABC) and germinal center B cell (GCB) as two major subtypes. Patients with the ABC subtype show reduced overall survival with standard therapies. Development of a quantitative RT-PCR-based lymphoma cell-of-origin (LCOO) assay to determine ABC, GCB, and unclassifiable subtypes in formalin-fixed, paraffin-embedded tissue (FFPET) DLBCL samples is reported. The LCOO classifier was trained on two DLBCL cohorts with validation performed by using an analytical grade assay in an independent cohort of 60 FFPET DLBCL samples. In the validation cohort, LCOO classification was 88.1%, 84.7%, and 84.7% concordant with microarray, immunohistochemistry (Hans classification), and Lymphoma Subtyping Test, respectively. Importantly, LCOO and Lymphoma Subtyping Test assays commonly assigned subtypes in 17 (94.4%) of 18 ABC samples and 34 (89.5%) of 38 GCB DLBCL samples from this cohort. Progression-free survival and overall survival of ABC and GCB subtypes, as classified by all platforms, were not significantly different in the validation cohort. LCOO classification using publicly available microarray gene expression from two independent data sets (414 fresh frozen and 474 FFPET DLBCL biopsies) revealed a significantly worse outcome for the ABC subtype compared with that of the GCB subtype. Thus, a sensitive, reproducible, LCOO assay developed on an easy to standardize quantitative RT-PCR platform may be an important clinical tool for DLBCL cell-of-origin classification.
弥漫性大 B 细胞淋巴瘤（DLBCL）是一种异质性疾病。在 DLBCL 中，细胞起源分类已确定激活 B 细胞（ABC）和生发中心 B 细胞（GCB）为两种主要亚型。接受标准疗法治疗的 ABC 亚型患者的总生存期降低。本研究报告了一种基于定量 RT-PCR 的淋巴瘤细胞起源（LCOO）检测方法的开发，用于确定福尔马林固定石蜡包埋组织（FFPET）DLBCL 样本中的 ABC、GCB 和不可分类亚型。LCOO 分类器在两个 DLBCL 队列中进行了训练，并在 60 个 FFPET DLBCL 样本的独立队列中使用分析级别的测定进行了验证。在验证队列中，LCOO 分类与微阵列、免疫组织化学（Hans 分类）和淋巴瘤分型测试的一致性分别为 88.1%、84.7%和 84.7%。重要的是，LCOO 和淋巴瘤分型测试检测方法在该队列的 17 个（94.4%）ABC 样本和 34 个（89.5%）GCB DLBCL 样本中通常分配了亚型。在验证队列中，所有平台分类的 ABC 和 GCB 亚型的无进展生存期和总生存期无显著差异。使用两个独立数据集（414 个新鲜冷冻和 474 个 FFPET DLBCL 活检）的公开可用微阵列基因表达数据进行的 LCOO 分类显示，与 GCB 亚型相比，ABC 亚型的结局明显较差。因此，基于易于标准化的定量 RT-PCR 平台开发的敏感、可重复的 LCOO 检测方法可能是 DLBCL 细胞起源分类的重要临床工具。
