Introduction

Mantle Cell Lymphoma (MCL), is characterised by the reciprocal translocation t(11;14) resulting in CCND1-IGH gene fusion and subsequent upregulation of the CCND1 gene. Rearrangements of MYC and losses of CDKN2A and TP53 have been identified as biomarkers informing prognostic and potentially therapeutic information however these are not routinely assessed in MCL investigation. We aimed to identify additional cytogenetic changes using fluorescence in situ hybridisation (FISH) on formalin fixed paraffin embedded (FFPE) primary lymph node tissue microarrays in a cohort of 28 patients diagnosed with MCL between 2004 and 2019. FISH results were compared with corresponding immunohistochemistry (IHC) biomarkers to determine if IHC was a reliable screening tool to direct FISH testing.

Method

FFPE lymph node tissue samples were constructed into tissue microarrays (TMA) which were stained with 7 immunohistochemical biomarkers: Cyclin D1, c-Myc, p16, ATM, p53, Bcl-6 and Bcl-2. The same TMAs were hybridised with FISH probes for the corresponding genes; CCND1-IGH, MYC, CDKN2A, ATM, TP53, BCL6 and BCL2. FISH and the corresponding IHC biomarkers were analysed to determine if secondary cytogenetic changes could be identified and if IHC could be used as a reliable, inexpensive predictor of FISH abnormalities to potentially direct FISH testing.

Results

CCND1-IGH fusion was detected in 27/28 (96%) of samples. Additional cytogenetic changes were identified by FISH in 15/28 (54%) of samples. Two additional abnormalities were detected in 2/28 (7%) samples. Cyclin D1 IHC overexpression was an excellent predictor of CCND1-IGH fusion. MYC and ATM IHC were useful screening tests to direct FISH testing and identified cases with poor prognostic features including blastoid change. IHC did not show clear concordance with FISH for other biomarkers.

Conclusion

FISH using FFPE primary lymph node tissue can detect secondary cytogenetic abnormalities in patients with MCL which are associated with an inferior prognosis. An expanded FISH panel including MYC, CDKN2A, TP53 and ATM should be considered in cases where anomalous IHC expression or is seen for these markers or if the patient appears to have the blastoid variant of the disease.

中文翻译：

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使用原发性淋巴结组织的 FFPE 组织微阵列进行综合 FISH 检测，确定套细胞淋巴瘤的继发性细胞遗传学异常

介绍

套细胞淋巴瘤 (MCL) 的特征在于相互易位 t(11;14)，导致CCND1-IGH基因融合和随后的CCND1基因上调。MYC的重排和CDKN2A和TP53的丢失已被确定为告知预后和潜在治疗信息的生物标志物，但这些在 MCL 研究中并未常规评估。我们的目的是在 2004 年至 2019 年间诊断为 MCL 的 28 名患者队列中使用荧光原位杂交 (FISH) 对福尔马林固定石蜡包埋 (FFPE) 原发性淋巴结组织微阵列进行额外的细胞遗传学变化。将 FISH 结果与相应的免疫组织化学进行了比较 ( IHC) 生物标志物以确定 IHC 是否是指导 FISH 检测的可靠筛选工具。

方法

将 FFPE 淋巴结组织样本构建成组织微阵列 (TMA)，用 7 种免疫组织化学生物标志物染色：细胞周期蛋白 D1、c-Myc、p16、ATM、p53、Bcl-6 和 Bcl-2。将相同的 TMA 与相应基因的 FISH 探针杂交；CCND1-IGH、MYC、CDKN2A、ATM、TP53、BCL6和BCL2。对 FISH 和相应的 IHC 生物标志物进行了分析，以确定是否可以识别继发性细胞遗传学变化，以及 IHC 是否可以用作 FISH 异常的可靠、廉价的预测指标，以潜在地指导 FISH 检测。

结果

在 27/28 (96%) 的样本中检测到 CCND1-IGH 融合。FISH 在 15/28 (54%) 的样本中发现了额外的细胞遗传学变化。在 2/28 (7%) 的样本中检测到另外两个异常。细胞周期蛋白 D1 IHC 过表达是CCND1-IGH融合的极好预测指标。MYC 和 ATM IHC 是有用的筛选测试，可指导 FISH 测试并确定具有不良预后特征（包括母细胞变化）的病例。对于其他生物标志物，IHC 未显示与 FISH 的明确一致性。

结论

使用 FFPE 原发性淋巴结组织的 FISH 可以检测 MCL 患者的继发性细胞遗传学异常，这些异常与较差的预后相关。如果 IHC 表达异常或发现这些标记物，或者患者似乎患有该疾病的母细胞变异，则应考虑扩展FISH 面板，包括MYC、CDKN2A、TP53和ATM 。