Precision Oncology Hub, Department of Oncology, University of Calgary, Tom Baker Cancer Centre, Calgary, AB, Canada.
Department of Pathology and Laboratory Medicine, University of Calgary, Foothills Medical Center, Calgary, AB, Canada.
J Pathol Clin Res. 2020 Oct;6(4):252-262. doi: 10.1002/cjp2.168. Epub 2020 May 11.
CCNE1 amplification is a recurrent alteration associated with unfavourable outcome in tubo-ovarian high-grade serous carcinoma (HGSC). We aimed to investigate whether immunohistochemistry (IHC) can be used to identify CCNE1 amplification status and to validate whether CCNE1 high-level amplification and overexpression are prognostic in HGSC. A testing set of 528 HGSC samples stained with two optimised IHC assays (clones EP126 and HE12) was subjected to digital image analysis and visual scoring. DNA and RNA chromogenic in situ hybridisation for CCNE1 were performed. IHC cut-off was determined by receiver operating characteristics (ROC). Survival analyses (endpoint ovarian cancer specific survival) were performed and validated in an independent validation set of 764 HGSC. Finally, combined amplification/expression status was evaluated in cases with complete data (n = 1114). CCNE1 high-level amplification was present in 11.2% of patients in the testing set and 10.2% in the combined cohort. The optimal cut-off for IHC to predict CCNE1 high-level amplification was 60% positive tumour cells with at least 5% strong staining cells (sensitivity 81.6%, specificity 77.4%). CCNE1 high-level amplification and overexpression were associated with survival in the testing and validation set. Combined CCNE1 high-level amplification and overexpression was present in 8.3% of patients, mutually exclusive to germline BRCA1/2 mutation and significantly associated with a higher risk of death in multivariate analysis adjusted for age, stage and cohort (hazard ratio = 1.78, 95 CI% 1.38-2.26, p < 0.0001). CCNE1 high-level amplification combined with overexpression identifies patients with a sufficiently poor prognosis that treatment alternatives are urgently needed. Given that this combination is mutually exclusive to BRCA1/2 germline mutations, a predictive marker for PARP inhibition, CCNE1 high-level amplification combined with overexpression may serve as a negative predictive test for sensitivity to PARP inhibitors.
CCNE1 扩增是与管状卵巢高级别浆液性癌 (HGSC) 不良预后相关的常见改变。我们旨在研究免疫组织化学 (IHC) 是否可用于识别 CCNE1 扩增状态，并验证 CCNE1 高水平扩增和过表达是否在 HGSC 中具有预后价值。使用两种优化的 IHC 检测（克隆 EP126 和 HE12）对 528 例 HGSC 样本进行染色，并进行数字图像分析和视觉评分。进行 CCNE1 的 DNA 和 RNA 显色原位杂交。通过接收者操作特征 (ROC) 确定 IHC 截断值。在 764 例 HGSC 的独立验证集中进行生存分析（终点卵巢癌特异性生存），并进行验证。最后，在具有完整数据的病例中评估联合扩增/表达状态（n = 1114）。在检测集中，11.2%的患者存在 CCNE1 高水平扩增，在联合队列中为 10.2%。IHC 预测 CCNE1 高水平扩增的最佳截断值为 60%阳性肿瘤细胞，至少有 5%强染色细胞（敏感性 81.6%，特异性 77.4%）。CCNE1 高水平扩增和过表达与检测和验证集中的生存相关。在检测和验证集中，联合 CCNE1 高水平扩增和过表达存在于 8.3%的患者中，与种系 BRCA1/2 突变相互排斥，并且在调整年龄、分期和队列后多变量分析中与死亡风险增加显著相关（危险比 = 1.78，95%CI%1.38-2.26，p < 0.0001）。CCNE1 高水平扩增联合过表达可识别出预后较差的患者，迫切需要治疗选择。鉴于这种组合与种系 BRCA1/2 突变相互排斥，PARP 抑制剂的预测标志物，CCNE1 高水平扩增联合过表达可能作为 PARP 抑制剂敏感性的阴性预测试验。
