Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, Minnesota.
Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
Clin Cancer Res. 2021 May 1;27(9):2523-2532. doi: 10.1158/1078-0432.CCR-20-0235. Epub 2021 Feb 16.
We have previously identified tissue methylated DNA markers (MDMs) associated with pancreatic ductal adenocarcinoma (PDAC). In this case-control study, we aimed to assess the diagnostic performance of plasma MDMs for PDAC.
Thirteen MDMs (, and ) were identified on the basis of selection criteria applied to results of prior tissue experiments and assays were optimized in plasma. Next, 340 plasma samples (170 PDAC cases and 170 controls) were assayed using target enrichment long-probe quantitative amplified signal method. Initially, 120 advanced-stage PDAC cases and 120 healthy controls were used to train a prediction algorithm at 97.5% specificity using random forest modeling. Subsequently, the locked algorithm derived from the training set was applied to an independent blinded test set of 50 early-stage PDAC cases and 50 controls. Finally, data from all 340 patients were combined, and cross-validated.
The cross-validated area under the receiver operating characteristic curve (AUC) for the training set was 0.93 (0.89-0.96) for the MDM panel alone, 0.91 (95% confidence interval, 0.87-0.96) for carbohydrate antigen 19-9 (CA19-9) alone, and 0.99 (0.98-1) for the combined MDM-CA19-9 panel. In the test set of early-stage PDAC, the AUC for MDMs alone was 0.84 (0.76-0.92), CA19-9 alone was 0.87 (0.79-0.94), and combined MDM-CA19-9 panel was 0.90 (0.84-0.97) significantly better compared with either MDMs alone or CA19-9 alone ( = 0.0382 and 0.0490, respectively). At a preset specificity of 97.5%, the sensitivity for the combined panel in the test set was 80% (28%-99%) for stage I disease and 82% (68%-92%) for stage II disease. Using the combined datasets, the cross-validated AUC was 0.9 (0.86-0.94) for the MDM panel alone and 0.89 for CA19-9 alone (0.84-0.93) versus 0.97 (0.94-0.99) for the combined MDM-CA19-9 panel ( ≤ 0.0001). Overall, cross-validated sensitivity of MDM-CA19-9 panel was 92% (83%-98%), with an observed specificity of 92% at the preset specificity of 97.5%.
Plasma MDMs in combination with CA19-9 detect PDAC with significantly higher accuracy compared with either biomarker individually.
我们之前已经确定了与胰腺导管腺癌（PDAC）相关的组织甲基化 DNA 标志物（MDM）。在本病例对照研究中，我们旨在评估血浆 MDM 对 PDAC 的诊断性能。
基于先前组织实验结果应用的选择标准，确定了 13 个 MDM（、和），并对其进行了优化在血浆中进行测定。接下来，使用目标富集长探针定量扩增信号法对 340 个血浆样本（170 例 PDAC 病例和 170 例对照）进行了检测。最初，使用随机森林建模在 97.5%特异性的条件下使用 120 例晚期 PDAC 病例和 120 例健康对照来训练预测算法。随后，将从训练集得出的锁定算法应用于 50 例早期 PDAC 病例和 50 例对照的独立盲法测试集。最后，对所有 340 例患者的数据进行了组合和交叉验证。
训练集的交叉验证受试者工作特征曲线（ROC）下面积（AUC）为单独 MDM 面板为 0.93（0.89-0.96），单独 CA19-9 为 0.91（95%置信区间，0.87-0.96）），以及联合 MDM-CA19-9 面板为 0.99（0.98-1）。在早期 PDAC 的测试集中，单独 MDM 的 AUC 为 0.84（0.76-0.92），CA19-9 为 0.87（0.79-0.94），联合 MDM-CA19-9 面板为 0.90（0.84-0.97））明显优于单独 MDM 或 CA19-9（=0.0382 和 0.0490）。在预设特异性为 97.5%的情况下，测试集中联合面板的灵敏度为 I 期疾病的 80%（28%-99%）和 II 期疾病的 82%（68%-92%）。使用联合数据集，单独 MDM 面板的交叉验证 AUC 为 0.9（0.86-0.94），CA19-9 为 0.89（0.84-0.93），而联合 MDM-CA19-9 面板为 0.97（0.94-0.99）（≤0.0001）。总体而言，MDM-CA19-9 面板的交叉验证灵敏度为 92%（83%-98%），观察到的特异性为 92%，在预设特异性为 97.5%的情况下。
与单独的生物标志物相比，血浆 MDM 与 CA19-9 的联合检测对 PDAC 的检测具有更高的准确性。
