To assess circulating marker discrimination in training, testing and validation patient cohorts (total n=426 patients), plasma markers were measured among PDAC cases and patients with chronic pancreatitis, colorectal cancer (CRC), and healthy controls. Using CA19-9 as an anchor marker, measurements were made of two protein markers (TIMP1, LRG1) and cell-free DNA (cfDNA) pancreas-specific methylation at 9 loci encompassing 61 CpG sites.
Comparative methylome analysis identified nine loci that were differentially methylated in exocrine pancreas DNA. In the training set (n=124 patients), cfDNA methylation markers distinguished PDAC from healthy and CRC controls. In the testing set of 86 early stage PDAC and 86 matched healthy controls, CA19-9 had an area under the receiver operating characteristic curve (AUC) of 0.88 (95% CI 0.83 to 0.94), which was increased by adding TIMP1 (AUC 0.92; 95% CI 0.88 to 0.96; p=0.06), LRG1 (AUC 0.92; 95% CI 0.88 to 0.96; p=0.02) or exocrine pancreas-specific cfDNA methylation markers at nine loci (AUC 0.92; 95% CI 0.88 to 0.96; p=0.02). In the validation set of 40 early stage PDAC and 40 matched healthy controls, a combined panel including CA19-9, TIMP1 and a 9-loci cfDNA methylation panel had greater discrimination (AUC 0.86, 95% CI 0.77 to 0.95) than CA19-9 alone (AUC 0.82; 95% CI 0.72 to 0.92).
A combined panel of circulating markers including proteins and methylated cfDNA increased discrimination compared with CA19-9 alone for early stage PDAC.
方法:为了评估训练中的循环标记区分,测试和验证患者队列(总共n=426名患者),在PDAC病例和慢性胰腺炎患者中测量血浆标志物,结直肠癌(CRC),和健康的控制。使用CA19-9作为锚标记,对包含61个CpG位点的9个基因座的两个蛋白质标记(TIMP1,LRG1)和无细胞DNA(cfDNA)胰腺特异性甲基化进行了测量。
结果:比较甲基化组分析确定了胰腺外分泌DNA中差异甲基化的9个位点。在训练集中(n=124名患者),cfDNA甲基化标记区分PDAC与健康和CRC对照。在86个早期PDAC和86个匹配的健康对照的测试集中,CA19-9的受试者工作特征曲线下面积(AUC)为0.88(95%CI0.83至0.94),通过添加TIMP1增加(AUC0.92;95%CI0.88至0.96;p=0.06),LRG1(AUC0.92;95%CI0.88至0.96;p=0.02)或9个位点的外分泌胰腺特异性cfDNA甲基化标记(AUC0.92;95%CI0.88至0.96;p=0.02)。在40个早期PDAC和40个匹配的健康对照的验证集中,与单独使用CA19-9(AUC0.82;95%CI0.72~0.92)相比,包括CA19-9,TIMP1和9-基因座cfDNA甲基化组的组合组具有更大的鉴别(AUC0.86,95%CI0.77~0.95).
结论:对于早期PDAC,与单独使用CA19-9相比,包括蛋白质和甲基化cfDNA在内的一组循环标志物的组合增加了辨别。