Salek C, Benesova L, Zavoral M, Nosek V, Kasperova L, Ryska M, Strnad R, Traboulsi E, Minarik M
Laboratory for Molecular Genetics and Oncology, Genomac International Ltd., Bavorska 856, 15541 Prague 5, Czech Republic.
World J Gastroenterol. 2007 Jul 21;13(27):3714-20. doi: 10.3748/wjg.v13.i27.3714.
To establish an optimum combination of molecular markers resulting in best overall diagnostic sensitivity and specificity for evaluation of suspicious pancreatic mass.
Endoscopic ultrasound (EUS)-guided fine needle aspiration cytology (FNA) was performed on 101 consecutive patients (63 males, 38 females, 60 +/- 12 years; 81 with subsequently diagnosed pancreatic cancer, 20 with chronic pancreatitis) with focal pancreatic mass. Samples were evaluated on-site by an experienced cytopathologist. DNA was extracted from Giemsa stained cells selected by laser microdissection and the presence of K-ras, p53 and p16 somatic mutations was tested by cycling-gradient capillary electrophoresis (CGCE) and single-strand conformation polymorphism (SSCP) techniques. In addition, allelic losses of tumor suppressor genes p16 (INK4, CDKN2A) and DPC4 (MADH4, SMAD4) were detected by monitoring the loss of heterozygosity (LOH) at 9p and 18q, respectively.
Sensitivity and specificity of EUS-guided FNA were 75% and 85%, positive and negative predictive value reached 100%. The remaining 26% samples were assigned as inconclusive. Testing of molecular markers revealed sensitivity and specificity of 70% and 100% for K-ras mutations (P < 0.001), 24% and 90% for p53 mutations (NS), 13% and 100% for p16 mutations (NS), 85% and 64% for allelic losses at 9p (P < 0.001) and 78% and 57% for allelic losses at 18q (P < 0.05). When tests for different molecular markers were combined, the best results were obtained with K-ras + LOH at 9p (92% and 64%, P < 0.001), K-ras + LOH at 18q (92% and 57%, P < 0.001), and K-ras + LOH 9q + LOH 18q (96% and 43%, P < 0.001). When the molecular markers were used as complements to FNA cytology to evaluate inconclusive samples only, the overall sensitivity of cancer detection was 100% in all patients enrolled in the study.
EUS-guided FNA cytology combined with screening of K-ras mutations and allelic losses of tumor suppressors p16 and DPC4 represents a very sensitive approach in screening for pancreatic malignancy. Molecular markers may find its use particularly in cases where FNA cytology has been inconclusive.
建立一组最佳分子标志物组合，以获得评估可疑胰腺肿块时总体诊断敏感性和特异性的最佳效果。
对101例有局灶性胰腺肿块的连续患者（63例男性，38例女性，年龄60±12岁；81例随后被诊断为胰腺癌，20例为慢性胰腺炎）进行内镜超声（EUS）引导下细针穿刺细胞学检查（FNA）。样本由经验丰富的细胞病理学家进行现场评估。从经激光显微切割选择的吉姆萨染色细胞中提取DNA，采用循环梯度毛细管电泳（CGCE）和单链构象多态性（SSCP）技术检测K-ras、p53和p16体细胞突变的存在。此外，分别通过监测9p和18q处杂合性缺失（LOH）来检测肿瘤抑制基因p16（INK4，CDKN2A）和DPC4（MADH4，SMAD4）的等位基因缺失。
EUS引导下FNA的敏感性和特异性分别为75%和85%，阳性和阴性预测值均达到100%。其余26%的样本被判定为不确定。分子标志物检测显示，K-ras突变的敏感性和特异性分别为70%和100%（P<0.001），p53突变的敏感性和特异性分别为24%和90%（无统计学意义），p16突变的敏感性和特异性分别为13%和100%（无统计学意义），9p处等位基因缺失的敏感性和特异性分别为85%和64%（P<0.001），18q处等位基因缺失的敏感性和特异性分别为78%和57%（P<0.05）。当不同分子标志物检测结果联合使用时，K-ras + LOH 9p组合获得最佳结果（92%和64%，P<0.001），K-ras + LOH 18q组合（92%和57%，P<0.001），以及K-ras + LOH 9q + LOH 18q组合（96%和43%，P<0.001）。当分子标志物仅作为FNA细胞学的补充用于评估不确定样本时，则本研究中所有患者的癌症总体检测敏感性为100%。
EUS引导下FNA细胞学检查联合K-ras突变筛查以及肿瘤抑制因子p16和DPC4的等位基因缺失检测是筛查胰腺恶性肿瘤的一种非常敏感的方法。分子标志物尤其在FNA细胞学检查结果不确定的病例中可能有用。
