胰腺癌及相关胰腺疾病组织中K-ras12、13密码子突变的检测及其临床诊断价值

Significance of quantitatively detecting K-ras codon 12 and 13 mutations in the tissues of pancreatic cancer and related pancreatic diseases

目的研究K-ras基因第12、13位密码子突变在胰腺导管腺癌及相关胰腺疾病组织中的定量检测及其临床意义。方法收集经手术切除的130例（胰腺导管腺癌105例，胰腺腺鳞癌8例，胰腺黏液腺癌2例，内分泌癌3例，十二指肠及壶腹部恶性肿瘤6例，胰腺良性疾病6例）有明确病理诊断的组织标本及临床资料，应用双荧光探针联合肽核酸钳制实时定量PCR方法检测组织中K-ras基因第12、13密码子的突变量，以突变量〉100拷贝为阳性计算突变阳性率。结果胰腺导管腺癌、腺鳞癌、黏液腺癌、内分泌癌、十二指肠及壶腹部恶性肿瘤、胰腺良性疾病的K-ras12密码子突变量的中位数及四分位数分别为4062（495，10800）、238（45，8420）、15（9，21）、3（3，16）、2283（73，5037）和21（8，56）；突变阳性率分别为84．8％（89／105）、50．0％（4／8）、0、0、66．7％（4／6）和16．7％（1／6）。胰腺导管腺癌的K-ras12密码子突变量及阳性率与胰腺腺鳞癌、十二指肠及壶腹部恶性肿瘤差异无统计学意义，而较胰腺黏液腺癌、内分泌癌、胰腺良性疾病显著增加（P值均〈0．05）。通过接受者操作特征（ROC）曲线分析，胰腺导管腺癌K-ras12密码子突变的曲线下面积为0．727，诊断胰腺导管腺癌的敏感性及特异性分别为84．8％、64．0％。胰腺导管腺癌的K-ras基因第12密码子突变量与患者生存期显著相关。胰腺导管腺癌的K-ras13密码子突变量及阳性率与其他胰腺疾病的差异无统计学意义。结论K-ras12密码子基因突变对胰腺癌有较好的鉴别诊断及患者预后判断价值。

Objective To investigate the clinical significance of quantitative detection of K-ras codon 12 and 13 mutations in the tissues of pancreatic cancer and related pancreatic diseases. Methods One hundred and thirty samples from surgically removed pancreatic tissue with a conclusive pathological diagnosis （105 cases of pancreatic ductal adcnocarcinoma, 8 cases of pancreatic adenosquamous carcinoma of the pancreas, 2 cases of pancreatic mucinous adenocarcinoma, 3 eases of pancreatic endocrine carcinoma, 6 cases of duodenal and papillary adenocarcinoma and 6 cases of benign pancreatic diseases ） were collected. Quantitative detection of K-ras codon 12 and 13 mutations was performed by the method of peptide nucleic acidmediated PCR clamping with two different fluorescence labeled probes. Mutation number 〉 100 copies was used as the criteria to calculate the positive mutation rate. Results The median and quartile of K-ras codon 12 mutations of pancreatic ductal adenocarcinoma, adenosquamous carcinoma of the pancreas, pancreatic mucinous adenocarcinoma, pancreatic endocrine carcinoma, duodenal and papillary adenocarcinoma and benign pancreatic diseases were 4062 （495, 10800）, 238 （45, 8420）, 15 （9, 21）, 3 （3, 16）, 2283 （73, 5037） and 21（8, 56）, and the positive mutation rates were 84.8% （89/105） ,50.0% （4/8）, 0, 0, 66.7% （4/6） and 16.7% （1/6）. The quantity of K-ras codon 12 mutation in pancreatic ductal adenocarcinoma was not statistically different from those of adenosquamous carcinoma, duodenal and papillary adenocarcinoma, but it was significantly higher than those in pancreatic mucinous adenocarcinoma, pancreatic endocrine carcinoma, and benign pancreatic diseases （P 〈0.05）. The area under ROC of K-ras codon 12 mutation in pancreatic ductal adenocarcinoma was 0. 727. The sensitivity and specificity of the K-ras codon 12 mutation for the diagnosis of pancreatic ductal adenocarcinoma were 84.8%, 64.0% , respectively. The quantity of K-ras codon 12 was associated with survival of patients with pancreatic ductal adenocarcinoma. The quantity of K-ras codon 13 mutations and the positive mutation rates in pancreatic ductal adenocarcinoma was not statistically different from other pancreatic diseases. Conclusions The quantity of K-ras codon 12 mutation has good differential diagnostic and prognostic prediction value for pancreatic ductal adenocarcinoma.