胰腺癌高危人群外周血K-ras12密码子和K-ras13密码子突变的定量检测和意义

Quantitative detection and the significance of K-rasl2 and K-rasl3 mutations in peripheral blood of the population with high risk of pancreatic cancer

目的探讨胰腺癌高危人群外周血K—rasl2密码子和K—rasl3密码子突变量检测的临床价值。方法收集2010年5月至2011年11月有胰腺癌高危因素且诊断明确者160例，其中最终确诊胰腺癌36例，慢性胰腺炎（CP）36例，自身免疫性胰腺炎（AIP）6例，其他恶性肿瘤16例，胰腺良性肿瘤13例，胆总管结石13例，其他良性疾病40例。采集所有入选者的空腹外周静脉血，以肽核酸钳制实时荧光定量PCR法检测K—rasl2密码子和Krasl3密码子突变量。两组间突变量的比较采用Mann—WhitneyU检验，率的比较采用卡方检验。根据ROC曲线计算K—rasl2和K—rasl3突变阳性判定值和突变阳性率。结果胰腺癌组K—rasl2密码子突变量[i154（2207）]与其他良性疾病组[-476（973）]、CP组[-446（808）]、胆总管结石组[357（568）]比较差异均有统计学意义（u=502、446、117，P均d0．05）。胰腺癌组Krasl3密码子突变量与其他良性疾病组、CP组、胆总管结石组、AIP组、胰腺良性肿瘤组、其他恶性肿瘤组比较差异均无统计学意义（P均〉0．05）。K—rasl2密码子突变量〉i000拷贝为K—rasl2突变阳性判定值时，胰腺癌和非胰腺癌的K—rasl2突变阳性率分别为55．6％（20／s6）和25．0％（31／124），以K—rasl2突变鉴别胰腺癌和非胰腺癌的ROC曲线下面积为0．664，具鉴别诊断价值（P=0．003）。以K—rasl3突变鉴别胰腺癌与非胰腺癌的ROC曲线下面积为0．522，无鉴别诊断价值（P=0．695）。吸烟者和不吸烟者的K-ram3密码子突变量[分别为943（1510）和571（964）]差异有统计学意义（u=1779，P=0．010）。结论外周血Krasl2突变或可用于胰腺癌的筛查。

Objective To explore the clinical significance of the detection of K-rasl2 and K- rasl3 mutations in the peripheral blood of population with high risk group of pancreatic cancer. Methods From May 2010 to November 2011, a total of 160 patients with clear diagnosis and high risk of pancreatic cancer were collected. Among those patients, 36 cases were finally diagnosed as pancreatic cancer, 36 cases were chronic pancreatitis （CP）, six cases were autoimmune pancreatitis （AIP）, 16 cases were other malignant tumor, 13 cases were pancreatic benign tumor, 13 cases were bile duct stones and 40 cases were other benign diseases. Fasting peripheral venous blood was collected in all selected candidates. The condition of K-rasl2 and K-rasl3 mutation was detected by peptide nucleic acid-mediated real time fluorescen quantitative polymerase chain reaction. Mann-Whitney U test was performed to compare the mutation between the two groups. Chi-square test was used to compare the rates. According to the receiver operator characteristic （ROC） curve, the mutation positive decision value and the mutation positive rate of K-ras12 and K-ras13 were calculated. Results There were significant differences in K-ras12 mutation between pancreatic cancer group （1154 （2207）） and other benign diseases （476（973））, CP group （446（808））, bile duct stones group （357（568）） （U=502, 446 and 117,all P^0.05）. There were no significant differences in K-rasl3 mutation between pancreatic cancer group and other benign diseases, CP group, bile duct stones group （all P~〉0.05）. When the mutation positive decision value of K-rasl2 was set as mutation copy over 1000, the positive mutation rate of pancreatic cancer and non-pancreatic cancer was 55. 6~if00 （20/36） and 25. 0~ （31/124）, respectively. When the area under the ROC curve of K-ras12 was 0. 664, there was differential diagnostic value in identifying pancreatic cancer and non-pancreatic cancer （P=0. 003）. When the area under the ROC curve of K-rasl3 was 0. 522, there was no differential diagnostic value in identifying pancreatic cancer and non-pancreatic cancer （P= 0. 695）. There was significant difference in K-rasl3 mutation between smokers and non-smokers （943 （1510） and 571 （964））. Conclusion K-ras12 mutation in peripheral venous blood may be used for pancreatic cancer screening.