卵巢恶性肿瘤患者血浆游离DNA含量测定及临床意义

Determination of free DNA level in plasma of patients with ovarian cancer

目的：检测卵巢恶性肿瘤患者血浆游离DNA的含量并探讨其临床应用价值。方法：采集30例卵巢恶性肿瘤、20例卵巢良性肿瘤患者及20例健康妇女的外周血，以及卵巢恶性肿瘤患者术后1周和1个月的外周血，采用微量基因组提取试剂盒提取血浆DNA，双链DNA高敏试剂盒和荧光仪测定血浆DNA含量。结果：卵巢恶性肿瘤患者血浆DNA含量[（25．33±17．69）μg·L^-1]明显高于正常者[（7．60±3．87）μg·L^-1]和良性肿瘤患者[（10．28士4．80）μg·L^-1]（P〈O．001），良性肿瘤患者的血浆DNA水平与正常者之间比较差异无显著性（P〉0．05）。恶性卵巢瘤I～Ⅱ期患者的血浆DNA含量[（15．83士5．30）μg·L^-1]明显高于正常对照组（P〈0．01），Ⅲ～Ⅳ期患者的血浆DNA含量[（30．83士20．04）μg·L^-1]高于Ⅰ～Ⅱ期（P=0．005）；有腹膜后淋巴结转移或远处转移者的血浆DNA含量[（35．43±21．08）μg·L^-1]较无转移者[（16．49士6．44）μg·L^-1]明显升高（P=0．006）；手术后1周，卵巢恶性肿瘤患者的血浆DNA含量[（20．88士12．14）μg·L^-1]与手术前比较无明显差别（P〉0．05），手术后1个月，卵巢恶性肿瘤患者的血浆DNA含量[（10．30士2．45）μg·L^-1]较手术前明显下降（P〈O．001），基本恢复到正常水平；高血浆DNA含量组的累积生存率明显低于低血浆DNA含量组（P=0．027）。以正常对照者血浆DNA水平的95％可信区间上限15．70μg·L^-1为临界值，其诊断的敏感性为63．30％，特异性为90．00％。结论：血浆DNA水平有可能成为辅助早期诊断卵巢恶性肿瘤、判断肿瘤侵袭转移情况和预测预后的指标之一。

Objective To determine the plasma DNA level of patients with ovarian cancer and evaluate its potential clinical value. Methods Blood samples were collected from 30 ovarian cancer patients before and after surgery, and from 20 patients with ovarian benign tumor and 20 healthy women. The plasma DNA wag extracted by commercial kit and detected by fluorescntmeter. Results The mean plasma DNA level in the cancer patients （25.33 μg·L^-1±17.69 25.33 μg·L^-1） was significantly higher than those in the benign tumor patients （10. 28μg·L^-1±4. 80 μg·L^-1） and normal control （7.60 μg·L^-1±3.87μg·L^-1） （P〈0. 001）. There was no significant difference between the benign and normal groups. The plasma DNA level of the patients in stage Ⅰ-Ⅱ （15.83 μg·L^-1±5.30μg·L^-1） was significantly higher than that in the normal control （P〈0. 01） and was significantly lower than that in stage Ⅲ- Ⅳ （30. 83μg·L^-1±20.04μg·L^-1） （p=0.005） . The plasma DNA level of patients with metastasis （35.43μg·L^-1±21.08μg·L^-1） was significantly higher than that of patents with no metastasis （16.49 μg·L^-1±6. 44 μg·L^-1） （P=0. 006） . The DNA level in the cancer patients one month after surgery （10.30±2.45 μg·L^-1） was much lower than before surgery （P〈0. 001）, near that in the normal control. The overall survival of the patients with high plasma DNA level was much shorter than that of the patients with low DNA level （P=0. 027）. When the cut-off for diagnosis of ovarian cancer was 15.70 μg·L^-1 , the sensitivity and specificity were 63.30% and 90.00%, respectively. Conclusion The plasma DNA level may have a potential use in early diagnosis and serve as a predict marker for metastasis potential and prognosis of ovarian cancer.