血浆循环游离DNA含量及完整性在乳腺癌中的临床价值

Clinical Value of Plasma Circulating Cell-free DNA Content and Integrity in Breast Cancer

目的探讨外周血中循环游离DNA(cf-DNA)含量和完整性在乳腺癌辅助诊断中的临床价值。方法收集2020年9月-2021年7月于我院就诊的56例乳腺癌患者血液样本设为病例组和体检中心20名健康体检健康人血样设为对照组。采用实时荧光定量PCR检测血液样本中cf-DNA含量和完整性,以长、短片段(241、100 bp)扩增产物比值作为cf-DNA完整性指标,并结合其临床病理特性进行分析。应用ROC曲线分析cf-DNA含量和完整性对乳腺癌辅助诊断的敏感度与特异度。应用Fisher检验分析乳腺癌患者临床病理参数与cf-DNA完整性的关系。结果病例组长、短片段血浆cf-DNA含量高于对照组,差异有统计学意义(P<0.05);病例组血浆cf-DNA完整性水平高于对照组,但差异无统计学意义(P>0.05);ROC曲线分析显示,长、短片段含量及完整性的曲线下面积分别是0.79、0.99、0.59,敏感度分别是70.00%、100.00%、44.46%,特异度分别是90.00%、95.00%、85.00%。构建成β-actin及长、短片段质粒标准品的扩增曲线,β-actin标准曲线的线性决定系数(R2)=0.9583,扩增效率达93.40%;短片段标准曲线的线性决定系数R2=0.8745,扩增效率达91.70%;长片段标准曲线的线性决定系数R2=0.9695,扩增效率达99.30%。无淋巴结转移乳腺癌患者血浆cf-DNA完整性低于有淋巴结转移的乳腺癌患者,差异有统计学意义(P<0.05)。结论血浆cf-DNA含量和完整性可以作为乳腺癌辅助诊断的潜在生物学指标,且cf-DNA完整性中可提高乳腺癌患者的诊断率。同时,淋巴结转移与cf-DNA完整性相关,可以检测其完整性以区分淋巴结是否转移。

Objective To investigate the clinical value of circulating-free cell DNA(cf-DNA)content and integrity in the diagnosis of breast cancer.Methods From September 2020 to July 2021,56 blood samples of breast cancer patients in our hospital were collected as patient group and 20 blood samples of healthy people in physical examination center as normal group.The content and integrity of cf-DNA in blood samples were detected by real-time fluorescence quantitative PCR.The ratio of amplification products of long and short fragments(241 and 100 bp)was used as an index of cf-DNA integrity,and its clinicopathological characteristics were analyzed.ROC curve was used to analyze the sensitivity and specificity of cf-DNA content and integrity in the diagnosis of breast cancer.Fisher test was used to analyze the relationship between clinicopathological parameters and cf-DNA integrity in breast cancer patients.Results The plasma cf-DNA content of long and short segments in the patient group was higher than that in the normal group,and the difference was statistically significant(P<0.05).The plasma cf-DNA integrity level in the patient group was higher than that in the normal group,but the difference was not statistically significant(P>0.05).ROC curve analysis showed that the area under the curve of long and short segment content and integrity was 0.79,0.99 and 0.59,respectively,the sensitivity was 70.00%,100.00%and 44.46%,respectively,and the specificity was 90.00%,95.00%and 85.00%,respectively.The amplification curve ofβ-actin,long and short fragment plasmid standard was constructed.The linear determination coefficient(R2)ofβ-actin standard curve was 0.9583,and the amplification efficiency was 93.40%;the linear coefficient of determination(R2)of the standard curve was 0.8745,and the amplification efficiency was 91.70%;the linear determination coefficient of the long fragment standard curve was R2=0.9695,and the amplification efficiency was 99.30%.The plasma cf-DNA integrity of breast cancer patients without lymph node metastasis was lower than that of breast cancer patients with lymph node metastasis,and the difference was statistically significant(P<0.05).Conclusion Plasma cf-DNA content and integrity can be used as potential biological indicators for auxiliary diagnosis of breast cancer,and cf-DNA integrity can improve the diagnosis rate of breast cancer patients.At the same time,lymph node metastasis is related to cf-DNA integrity,and its integrity can be detected to distinguish lymph node metastasis.