Detection of free-circulating tumor-associated DNA in plasma of colorectal cancer patients and its association with prognosis
Detection of free-circulating tumor-associated DNA in plasma of colorectal cancer patients and its association with prognosis
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DOI：
10.1002/ijc.10526
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发表时间：
2002-08-10
影响因子：
6.4
通讯作者：
Laurent-Puig, P
中科院分区：
文献类型：
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作者：
Lecomte, T;Berger, A;Laurent-Puig, P
肿瘤细胞以特定的基因改变为特征。当在包括血浆在内的体液中发现这种基因变化时，无论是否存在可检测到的肿瘤细胞，它都表明存在自由循环的肿瘤相关DNA。我们研究的目的是评估结直肠癌患者血浆中自由循环肿瘤相关DNA的预后价值。我们工作的第一步是找到肿瘤中常见的基因变化，随后将用于血浆DNA筛查。我们采用突变等位基因特异性扩增(MASA)方法和甲基化特异性聚合酶链式反应(MSP)方法对KRAS2基因第12、13密码子突变和p16基因高甲基化进行了研究。选择出现任何一种改变的肿瘤患者进行血浆筛查；对58例肿瘤进行KRAS2突变分析和p16基因启动子甲基化测试。对血浆中有无自由循环肿瘤相关DNA改变的患者的存活率和复发率进行了评估。在分析的58个肿瘤中，39个(67%)显示出研究中的一个或两个基因改变。22例(38%)在KRAS2发生突变，其中10例(45%)检测到相同的突变。31例(53%)p16基因启动子区高甲基化，其中21例(68%)血浆中也可检测到p16基因启动子甲基化。在39名肿瘤DNA发生其中一种或另一种变化的患者中，37人至少有一次可靠的血浆检测。在37例患者中，有26例(70%)在血浆中检测到自由循环的肿瘤相关DNA。在血浆中检测到自由循环肿瘤相关DNA的组和在血浆中未检测到自由循环肿瘤相关DNA的组的2年总生存率分别为48%和100%(p<；0.03)。在这37名患者中，有25名患者患有I、II或III期疾病。在这组患者中，在血浆中检测到自由循环肿瘤相关DNA的17名患者的两年无复发生存率为66%，而在血浆中未检测到自由循环肿瘤相关DNA的8名患者的两年无复发生存率为100%(p=0.044)。血浆中自由循环肿瘤相关DNA的存在似乎是结直肠癌患者的一个相关的预后标志物，并可用于识别高复发风险的患者。(C)2002年Wiley-Liss，Inc.
Tumor cells are characterized by specific genetic alterations. When such genetic alterations are identified in body fluid including plasma, regardless of the presence of detectable tumor cells, it shows the existence of free-circulating tumor-associated DNA. The objective of our study was to assess the prognostic value of free-circulating tumor-associated DNA in colorectal cancer patients' plasma. The first step of our work was to find common genetic alterations in tumors that would subsequently be used for plasma DNA screening. We focused on KRAS2 mutations in codons 12 and 13 by the mutant allele-specific amplification (MASA) method and p 16 hypermethylation by the methylation-specific polymerase chain reaction (MSP) method. Patients with a tumor presenting either alteration were selected for plasma screening; 58 tumors were analyzed for KRAS2 mutations and tested for p16 gene promoter methylation. Survival and recurrence rates were assessed in patients with and without free-circulating tumor-associated DNA alterations in plasma. Of the 58 tumors analyzed, 39 (67%) demonstrated either one or both of the studied genetic alterations. Twenty-two (38%) were mutated at KRAS2, and an identical alteration was detected in 10 (45%) of the 22 corresponding plasma samples. Thirty-one (53%) had p16 gene promoter hypermethylation that could also be detected in the plasma in 21 cases (68%). Among the 39 patients who had one or the other alteration in tumor DNA, 37 had at least one reliable plasma test. In 26 (70%) of the 37 patients, free-circulating tumor-associated DNA was detected in plasma. The 2-year overall survival rate was 48% in the group where free-circulating tumor-associated DNA was detected in plasma and 100% in the one where free-circulating tumor-associated DNA was not detected in plasma (p < 0.03). Among these 37 patients, 25 patients had a stage I, II or III disease. In this subgroup of patients, the 2-year recurrence-free survival rate for the 17 patients with free-circulating tumor-associated DNA detected in plasma was 66%, compared to 100% for the 8 patients without free-circulating tumor-associated DNA detected in plasma (p = 0.044). The presence of free-circulating tumor-associated DNA in plasma seems to be a relevant prognostic marker for patients with colorectal cancer and may be used to identify patients with a high risk of recurrence. (C) 2002 Wiley-Liss, Inc.