Koga Tadashi, Tokunaga Eriko, Sumiyoshi Yasushi, Oki Eiji, Oda Shinya, Takahashi Ikuo, Kakeji Yoshihiro, Baba Hideo, Maehara Yoshihiko
Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
Hepatogastroenterology. 2008 May-Jun;55(84):1131-5.
BACKGROUND/AIMS: Detection of occult cancer cells in peripheral blood or bone marrow has recently received a great deal of attention regarding the prediction of postoperative recurrence of the cancer, and for novel strategies of adjuvant therapy. This study addresses the detection of circulating tumor cells in peripheral blood in patients with gastric cancer using Quantitative RT-PCR.
Common mRNA targets for RT-PCR for detection of small numbers of cancer cells in gastric cancer are CK18, CK19, CK20, and CEA. Ten milliliter of peripheral venous blood was taken from 14 healthy Japanese volunteers and 101 patients with gastric cancer. Samples were analyzed using real-time TaqMan technology and a Model 7700-sequence system. The group of gastric cancer patients included 69 individuals with curative disease on preoperative diagnosis and 32 individuals with a non-curative operation or recurrence of the disease.
The number of CK19 and CK20 mRNA copies was significantly increased in patients with a non-curative operation or recurrence of gastric cancer (CK19; p=0.0087, CK20; p=0.0022) compared with healthy volunteers. Cut-off levels of CK19 or CK20 copy numbers were determined by the maximum value of healthy volunteers. For CK19, there were 61 (88.4%) negative cases and 8 (11.6%) positive cases in 69 individuals with curative gastric cancer. There was a significant difference in tumor stages between CK19 positive and negative patients with curative disease on preoperative diagnosis. For CK20, there were 59 (85.5%) negative cases and 10 (15.5%) positive cases. There was no statistical difference between CK20 positive and negative cases for all clinicopathological factors. On postoperative day 14, there was a significant difference between positive and negative cases regarding tumor size, tumor stage, and lymph node metastasis for CK19, and tumor stage and lymph node metastasis for CK20. Five-year survival rates of patients with CK19 positive or negative cases were 50.0% or 79.0%, respectively (p=0.0347). While, for CK20, 5-year survival rates for positive cases was 51.9%, and for negative cases 78.9% (p=0.0490).
Micrometastases of gastric cancer can be detected in circulating peripheral blood using quantitative real-time RT-PCR. CK19 is a better marker than CK18, CK20 and CEA, and could be clinically useful to estimate prognosis or to make a postoperative strategy of adjuvant treatment.
背景/目的：外周血或骨髓中隐匿癌细胞的检测在癌症术后复发预测及辅助治疗新策略方面近来备受关注。本研究采用定量逆转录聚合酶链反应（Quantitative RT-PCR）检测胃癌患者外周血中的循环肿瘤细胞。
用于检测胃癌中少量癌细胞的逆转录聚合酶链反应（RT-PCR）常见信使核糖核酸（mRNA）靶点为细胞角蛋白18（CK18）、细胞角蛋白19（CK19）、细胞角蛋白20（CK20）和癌胚抗原（CEA）。采集了14名健康日本志愿者和101例胃癌患者的10毫升外周静脉血。样本采用实时TaqMan技术和7700序列系统进行分析。胃癌患者组包括术前诊断为根治性疾病的69例个体以及接受非根治性手术或疾病复发的32例个体。
与健康志愿者相比，接受非根治性手术或胃癌复发患者的CK19和CK20 mRNA拷贝数显著增加（CK19；p = 0.0087，CK20；p = 0.0022）。CK19或CK20拷贝数的截断水平由健康志愿者的最大值确定。对于CK19，69例根治性胃癌患者中有61例（88.4%）为阴性病例，8例（11.6%）为阳性病例。术前诊断为根治性疾病的CK19阳性和阴性患者的肿瘤分期存在显著差异。对于CK20，有59例（85.5%）阴性病例和10例（15.5%）阳性病例。所有临床病理因素的CK20阳性和阴性病例之间无统计学差异。术后第14天，CK19阳性和阴性病例在肿瘤大小、肿瘤分期和淋巴结转移方面存在显著差异，CK20在肿瘤分期和淋巴结转移方面存在显著差异。CK19阳性或阴性病例患者的5年生存率分别为50.0%或79.0%（p = 0.0347）。而对于CK20，阳性病例的5年生存率为51.9%，阴性病例为78.9%（p = 0.0490）。
采用定量实时逆转录聚合酶链反应可在外周循环血中检测到胃癌微转移。CK19是比CK18、CK20和CEA更好的标志物，在评估预后或制定术后辅助治疗策略方面可能具有临床应用价值。
