Wharton R Q, Jonas S K, Glover C, Khan Z A, Klokouzas A, Quinn H, Henry M, Allen-Mersh T G
Department of Gastrointestinal Surgery, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom.
Clin Cancer Res. 1999 Dec;5(12):4158-63.
The objectives of this study were to assess whether the use of two reverse transcription-PCR (RT-PCR) cDNA assays and multiple blood sampling increased circulating tumor cell detection in colorectal cancer patients. Systemic blood was sampled three times at 1-min intervals in 100 colorectal cancer patients (50 primary tumors only and 50 liver metastases), and in 70 control patients without known cancer. After removal of the erythrocytes, samples were subjected to separate RT-PCR reactions using specific primers for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20). Statistical analysis was performed by the two-sample binomial test and the one-sided McNemar test. There were significant increases in circulating tumor cell positivity when CEA and CK20 assays were used together as compared with either CEA or CK20 assay used alone. There were also significant increases in circulating tumor cell positivity for either CEA or CK20 assay used alone when the results from two blood samples were compared with the results from one sample. Circulating colorectal cancer cell positivity rose from 48% (CEA) and 34% (CK20) with one assay of one sample to 74% when both assays of three samples were used to identify circulating tumor cells. Three non-cancer control patients (4.3%) were positive for either CEA (two patients) or CK20 (one patient). Tumor cells were identified more frequently in the circulation of colorectal cancer patients than had been suggested previously. RT-PCR-based studies of the clinical significance of circulating cancer cells in colorectal cancer should involve multiple blood samples with identification of multiple tumor-related cDNA products.
本研究的目的是评估使用两种逆转录聚合酶链反应（RT-PCR）cDNA检测方法及多次采血是否能提高结直肠癌患者循环肿瘤细胞的检测率。对100例结直肠癌患者（50例仅为原发性肿瘤，50例为肝转移）和70例无已知癌症的对照患者，每隔1分钟采集一次外周血，共采集三次。去除红细胞后，使用针对癌胚抗原（CEA）和细胞角蛋白20（CK20）的特异性引物对样本进行单独的RT-PCR反应。采用双样本二项式检验和单侧McNemar检验进行统计分析。与单独使用CEA或CK20检测方法相比，联合使用CEA和CK20检测方法时，循环肿瘤细胞阳性率显著增加。当将两份血样的结果与一份血样的结果进行比较时，单独使用CEA或CK20检测方法时，循环肿瘤细胞阳性率也显著增加。使用三份血样的两种检测方法来识别循环肿瘤细胞时，循环结直肠癌细胞阳性率从一份血样一次检测时的48%（CEA）和34%（CK20）升至74%。三名非癌症对照患者（4.3%）CEA（两名患者）或CK20（一名患者）呈阳性。在结直肠癌患者的循环系统中检测到肿瘤细胞的频率比之前报道的更高。基于RT-PCR对结直肠癌循环癌细胞临床意义的研究应涉及采集多份血样并识别多种肿瘤相关cDNA产物。
