在转移前的实质肿瘤生长过程中已有血循癌细胞的出现 ,很少持续并发展成血源性转移 ,绝大多数在肿瘤切除后 2 4小时内消失。逆转录酶 -多聚酶链反应(RT- PCR)是检测血循中癌细胞的可靠方法。为了阐明 RT- PCR持续阳性与原发肿瘤的分期和转移之间的关系 ,取伦敦两家医院于 1997 The presence of circulating blood cancer cells during the growth of the metastatic tumor prior to metastasis rarely persists and develops into hematogenous metastases, with the vast majority disappearing 24 hours after tumor resection. Reverse transcriptase-polymerase chain reaction (RT-PCR) is a reliable method of detecting cancer cells in blood circulation. In order to elucidate the relationship between persistent RT-PCR and staging and metastasis of primary tumors, two London hospitals were recruited in 1997