Clinical significance of circulating cancer cells in peripheral blood detected by reverse transcriptase-polymerase chain reaction in patients with breast cancer

Detection of breast cancer micrometastases based on specific genetic marker s may provide useful information to justify appropriate therapeutic strateg ies. We examined the presence of a carcinoembryonic antigen (CEA) messenger RNA(mRNA) in the peripheral blood of 32 patients with varying stages of br east cancers by means of the reverse transcriptase-polymerase chain reactio n (RT-PCR)assay prior to and after the curative operation. CEA mRNA were de tected in the peripheral blood samples from 12 (38%) out of 32 breast cance r patients prior to surgery. Among 12 CEA mRNA-positive patients prior to s urgery, 4 (33.3%) relapsed from breast cancer within 2 years after surgery. Moreover, CEA mRNA was detected in the peripheral blood samples obtained p rior to surgery in 3 out of 11 patients (27.2%) with a stage I disease. One out of three of these patients had a relapse in lung. There were four patt erns of CEA mRNA expression, (+, +), (+, -), (-, +), and (-, -) in the pre- and post-operative blood samples. In 12 CEA mRNA-positive patients submitt ed to surgical resection of the primary tumor, persistence of CEA mRNA expr ession was observed in five patients (+, +) within a month after surgical t reatment. Three out of these 5 patients (60%) relapsed from breast cancer w ithin 2 years after surgery. In 7 other patients (+, -), CEA mRNA expressio n was not detected within a month after tumor removal, and recurrence occur red in 1 out of the 7 patients (14%) within 2 years after surgery. In 19 pa tients, CEA mRNA expression was not detected in pre- or post-operative bloo d samples (-, -). There was a patient whose blood sample was negative for C EA mRNA before the operation, but changed to show a positive result after s urgery (-, +). No recurrence was found in 20 of CEA mRNA-negative patients prior to surgery (-, +), (-, -). This study suggested that the presence of CEA mRNA expression in preoperative peripheral blood sample represent the p rogression of the disease, especially the risk of hematogenous metastasis i n the patients in spite of their clinical stage, and the presence of CEA mR NA in the postoperative blood sample may represent the evidence of a residu al disease. Thus consideration might be given for adding combined multi-mod al therapy. CEA mRNA; RT-PCR; peripheral blood; breast cancer (C) 2001 Toho ku University Medical Press.