CLINICAL-SIGNIFICANCE OF MOLECULAR-DETECTION OF CARCINOMA-CELLS IN LYMPH-NODES AND PERIPHERAL-BLOOD BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION IN PATIENTS WITH GASTROINTESTINAL OR BREAST CARCINOMAS

Purpose: This study evaluates the clinical significance of detection o f carcinoembryogenic antigen (CEA) mRNA in the dissected lymph nodes a nd peripheral blood samples of patients with gastrointestinal or breas t carcinomas. Patients and Methods: A total of 406 lymph nodes obtaine d from 65 patients were analyzed by both histologic and molecular exam ination of CEA-specific reverse transcriptase polymerase chain reactio n (RT-PCR). Peripheral blood samples from another 102 patients were al so analyzed by CEA-specific RT-PCR. Patients were followed up prospect ively for 24 +/- 12 months. Results: Of 406 lymph nodes, the positive detection rate increased from 20% by histologic examination to 60% by RT-PCR examination. The recurrence rate was 40% in 15 cases showing po sitive results in both examinations, 14% in 29 cases showing histologi cally negative bur RT-PCR positive results, and none in 21 cases showi ng negative results in both examinations. The positive detection rate for CEA mRNA in peripheral blood samples increased with advancing stag e of disease. With respect to 62 curatively operated cases, CEA mRNA w as detected in 12 cases. Four of these 12 cases developed metastatic d isease after surgery whereas none of 50 cases negative by RT-PCR devel oped metastasis. Conclusion: It has been shown that RT-PCR is a powerf ul tool to detect CEA mRNA in the lymph nodes or the peripheral blood. This is potentially very useful to determine high-risk patients for m etastasis. Serial analysis is warranted to assess the long-term signif icance of this method and its therapeutic and prognostic implications. (C) 1998 by American Society of Clinical Oncology.