Monitoring different stages of breast cancer using tumour markers CA 15-3, CEA and TPA

The ability of the tumour markers Cancer Antigen 15-3 (CA 15-3), Carcinoembryonic Antigen (CEA), and Tissue Polypeptide Antigen (TPA) to signal progression in breast cancer patients was investigated in this study. Marker interpretation considered the analytical variation, intra-individual biological variation, and the rate of increase. Patient cohorts were as follows: (A) 90 stage II breast cancer patients who were monitored postoperatively, (B) 204 recurrent breast cancer patients who were monitored during first-line chemotherapy, and (C) 112 patients who were monitored during the time period after first-line chemotherapy. The sensitivity for progression was 44% (cohort A), 69% (cohort B), and 68% (cohort C) without any false progression signals. Marker lead-times exceeded 3 months in 20% (cohort A) and 27% (cohort C) of patients. Marker lead-times were 1-6 months among 33% of the patients receiving first-line chemotherapy (cohort B). Trials are necessary to determine whether tumour marker-guided therapy has any prognostic impact. The data suggest that tumour marker information may be used to stop ineffective treatments and reduce unnecessary adverse effects.