Clinical evaluation of a new tumour marker TAG 12 in breast cancer.

The aim of the present study was to evaluate the clinical value of the new tumour marker TAG 12 in sera from patients with breast cancer, patients with benign breast disease and normal controls. The results for TAG 12 were compared with those for CA 15-3 and MCA. The cut-off levels (95th percentile) determined for each test in the benign and control groups were 59 KU/l for TAG 12, 27 KU/l for CA 15-3 and 12 KU/l for MCA. The diagnostic sensitivity of the TAG 12 test was 0.30 (cut-off level 59 KU/l), 0.25 for CA 15-3 test (cut-off level 27 KU/l) and 0.15 for MCA test (cut-off level 12 KU/l) in detecting breast cancer. The combination of TAG 12, CA 15-3 and MCA reached the diagnostic sensitivity 0.35, specificity 0.90, efficiency 0.68, LR+ 3.5, and LR- 0.72 The correlation coefficient in breast cancer patients between TAG 12 and CA 15-3 was 0.99 and the correlation coefficient between TAG 12 and MCA was 0.95. In conclusion, the results indicate that TAG 12, CA 15-3 and MCA have only limited value in the diagnosis of breast cancer, but their role in monitoring and follow-up of breast cancer patients is a subject for further investigation.