EVALUATION OF CA-15-3 TUMOR-MARKER IN THE DIAGNOSIS OF BREAST-CANCER - A PILOT-STUDY

Single determinations of serum CA 15-3 levels were performed by sandwich ch enzyme immunoassay in 160 women: 77 patients with nonmalignant breast tumors (64 had fibrocystic disease, 11 had fibroadenoma, 2 had intraductal papilloma) and 83 patients with primary breast canter prior to any treatment; the cut-off limit was established at 30 U/ml. The overall diagnostic sensitivity and specificity of the CA 15-3 test was 19.3% and 94.8%, respectively. The positive and negative predictive values were 80.0%, and 52.1%. The mean CA 15-3 value was significantly lower in patients with benign breast tumors as compared with the breast cancer group: 16.8 +/- 8.2 vs. 23.9 +/- 20.9 U/ml (p < 0.01) as well as the percentage of positive results of the test: 5.2% vs. 19.3% (p < 0.02). Serum CA 15-3 level in breast cancer patients correlated with: (If clinical stage: a higher percentage of positive results was observed in patients with more advanced cancer: Stage I - 0%, Stage II - 10.6%, Stage III - 29.6%, and Stage IV - 100.0% according to UICC classification; the comparison of breast cancer patients with early stage of disease (I + II) and those with more advanced cancer (III + IV) revealed statistically significant (p < 0.01) difference in the mean serum CA 15.3 value (19.7 +/- 12.8 vs. 31.5 +/- 29.2 U/ml) as well as in the percentage of positive results (9.4% vs.36.7% p < 0.01); (2) the histological grading according to BLOOM and RICHARDSON [4]: 5.41% of positivity was observed in low and intermediate grade cancers (I + II) vs. 66.7% in grade III (p < 0.001). In conclusion, our data confirmed that the diagnostic sensitivity of CA 15-3 assay was Low thus not suitable for diagnosis of early breast cancer and for differentiation between benign and malignant breast diseases. The CA 15-3 was directly related to the stage of breast cancer and the degree of malignancy which are highly correlated to prognosis.