Symptomatic metastasis prediction with serial measurements of CA 15.3 in primary breast cancer patients

CA 15.3 is elevated in most patients with distant metastatic breast cancer who had prognostic information. The present study was performed to estimate predictive ability of CA 15.3 in assessment of symptomatic metastasis in patients with breast cancer. During five years, 159 primary breast cancer patients were evaluated. A total of 2226 determination of serum CA 15.3 (14 per patient) were performed. We performed contemporary clinical examinations with CA 15.3 measurements at the time of diagnosis, end of chemotherapy, every three months in the first two years and every six months in the second two years of follow-up period. Imaging studies were performed if clinical or laboratory examinations (abnormal serum levels of CA 15.3) suspected symptomatic metastasis. Metastasis in participants was confirmed by imaging study in symptomatic patients. There was no significant increase in CA 15.3 tumor markers during chemotherapy (P = 0.08). There was a significant relationship between CA 15.3 positive results and metastasis situation (P = 0.00). Mean of maximum CA 15.3 level in metastatic patients (52.72 ± 27.09) was significantly higher than non-metastatic patients (27.58 ± 13.46; P = 0.00). CA 15.3 abnormality (OR, 1.07; 95% CI: 1.04-1.11; P value, 0.01) and abnormal lymph nodes remained as predictor of metastasis (OR: 1.16; 95% CI: 1.05-1.28; P value < 0.0001). CA 15.3 is one of the predicting factors for symptomatic metastasis.