Initial and following seram prolactin levels were measured in accordance with other tumor markers (CEA, CA 15-3,LAP) in 87 breast cancer patients who applied to the Oncology Department, Çukurova University Medical School. Nineteen (26 %) of the 73 patients with inactive non-metastatic tumor and 5 (35 %) of the 14 patients with metastatic disease presented with high levels of serum prolactin (55.52±19.4 ng/ml, 33.96±19.34 ng/ml). On further measurements in the 14 (19 %) patients with stable disease and in all of the patients with metastatic disease, serum prolactin levels decreased significantly (p=0.0002, p=0.021). On the other hand, CA 15-3 level was found to be increased in 73 % and LAP score was high in 96 % of the patients with metastatic disease. This preliminary study has forced us to go on to search more information in this field.

Keywords: Breast cancer, prolactin, tumor markers