THE ROLE OF Ca 15-3 IN THE DIAGNOSIS AND SCREENING OF BREAST CANCER

Tumor markers are specific substances secreted by healthy cells of the body as an immune response to the presence of malignant cells. Determination of the concentration of the tumor marker Ca 15-3 in serum is used to monitor breast cancer, i.e. the effect of the applied anticancer therapy. The increase or decrease in the concentration of the marker Ca 15-3 is correlated with the progression or regression of the disease. Carcinoma mammae or breast cancer occurs when abnormal cells begin to grow and multiply in the tissue, creating a benign or malignant tumor mass. The most common risk factors for the occurrence of breast cancer are hereditary gene mutations of the tumor suppressor genes BRCA1, creates tumors that do not grow under the influence of estrogen hormones, or BRCA2, creates tumors that need estrogen hormones for their growth. Men can also get breast cancer, but less often in about 1% of cases. The most common type of cancer is ductal carcinoma of the epithelial ductal cells, in the glandular tissue, lobular carcinoma, and less commonly lymphoma and sarcoma. Breast cancer develops in 4 stages, of which in the second stage it metastasizes to the other breast, in the third to the lymph nodes and in the fourth stage it metastasizes to more distant organs. It is most often treated with chemotherapy, hormone therapy or complete removal of the breast (mastectomy). The aim of the research and determination of the level of the tumor marker Ca 15-3 was to establish a suspected diagnosis of Carcinoma mammae, which with further testing and investigations will determine a final diagnosis. The aim was also to confirm the success of the treatment with anticancer drug therapy. For this purpose, patients aged 30-60 years were divided into 3 groups: a control group with a normal level of Ca 15-3 in serum, a group of patients with a confirmed diagnosis of Carcinoma mammae, and a group of patients treated with therapy to reduce the level of Ca 15-3, Tamoksifen. The determination of the level of Ca 15-3 concentration was with an ELISA test, which is an enzyme-linked immunosorbent sandwich method, carried out on an immunoanalyzer TOSON in the biochemical laboratory at the J.Z.U. Clinical Hospital - Stip. The results obtained from the research show that patients diagnosed with Carcinoma mammae have significantly increased results for the concentration of Ca 15-3 compared to patients from the control group whose results are within the normal reference values for Ca 15-3. The group of patients treated with therapy to reduce the level of Ca 125 in the blood, Tamoxifen, have evidently reduced results for the level of Ca 15-3. These results show the visible effect of the treatment with Tamoxifen in reducing the concentration of Ca 15-3, i.e. the successful treatment of Carcinoma mammae. Breast cancer cells need female hormones estrogen or progesterone for their growth and bind them to their specific receptors on their surface, cytoplasm or nucleus, which are specific for these hormones, i.e. they can be (ER) estrogen, (PR) progesterone and (HER2) human epidermal growth factor 2. The drug Tamoxifen is an estrogen blocker that blocks the binding of estrogen to the specific estrogen receptor of breast cancer tumor cells and prevents them from using it for their growth by preventing transcription of estrogen-dependent genes. The increased concentration of the carbohydrate tumor marker Ca 15-3 means that there is malignancy and a poor response to the applied therapy, while a decrease in its concentration means a favorable response to the applied therapy. From the research conducted on the effect of treatment with anticancer hormonal therapy with estrogen blockers, Tamoksifen, it was concluded that the negative effect caused by the influence of the presence of breast cancer is removed because it prevents the binding of estrogen hormones to their receptors on tumor cells, and thus prevents tumor growth.