Because of the high incidence and mortality rates of breast cancer, it is important to investigate markers that can help in the early diagnosis and monitoring of carcinomas. New parameters for monitoring breast cancer that are being investigated are NLR, SII and PLR. NLR is the ratio of neutrophils to lymphocytes. It can be calculated as the ratio of the absolute number of neutrophils and lymphocytes or as the ratio of the percentage of neutrophils and lymphocytes. PLR is the ratio of platelet to lymphocyte count. The systemic immune-inflammatory index (SII) is determined based on NLR and platelet count. It is calculated as the product of NLR and platelet count. The aim of this study was to examine the association between new predictive markers and different tumor characteristics in patients prior to chemotherapy. Retrospective collection of data obtained from patient findings was used as a method. The period of collected data is from 2015 to 2021. Data collected during this period are age of patients, number of neutrophils, lymphocytes, platelets and leukocytes and molecular subtype of breast cancer, tumor stage, lymph node status, histological grade, vascular invasion status, estrogen and progesterone receptor status, HER-2 status and the percentage of Ki-67. The established limit values for the stated parameters were: NLR 2.13, PLR 88.23 and SII 547. Statistically significant P-value was obtained for PLR and SII and tumor stage, while for other parameters no statistically significant P-value was determined. A Kaplan-Meier overall survival curve was performed for all three hematological parameters. Out of a total of 90 patients, 78 were censored over a period of 60 months. All three parameters followed a similar trend in overall survival. PLR did not show a statistically significant association with any of the observed physico-pathological factors. The obtained data showed that in our case the increased SII value was associated with a lower tumor stage as well as the NLR value. The results obtained in this thesis differ from the results in the observed research papers. The difference in the results can be explained by the small number of patients and the large heterogeneity of the observed group.