Aim: Evaluation of pathological estimation results of therapeutic response of primary breast carcinoma to applied neoadjuvant therapy. Introduction: Breast carcinoma is heterogeneous disease, that could be classified into several molecular subtypes by using immunohistochemical analysis and in situ hybridization. Neoadjuvant therapy is applied in cases of locally advanced breast carcinoma and for tumor chemosensitivity evaluation, which is very significant for disease prognosis. Material and Methods: The research was conducted on 35 female patients, that were treated with radical mastectomy in 2017, after IV cycle of neoadjuvant therapy, in Clinical Centre of Montenegro. Before treatment, all patients underwent core biopsy (confirmed invasive breast carcinoma, molecular subtype determined).Pathohistological response of primary tumor to applied therapy was estimated as complete response (pCR), partial response (pPR) and no response (pNR). Results: Average age in examined group of patients was 59,25 years.In 68,58% of cases it was invasive ductal, in 17,14% invasive lobular and in 14,28% mixed invasive carcinoma. Representation of molecular subtypes was (without change in respect to the core biopsy): 34,28% Luminal A, 42,85% Luminal B Her2 negative, 5,71% Luminal B Her2 positive, 8,58% Her2 positive and 8,58% triple negative. In 6 patients (17,15%) pCR was obtained, in 21 (71,42%) pPR, and in 4 (11,43%) no response. In group of patients confirmed for pCR, it was Her2 positive or triple negative carcinoma. Conclusion: Applying of neoadjuvant therapy leads to tumor response to applied therapy. Most commonly it is partial response, while complete response most commonly occurs in Her2 positive or triple negative carcinomas.

Aim: To investigate concordance rate between the results of expression of steroid receptors, human epidermal growth factor 2 receptors (Her2) and determined molecular subtypes in surgical specimens (SS) and samples obtained by core biopsy (CB). Introduction: CB is widely accepted method in the initial diagnosis of breast cancer, but its reliability in determining the status of steroid and Her2 receptors, Ki67 index and molecular subtypes is still a matter of debate. Material and Methods: We analyzed 54 cases of invasive breast cancer, in which the expression of estrogen (ER), progesterone (PR) and Her2 receptors and Ki67 index were determined both in CB and SS. Concordance rate for ER, PR and Her2 receptors expression and molecular subtypes, between CB and SS, was calculated using k-test (p<0.001). Results: The average age of patients was 62. In SS, Luminal A subtype was most commonly diagnosed (48%), followed by: Luminal B Her2-(31%) and TNBC (13%), while Luminal B Her2 and Her2-enriched subtypes were represented by 4% each. Frequencies of molecular subtypes in CB were: Luminal A (41%), LuminalB Her2- (33%), TNBC (15%), Luminal B Her2 (7%), Her2-enriched (4%). Concordance rate for ER receptors was 93.8%(Kappa=0.936), for PR 77.5%(Kappa=0.773), for Her2 80.0%(Kappa=0.78) and for molecular subtypes 80.9%(Kappa=0.753). Conclusion: Statistical analysis showed very good agreement in terms of determined molecular subtypes and ER receptors expression and good agreement for the expression of PR and Her2 receptors. CB represents reliable method for determining the status of expression of steroid and Her2 receptors, as well as tumor molecular subtypes.