Abstract
Aim. The aim of this study is to evaluate the relationship between the immunohistochemical score of cell proliferation index Ki-67 and steroid receptor in patients with a pathohistological diagnosis of breast cancer. The impact of neoadjuvant therapy on biological markers in breast cancer remains controversial.
Methods. All patients with invasive breast cancer, as the primary and only malignancy, who underwent surgical and neoadjuvant therapy at the Institute of Oncology and Radiology of the Republic of Serbia (IORS) between 2017 and 2019 were included in the retrospective study. The expression level of Ki-67 and steroid receptors was detected by immunohistochemical analysis. Data were collected in an Excel database and analysed in the statistical softwer SPSS program version 25. For statistical data processing Chi-squared test, Kruskal-Wallis test and Mann-Whitney U test were used. For all statistical analysis, a p <0,05 was considered statistically significant and a p≤0.001 was considered highly statistically significant.
Results. The study included 190 patients with invasive breast cancer. The mean age of all patients at diagnosis was 57,2 ± 11,8 years. Among the patients, 64.2% are postmenopausal, 33.7% perimenopausal and 2.1% menopausal. There is a significant inverse correlation between the value of Ki-67 and the expression of steroid receptors.
Conclusion. The results demonstrated that the patients with higher values of the cell proliferative index Ki-67 are associated with lower values of estrogen receptors (ER) and progesterone receptors (PR). Different age categories are not correlated with Ki-67 expression.