Aim. In this article, we analyzed the age-related features of molecular- biological subtypes in 499 patients with invasive breast cancer. Materials and research methods. All cases were divided into 5 molecular- biological subtypes based on immunohistochemical studies of hormone receptors, Her2, Ki-67. Luminal (A and B) with the expression of estrogen and/or progesterone receptors (ER+/PR+), accounting for about 50-80% of all breast cancer cases and potentially sensitive, especially luminal A, to hormone therapy. Research results. The analysis showed that in our study the proportion of the Luminal A subtype was lower than the generally accepted values of 37.4% of all studied breast cancer cases. In the group of women under 40 years of age (with preserved menstrual-ovarian function), cases of Luminal A subtype were significantly less common (9.03%) compared to the groups of 41-50 years (p<0.006), 51-60 years (p<0.001), and over 60 (p<0.001). There was also a decrease in the proportion of Luminal A subtype among patients older than 60 years (p=0.0064). No significant differences were found between the groups 41-50 and over 60 years of age (p=0.1868).