RESPONSE TO CHEMOTHERAPY IN BREAST CANCER PATIENTS MAY DEPEND NOT ONLY ON TUMOR BIOLOGICAL SUBTYPE, BUT ALSO ON PATIENT'S HORMONAL STATUS
Breast cancer (BC) is the most striking example of a tumor whose hormonal profile, in addition to the extension and stage of the disease, provides important information about its aggressiveness. The purpose of the study was to measure blood levels of steroid hormones and pituitary hormones in patients with different biological subtypes of BC depending on their response to neoadjuvant chemotherapy. Levels of prolactin, estradiol, progesterone, testosterone, LH and FSH were measured by standard RIA in the blood serum of patients with luminal A and B subtypes and with triple-negative BC (TNBC) before and after neoadjuvant chemotherapy. The effectiveness of neoadjuvant chemotherapy for BC depended on the hormonal profile in patients with both luminal and triple-negative tumor subtypes. The response to chemotherapy in BC patients could be associated with both a decrease in the antitumor resistance of the body and the ability to respond to the stimulating effect of pituitary hormones, in particular LH, with the synthesis of progesterone and testosterone. The study revealed the prognostic nature of some of the studied hormones, in particular cortisol, progesterone and LH, reflecting the effectiveness of the antitumor treatment regimen. An examination of the hormonal status of BC patients is required at every stage of the treatment regardless of the initial biological subtype of the tumor, with possible correction of treatment regimens.