Induction of ovarian steroidogenesis as an additional potential risk factor for progression in premenopausal patients with hormone-receptor-positive breast cancer receiving tamoxifen as adjuvant therapy

Introduction. Patients with hormone-receptor-positive (HR+) breast cancer (BC) over 40 years old who take tamoxifen are not subject to mandatory castration. However this cohort of patients is not homogeneous.Aim. The present study is aimed at studying the features of ovarian steroidogenesis in perimenopausal breast cancer patients receiving adjuvant hormone therapy (HT) with tamoxifen.Materialy and methods. The study included 82 patients aged 42 to 53 years with GH+BC who received HT with tamoxifen 20 mg daily. Within 9 months from the start of HT in patients, the levels of estradiol and follicle-stimulating hormone in the peripheral blood were studied every 3 months.Results. In 66.7% of patients who received chemotherapy (CT), the development of amenorrhea was noted. Half of the patients in the HT-only group demonstrated amenorrhea. Oligomenorrhea was observed in 20.8% and 16.7% in each group, respectively. The incidence of amenorrhea in women treated with chemotherapy was higher (OR 2.02; 95% CI: 0.73-5.67), but the differences were not statistically significant (p = 0.1766). In the general cohort, in 15.7-16.8% of patients, the level of estradiol exceeded 251 pg / ml - the upper limit of the norm of the follicular phase of the menstrual cycle. Differences between groups in the incidence of estradiol levels > 251 pg/ml were statistically significant (p = 0.0293). 3.4-5.6% of patients in the total cohort (depending on the period of observation) had an estradiol level > 649 pg / ml, which corresponded to the highest ovulatory value.Conclusions. Against the background of HT with tamoxifen in some perimenopausal patients hyperestrogenism is observed which indicates the implementation of the effect of induction of ovarian steroidogenesis and can be considered as an additional potential risk factor for the progression of HR+BC. Amenorrhea after CT is not a reliable marker of ovarian suppression