Chemotherapy-induced estradiol reduction is associated with less relief of pre-chemotherapy anxiety in breast cancer patients.

Chemotherapy-induced apoptosis of mature ovarian follicles in breast cancer patients likely results in decreased circulating estradiol (E2), although this is rarely measured. Outside of cancer, sudden E2 reductions (e.g., post-childbirth) are associated with increased anxiety and depressive symptoms. About half of breast cancer patients undergoing chemotherapy report anxiety and depressive symptoms, which is a major reason for discontinuing or changing chemotherapy treatment. This study examined the relationship between E2 reductions and anxiety/depressive symptoms, during chemotherapy. As a secondary outcome, intolerance of uncertainty was also assessed. Blood samples and patient-reported questionnaires were collected from 77 breast cancer patients. Plasma E2 concentrations were quantified using ELISA. Chemotherapy-induced reductions in circulating E2 were associated with less relief from pre-chemotherapy anxiety symptoms and intolerance of uncertainty during chemotherapy, regardless of age and menopausal status. Conversely, participants whose E2 concentrations did not decrease experienced relief from pre-chemotherapy anxiety symptoms and intolerance of uncertainty during chemotherapy. Similar trends were observed for depressive symptoms. These findings suggest that monitoring circulating E2 levels may provide valuable mechanistical insights into patients' psychological responses during chemotherapy and could inform more personalized approaches to supportive care.