This was quantitative research in the form of prospective cohort observations at Dr. Moewardi Hospital between April 2021 and May 2022. This study observed changes in estradiol levels before and after adjuvant chemotherapy in breast cancer patients. The inclusion criteria were breast cancer patients who had undergone modified radical mastectomy or simple mastectomy, planned to undergo six cycles of chemotherapy, and had never received hormonal therapy or neoadjuvant chemotherapy. The exclusion criteria were comorbidities or conditions that could increase estradiol levels; patients lost to follow-up, namely, chemotherapy was not on schedule; incomplete chemotherapy; and death during chemotherapy.
Primary data collection included age, sex, and risk factors for breast cancer. Data on cancer included cancer stage, cell type, grade, subtype, and chemotherapy regimen. The estradiol levels were taken in the morning regarding the patient’s menopausal status, with normal values of 90 - 270 pg/mL using the DRG Estradiol ELISA, an immunoassay enzyme used for measuring the in vitro diagnostic quantity of estradiol in serum and plasma [6 ]. The estradiol levels were taken twice. The first was before the patient underwent the first cycle, and the second was 3 weeks after the patient went through the sixth cycle of chemotherapy.
Primary data collection included age, sex, and risk factors for breast cancer. Data on cancer included cancer stage, cell type, grade, subtype, and chemotherapy regimen. The estradiol levels were taken in the morning regarding the patient’s menopausal status, with normal values of 90 - 270 pg/mL using the DRG Estradiol ELISA, an immunoassay enzyme used for measuring the in vitro diagnostic quantity of estradiol in serum and plasma [6 ]. The estradiol levels were taken twice. The first was before the patient underwent the first cycle, and the second was 3 weeks after the patient went through the sixth cycle of chemotherapy.
