Two menopausal patients with metastatic breast cancer and osteolytic bone metastases were treated with diethylstilbestrol in oral doses. In one patient, hypercalcemia developed within 48 hours of treatment with a total dose of 10.0 mg of diethylstilbestrol, and in the second patient hypercalcemia developed within 24 hours of therapy with a single 5.0-mg oral dose.
Swaroop S, Krant MJ. Rapid Estrogen-Induced Hypercalcemia. JAMA. 1973;223(8):913-914. doi:10.1001/jama.1973.03220080043012