Tamoxifen flare hypercalcemia: an additional support for gallium nitrate usage.

In 12 of 93 hypercalcemic patients with metastatic advanced breast cancer treated with tamoxifen the most common life-threatening metabolic complication of flare hypercalcemia developed. All the hypercalcemic patients had osteolytic or mixed lytic and blastic bone metastases. In patients with advanced breast cancer, hypercalcemia develops within the first few weeks of initiation of tamoxifen therapy.