The disodium salt of the synthetic bisphosphonate pamidronate. Although its mechanism of action is not completely understood, pamidronate appears to adsorb to calcium phosphate crystals in bone, blocking their dissolution by inhibiting osteoclast-mediated bone resorption. This agent does not inhibit bone mineralization and formation. Check foractive clinical trials using this agent. or A type of lung cancer that begins in the upper part of a lung and spreads to nearby tissues such as the ribs and vertebrae. Most Pancoast tumors are non-small cell cancers. Also called pulmonary sulcus tumor.