Skeletal involvement is a frequent and troublesome complication affecting many patients with neoplastic disease, especially multiple myeloma and cancer of the breast, lung, and prostate. This involve- ment can finally lead to local bone destruction with resulting frac- tures, local bone neoformation, or hypercalcemia. The latter com- plicates the clinical course of 10%-20% of the patients with non-smaIl-cell lung cancer and mammary tumors. Both knowledge of the pathophysiologic mechanisms and treatment of this skeletal involvement have progressed substantially in the last years. One of the very recent therapeutic advances has been the finding that bis- phosphonates, a family of compounds characterized by a P-C-P bond, are effective in alleviating some of these conditions. This volume represents the proceedings of a workshop held on December 4, 1987, in Lucerne, Switzerland, devoted to the use of bisphosphonates in tumoral bone disease. This educational work- shop was organized by the Swiss Group for Clinical Cancer Research (SAKK) to foster international scientific exchange and to clarify experimental and clinical problems in the therapeutic appli- cation of bisphosphonates. Experts from various countries were invited to present and discuss their experimental findings and their preliminary clinical results. This volume summarizes the invited contributions, which will be of major interest to clinical oncolo- gists, surgeons, internists, endocrinologists, and pathologists con- fronted with bone destruction in neoplastic disease. We acknowl- edge gratefully the support of Boehringer Mannheim (Schweiz) AG, Rotkreuz.