[Effects of etidronate disodium (EHDP) on urogenital malignancies with bone metastasis: a multicentered collaborative evaluation].

Clinical effects of EHDP on relief of bone pain, changes in bone lesions on X-ray and 99mTc-MDP scintigram and performance status were investigated in 19 patients with bone metastasis from urogenital cancers (4 renal cell cancers, 1 renal pelvic cancer, 4 bladder cancers and 10 prostatic cancers). EHDP was effective in relieving bone pain in prostatic cancer patients with osteoblastic lesions. Bone lesions on X-ray and 99mTc-MDP scintigram were slightly improved in prostatic cancer patients with osteoblastic lesions. Administration of EHDP did not improve the performance status. Changes in laboratory data such as serum alkaline phosphatase, serum calcium and urinary total hydroxy-proline following EHDP administration indicated inhibition of osteolytic activity with no effect on bone formation in the early period of treatment (in 4 weeks) and development of both osteolytic activity and bone formation in the later period (from 8 to 12 weeks). No marked side effects were observed. EHDP seems to be effective in relieving bone pain in prostatic cancer patients with osteoblastic bone metastasis. Moreover, some diphosphonate groups including EHDP are expected to be useful to the patients with malignant hypercalcemia.