[The effectiveness of CDDP in metastatic adenocarcinoma with unknown origin]

A 28-year-old man with inoperable metastatic adenocarcinoma in the retroperitoneum was referred to our hospital for a further evaluation for its origin. The tumor was measured 80 x 107 mm by abd. U.S. and showed papillary adenocarcinoma, histologically. Chemotherapy with intravenous administration of CDDP at the dose of 80 mg/m2 for 6 times at 2-3 week intervals was started, and CDDP concentration of binding-form and free-form in serum and urine were measured in time course. The tumor has reduced for 29 weeks after the discontinuance of CDDP. Free-CDDP, which was thought to have an anticancerous effect, immediately went up high levels in serum and rapidly excreted to urine, while total-CDDP in serum remained in high concentration for more than 10 weeks. Thus it was suggested that anticancerous effect of CDDP could not be contributed only to free-CDDP and the mechanism of CDDP will be clarified by the elucidation of metabolism of both free and total CDDP, especially in the tumor tissue.