Hypouricemia and cancer. A study of the mechanisms of renal urate wasting in two cases.

Two cases of hypouricemia in association with malignant diseases are presented. One patient had metastatic breast cancer and the other an undifferentiated retroperitoneal sarcoma of the childhood. Uric acid renal handling was studied with the pyrazinamide and benzbromarone tests. Both patients had reduced postsecretory reabsorption of uric acid. The increase of serum uric acid levels in both patients, after a partial response to chemotherapy, indicates the possible paraneoplastic origin of hypouricemia. Our results are discussed and compared with other reports in the literature.