Neoplastic disorders may be complicated by
acute renal failure (ARF). Different
tumors may cause ARF: solid
tumors involving the kidney, solid
tumors not of hematological origin and not primarily involving the kidney or, more frequently, rapidly developing hematological
tumors. The pathogenesis of ARF is different depending on the type of
cancer, but the most frequent clinical feature is the acute
tumor lysis syndrome, characterized by
hyperuricemia,
hyperphosphatemia,
hyperkalemia,
hypocalcemia and acute, frequently oliguric, ARF. The presence of a neoplastic disorder and associated acute illness may sometimes lead to the presence of immunodysfunction, septic complications and multiple organ dysfunction. In these settings patients develop systemic
inflammation and diffuse endothelial damage, related to different mediators. Among these substances, in
cancer patients, high circulating levels of
uric acid are a common finding.
Hyperuricemia is caused by the increase of
purine metabolism, which is result of the increased cellular turnover or the aggressive
cancer chemotherapy regimens that worsen cell lysis and release of
purine metabolites. Even if
hyperuricemia is not the first insult to the kidney, its development might represent a concomitant factor aggravating other previous or simultaneous insults. The most efficient
therapy for lowering
uric acid is
rasburicase, a recombinant form of
urate oxidase, a nonhuman
proteolytic enzyme that oxidizes
uric acid to
allantoin. It is efficacious in reducing serum
uric acid levels with associated diuresis more effectively and much faster than
allopurinol, and to correct renal dysfunction more rapidly than
allopurinol.