Objective—To determine toxic effects of streptozocin
given in combination with a diuresis protocol in dogs
and establish whether streptozocin is efficacious in
treatment of pancreatic islet cell tumors in dogs.
Procedure—Medical records were reviewed to
obtain information regarding signalment, tumor stage
and staging tests performed, number of streptozocin
treatments, adverse effects, results of biochemical
and hematologic monitoring during streptozocin treatment,
tumor dimensions, duration of normoglycemia,
and date of death, when applicable. Dogs were compared
with a historical control group of 15 dogs treated
surgically and medically.
Results—58 treatments were administered to the 17
dogs. Only 1 dog developed azotemia. Serum alanine
aminotransferase activity increased in some dogs but
decreased when treatment was discontinued.
Hematologic toxicoses were rare. Vomiting during
administration was uncommon but occasionally
severe. Two dogs developed diabetes mellitus after
receiving 5 doses. Median duration of normoglycemia
for 14 dogs with stage-II or -III insulinoma treated with
streptozocin was 163 days (95% confidence interval,
16 to 309 days), which was not significantly different
from that for the control dogs (90 days; 95% confidence
interval, 0 to 426 days). Two dogs had rapid resolution
of paraneoplastic peripheral neuropathy, and 2
others had measurable reductions in tumor size.
Conclusions and Clinical Relevance—Results
suggest that streptozocin can be administered safely
to dogs at a dosage of 500 mg/m2, IV, every 3
weeks when combined with a protocol for induction
of diuresis and may be efficacious in the treatment
of dogs with metastatic pancreatic islet cell tumors.
(J Am Vet Med Assoc 2002;221:811–818)