Postoperative Adjuvant Combination Therapy with Doxorubicin and Noncytotoxic Suramin in Dogs with Appendicular Osteosarcoma

Abstract

Although conventional treatment of dogs with osteosarcoma (OSA) by amputation and chemotherapy results in reported survival times (STs) of 262–413 days, no major improvements in STs have occurred in the past 2 decades. Suramin is a polysulfonated napthylurea, which at noncytotoxic concentrations in vitro, increases tumor sensitivity to chemotherapy, including doxorubicin. The study authors evaluated the combination of noncytotoxic suramin and doxorubicin after amputation in dogs with OSA. The hypothesis was that treatment of dogs with appendicular OSA with amputation, adjuvant doxorubicin, and noncytotoxic suramin would be well tolerated and result in STs at least comparable to those of doxorubicin alone. Forty-seven dogs received 6.75 mg/kg of suramin IV followed by 30 mg/m2 of doxorubicin IV 4 hr later. Treatment was repeated q 2 wk for five doses. The median disease free time (DFI) was 203 days (range, 42–1,580+ days) and the median ST for all dogs was 369 days (range, 92–1,616+ days). There was no statistical difference in ST and DFI between greyhounds and nonngreyhounds. Adjuvant doxorubicin and noncytotoxic suramin was well tolerated in dogs with OSA following amputation. Additional studies are needed to determine if this combination treatment protocol provides additional clinical benefit compared with doxorubicin alone.