Chemotherapeutic treatment of xenograft Spirocerca lupi-associated sarcoma in a murine model

To date, data are not available concerning the effectiveness of chemotherapy in the treatment of Spirocerca lupi-associated esophageal sarcomas. In the present study, we compared the effectiveness of 4 chemotherapeutic agents against S. lupi-associated osteosarcoma, using a xenograft murine model created in our lab. Samples of xenografted osteosarcoma were inoculated subcutaneously into 5 groups (n = 10 each) of 6-wk-old male and female NOD/SCID mice. Tumor-bearing mice were divided into treatment and control groups. The treatment groups were injected with either pegylated liposomal doxorubicin (6 mg/kg, intravenously, n = 9), doxorubicin (6 mg/kg, intravenously, n = 8), carboplatin (60 mg/kg, intraperitoneally, repeated twice at 1-wk intervals for a total of 2 doses, n = 9), or cisplatin (6 mg/kg, intraperitoneally, n = 8). The control group was injected with buffered saline (n = 9). Tumor size was determined by caliper measurements. Compared with the control group, the pegylated liposomal doxorubicin- and doxorubicin-treated groups, but not the carboplatin or cisplatin groups, showed significant inhibition of tumor growth. Our results indicate that doxorubicin-based drugs are effective against S. lupi-associated sarcomas in a mouse xenograft model. Because it is less toxic than doxorubicin, pegylated liposomal doxorubicin is likely the drug of choice for treatment of S. lupi-associated sarcomas. We suggest that combination of doxorubicin or its pegylated form with surgical excision will improve the prognosis of dogs with this disease.