SURGERY AND DOXORUBICIN IN DOGS WITH HEMANGIOSARCOMA

Forty-six dogs with histologically confirmed hemangiosarcoma of variou s locations other than skin were used in a prospective study to determ ine the efficacy of adjuvant doxorubicin (30 mg/m(2) IV q 3 weeks for 5 treatments) 10 to 14 days after the tumor was partially or completel y excised. Analysis of the data included information on variables that were hypothesized to influence response to therapy, disease-free inte rval (DFI), or survival time (ST). Other information collected include d age, gender, breed, weight, prior therapy, type of surgery, location of the primary tumor, presence of metastases, number of doses of doxo rubicin, response to doxorubicin therapy (complete or partial response ), and the following histological criteria: overall differentiation, n uclear pleomorphism, percent necrosis, mitotic score, total histologic al score, and grade. Surgery outcome (complete versus incomplete surgi cal excision) markedly influenced survival times (P < .001). Twenty pe rcent of the dogs rendered free of disease were alive at 1 year, where as none of the dogs that had residual tumor after surgery were alive a t 1 year. Most of the histological criteria (nuclear pleomorphism, mit otic score, grade, overall differentiation) had marked (P < .05), or c lose to marked, independent associations with ST for dogs that had com plete tumor removal. Results from analysis of DFI were generally simil ar to those of ST in dogs with complete excision of the tumor. Twenty- seven of the 46 dogs (58.7%) had ail clinical evidence of tumor succes sfully removed. Logistic regression analysis of surgical outcome (abil ity to remove all visible tumor) suggested that age of the subject was the only factor markedly influencing surgical outcome (P = .017). As age increased, the probability of success increased, Those dogs that h ad previous treatment for their hemangiosarcoma tended (P = .08) to ha ve a shorter DFI and Si. Therefore, complete removal of all evidence o f tumor followed by 5 doses of doxorubicin may be an effective treatme nt for dogs with hemangiosarcoma. Dogs that had all tumor successfully removed had a mean and median ST of 267 and 172 days, respectively. D ogs with incomplete tumor removal had a mean and median ST of 172 and 60 days, respectively. Similarly, prognostic variables such as the abi lity to completely excise all evidence of tumor, histological criteria , and age of the patient are potentially important prognostic variable s for predicting outcome. Copyright (C) 1996 by the American College o f Veterinary Internal Medicine.