Clinical Outcome of Nonnasal Chondrosarcoma in Dogs: Thirty-One Cases (1986-2003)

To evaluate metastatic rate and survival times of dogs with chondrosarcoma of nonnasal bony sites treated by wide surgical excision. Retrospective study. Dogs (n=31) with chondrosarcoma. Medical records were retrospectively reviewed to identify dogs with chondrosarcoma of bone in potentially surgically accessible sites. When complete information was not available in the medical record, owners and referring veterinarians were contacted by telephone to evaluate the course of disease and survival times. When possible, histopathologic diagnosis was confirmed by a single board certified pathologist and tumors were histologically graded. Dogs treated by wide surgical excision (n=18) had a mean survival time of 3097 days and did not reach median survival time. Dogs untreated except for diagnostic biopsy (n =13) had a median survival time of 523 days and a mean survival time of 495 days. Method of treatment and tumor grade predicted survival time (P=.016 and P=.007, respectively). Metastatic rate was 28% for treated dogs and 15% for untreated dogs, with no significant difference between the 2 groups (P=.39). Wide surgical excision significantly improves survival time for dogs with chondrosarcoma of nonnasal bony sites, but does not affect the likelihood of metastasis. Grade may be prognostic for survival. Surgical excision benefits dogs with chondrosarcoma and can result in prolonged survival times. Metastasis still occurs in ~1 of 4 dogs even after surgical resection.