Canine mandibular osteosarcoma: 51 cases (1980-1992)

Abstract

Fifty-one dogs treated for mandibular osteosarcomas (OSs) were studied retrospectively. Treatments were partial mandibulectomy (n = 32); partial mandibulectomy and chemotherapy (n = 10); partial mandibulectomy and radiation therapy (n = 3); partial mandibulectomy, radiation therapy, and chemotherapy (n = 4); and radiation therapy alone (n = 2). The overall one-year survival rate was 59.3%. Dogs treated with surgery alone had a one-year survival rate of 71%, which is higher than the one-year survival rate for dogs with appendicular OSs treated with surgery alone (p of 0.001 or less; hazard ratio of 0.29). There was no apparent effect of various treatment modalities, nor institution where treatment was given, nor histological type. Histological score and, to a lesser extent, histological grade were predictive of survival outcome.

Evaluation of Clinical and Histopathologic Prognostic Factors for Survival in Canine Osteosarcoma of the Extracranial Flat and Irregular Bones

“…Vascular invasion was identified as present ¼ 1 or absent ¼ 0. Tumor type was identified as osteoblastic (OB), fibroblastic (FB), chondroblastic (CB), telangiectatic (TC), osteofibroblastic (OF), giant cell variant (GC), or osteochondrofibroblastic (OCFB) as described by Slayter et al 17 All samples were assigned a histologic grade of I, II, or III based on the histologic scoring and grading system defined by Straw et al 20 and summarized in Tables 1 and 2.…”

“…Tumor grade, while prognostic in human osteosarcoma, 8 has historically not been consistently prognostic in studies of canine osteosarcoma with several studies showing no prognostic signifigance. 9,20 However, a recent study by Kirpensteijn et al showed a histologic grade of III to be an independent predictor of clinical outcome when cases of canine osteosarcomas from all locations in the body were evaluated. 11 The existence of a grading system that is significantly associated with survival for osteosarcomas, especially for this subset of osteosarcomas for which survival may be longer, would be invaluable for the clinical decision making process.…”

“…22 However, the majority of canine osteosarcomas arise from the appendicular skeleton and it has been suggested that current data are biased towards appendicular tumors and that osteosarcoma of the flat and irregular bones has a different biological behavior and prognosis. 4,10,20 Dogs with mandibular osteosarcoma showed a higher one year survival rate and dogs with rib osteosarcoma showed a higher metastatic rate than dogs with appendicular osteosarcoma. 9,20 Several clinical and histologic criteria have been reported as potential prognostic indicators for osteosarcoma of the flat and irregular bones including anatomic site, 9 weight, 9 completeness of surgical excision, 9 breed, 4 definitive versus palliative radiation therapy, 4 and histologic grade.…”

“…9,20 Several clinical and histologic criteria have been reported as potential prognostic indicators for osteosarcoma of the flat and irregular bones including anatomic site, 9 weight, 9 completeness of surgical excision, 9 breed, 4 definitive versus palliative radiation therapy, 4 and histologic grade. 20 However, these papers included only small numbers of cases from locations other than the rib and mandible. Tumor grade, while prognostic in human osteosarcoma, 8 has historically not been consistently prognostic in studies of canine osteosarcoma with several studies showing no prognostic signifigance.…”

Targeted radiotherapy with Sm-153-EDTMP in nine cases of canine primary bone tumours

“…No local recurrence or metastases were evident 21 months postsurgery. Straw et al 22 reported the use of Sm-153-EDTMP in 2 dogs with mandibular osteosarcoma. One dog was lost to follow-up at 41 months.…”