Introduction
- 85% of all bone tumors (50% of all bone tumors in small breeds).
- 75% of all OSA affect the appendicular skeleton.
- Most commonly affects distal radius; other common sites are distal femur, proximal tibia and proximal humerus.
- Also affects axial skeleton and (rarely) soft tissues (extraskeletal OSA).
- Appendicular OSA most common in large and giant breeds.
- Signs : sudden onset lameness/metaphyseal swelling.
- Treatment : surgery and chemotherapy.
- Prognosis : poor long-term as metastatic spread common, if treated, good short-term prognosis.
Print off the owner factsheet on Canine osteosarcoma
to give to your client.
Diagnosis
Clinical signs
- Swelling at characteristic site.
- Pain on palpation.
Diagnosis
Differential diagnosis
Acute lameness
- Other primary bone tumors
. - Secondary bone tumors (metastatic lesions).
- Osteomyelitis .
- Fungal.
- Bacterial.
- Fractures.
- Other injury/dislocation.
Sequelae
Prognosis
- Very poor without treatment.
- Pain of primary tumor will necessitate euthanasia within weeks of diagnosis.
- Amputation alone will provide a median survival time of 18-25 weeks (50% survival at 6 months; 10% at 1 year).
- Amputation + chemotherapy - best prognosis: 60% survival at 6 months; 33-55% at 1 year; 15-20% at 2 years. Median survival time, 9-11 months.
- Serum alkaline phosphatase above normal range at time of diagnosis is associated with a poorer prognosis and a median survival of 5-7 months.
Reasons for treatment failure
- Chemotherapy not used.
- Detectable metastatic spread at time of diagnosis. Chemotherapy not effective for gross (radiographically visible) metastatic disease.
Sources
Publications
Refereed papers
- Recent references from PubMed.
- Hillers K R, Dernell W S, Lafferty M H, Withrow S J & Lana S E (2005) Incidence and prognostic importance of lymph node metastases in dogs with appendicular osteosarcoma: 228 cases (1986-2003). JAVMA 226 (8), 1364-1367 PubMed.
- Fuchs B & Pritchard D J (2002) Etiology of osteosarcoma. Clin Orth Rel Res 397, 40-52. PubMed
- Dickerson M E, Page R L, LaDue T A et al (2001) Retrospective analysis of axial skeleton osteosarcoma in 22 large-breed dogs. JVIM 15, 120-124.PubMed
- Langenbach A, McManus P M, Hendrick M J, Shofer F S & Sorenmo K U (2001) Sensitivity and specificity of methods of assessing the regional lymph nodes for evidence of metastasis in dogs and cats with solid tumours. JAVMA 218, 1424-1428.PubMed
- Mehl M L, Withrow S J, Seguin B, Powers B E et al (2001) Spontaneous regression of osteosarcoma in four dogs. JAVMA 219, 614-617. PubMed
- Blackwood L (1999) Bone tumours in small animals. JSAP 21, 31.
- Ehrhart N et al (1998) Prognostic importance of alkaline phosphatase activity in serum from dogs with appendicular osteosarcoma - 75 cases (1990-1996). JAVMA 213, 1002-1006.PubMed
- Bergman P J et al (1996) Amputation and carboplatin treatment of dogs with oesteosarcoma - 48 cases (1991 to 1993). J Vet Intern Med 10, 76-81.PubMed
- McEntee M C et al (1993) Palliative radiotherapy for canine appendicular osteosarcoma. Vet Radiol 34, 367-370.
- Ogilvie G K et al (1993) Evaluation of single-agent chemotherapy for treatment of clinically evident oesteosarcoma in dogs - 45 cases (1987-1991). JAVMA 202, 304-306.PubMed
- Berg J et al (1992) Treatment of dogs with osteosarcoma by administration of cisplatin after amputation or limb-sparing surgery - 22 cases (1987-1990). JAVMA 200, 2005-2008.PubMed
- Spodnick G J et al (1992) Prognosis for dogs with appendicular oesteosarcoma treated by amputation alone - 162 cases (1978-1988). JAVMA 200, 995-998.PubMed
- Straw R C, Cook N L, LaRue S M, Withrow S J & Wrigley R H (1989) Radiographic bone surveys. JAVMA 195, 1458 (letter). PubMed
- Powers B E, LaRue S M, Withrow S J, Straw R C & Richter S L (1988) Jamshidi needle biopsy for diagnosis of bone lesions in small animals. JAVMA 193, 205-210. PubMed
- Carberry C A & Harvey H J (1987) Owner satisfaction with limb amputation in dogs and cats. JAAHA 23, 227-232.
