Prognosis for Metastatic Osteosarcoma of Femur After Chemotherapy
The 5-year overall survival rate for patients with metastatic osteosarcoma of the femur after chemotherapy is approximately 20-30%, which is significantly poorer than the 60% survival rate seen in localized disease. 1
Prognostic Factors
Negative Prognostic Factors
- Presence of metastatic disease at diagnosis is the most significant adverse prognostic factor, with 2-year event-free survival rates of only 21% compared to 75% in non-metastatic disease 1
- Multiple metastatic sites (especially bone metastases with or without pulmonary involvement) significantly worsen prognosis 1, 2
- Number of metastases - patients with 3 or more lesions have significantly lower 2-year disease-free survival (28%) compared to those with only 1-2 metastatic lesions (78%) 1
- Poor histologic response to preoperative chemotherapy (less than 90% tumor necrosis) correlates with worse outcomes 1, 2
- Elevated serum lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels are associated with more aggressive disease and poorer outcomes 1, 3
- Local recurrence prior to metastasis significantly worsens postmetastasis survival 2
- Age >40 years at diagnosis 1
- Non-extremity tumor location 1
Positive Prognostic Factors
- Complete surgical resection of all metastatic sites is the most important positive prognostic factor 1
- Good histologic response to preoperative chemotherapy (>90% tumor necrosis) 1
- Longer time to first relapse 1
- Solitary metastases have better outcomes than multiple metastases 1, 2
- Unilateral lung metastases have better outcomes than bilateral involvement 1
Survival Statistics
- 5-year overall survival rate: 20-30% for metastatic disease versus 60% for localized disease 1, 4
- 2-year event-free survival: 21% for metastatic disease versus 75% for non-metastatic disease 1
- 2-year overall survival: 55% for metastatic disease versus 94% for non-metastatic disease 1
- Median postmetastasis survival: approximately 22 months 2
- 5-year postmetastasis survival based on risk factors 2:
- No negative prognostic factors: 60.2%
- One negative prognostic factor: 31.6%
- Two or more negative prognostic factors: 3.6%
Treatment Impact on Prognosis
- Complete surgical resection of all metastatic sites significantly improves survival (48% long-term survival with complete resection versus 5% without) 1
- Aggressive multimodal therapy combining chemotherapy with surgical resection of both primary tumor and metastases offers the best chance for survival 1, 4
- Attempts to improve outcomes in poor responders by modifying adjuvant chemotherapy regimens have been largely unsuccessful 1
- High-dose ifosfamide plus etoposide has shown some efficacy in metastatic disease with an overall response rate of 59%, but with considerable toxicity 1
- For patients with limited pulmonary metastases who undergo complete surgical clearance, 5-year survival rates of up to 40% may be achieved 1
Important Considerations
- Approximately 10-20% of osteosarcoma patients present with metastatic disease at diagnosis 1
- The lung is the most common site of metastasis, with bone being the second most common 1, 5
- Approximately 30-40% of patients with initially localized disease and 80% of those with metastatic disease at presentation will eventually relapse 1
- Patients with metastatic disease should be treated with a combination of chemotherapy and metastasectomy when possible 1
- Repeated thoracotomies may be indicated for recurrent pulmonary metastases 1
Despite the overall poor prognosis, a subset of patients with limited metastatic disease, good response to chemotherapy, and complete surgical resection of all disease sites can achieve long-term survival 2, 4.