Treatment Plan for Osteosarcoma
The standard treatment for high-grade osteosarcoma consists of neoadjuvant chemotherapy, surgical resection with wide margins, and adjuvant chemotherapy, which increases survival rates from 10-20% with surgery alone to over 60%. 1
Initial Diagnosis and Staging
- Comprehensive staging should include local imaging (MRI of the affected bone including adjacent joints) and systemic assessment focusing on lungs and skeleton (chest X-rays, CT scan, bone scan) 1
- Laboratory tests should include alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), as elevated levels correlate with adverse outcomes 1
- Baseline organ function assessment is essential before chemotherapy, including renal function, cardiac function (echocardiogram), and audiogram 1
Treatment Algorithm by Disease Stage
High-Grade Osteosarcoma (Most Common)
Neoadjuvant Chemotherapy
- The most widely used regimen is MAP: high-dose methotrexate (HDMTX), doxorubicin, and cisplatin 1, 2
- Treatment typically lasts 6-9 months total (pre and post surgery) 1
- For patients over 40 years or those who cannot tolerate HDMTX, regimens without methotrexate (AP: doxorubicin and cisplatin) may be used 1
Surgical Management
Adjuvant Chemotherapy
- Continue MAP or modified regimen after surgery 1, 2
- Histological response to preoperative chemotherapy provides important prognostic information 1
- For patients with overt progression on first-line chemotherapy, adjuvant therapy using ifosfamide and etoposide can be considered 1
- Mifamurtide may be offered to patients under 30 years without metastases after surgery in countries where it is approved 1, 2
Low-Grade Osteosarcoma Variants
- Low-grade central and parosteal osteosarcoma are treated by surgery alone without chemotherapy 1
- Complete surgical removal with preservation of function is the aim 1
Craniofacial Osteosarcoma
- Requires referral to a bone sarcoma MDT before surgery 1
- Chemotherapy is considered a standard treatment option despite less defined evidence 1
Management of Metastatic and Recurrent Disease
- For primary metastatic disease, treatment is similar to localized disease plus surgical removal of all metastatic deposits 1
- For recurrent disease, complete surgical resection of all metastases is essential when possible 1
- Repeated thoracotomies for pulmonary metastases may be warranted, as over a third of patients with a second surgical remission survive beyond 5 years 1
- Second-line chemotherapy options include:
Special Considerations
- Pathological fracture does not necessarily require amputation; neoadjuvant chemotherapy may allow the fracture hematoma to contract, enabling subsequent resection 1
- Radiotherapy has limited role in osteosarcoma of extremities but may be used for inoperable situations, axial locations, or palliation 1
- Prophylactic antibiotics are recommended for patients at risk of neutropenic sepsis during chemotherapy 1
Monitoring and Follow-up
- Follow-up intervals: every 6 weeks to 3 months in years 1-2, every 2-4 months in years 3-4, every 6 months in years 5-10, and every 6-12 months thereafter 1
- Each visit should include history, physical examination, and chest X-ray 1
- X-rays of the primary tumor site are recommended every 4 months until the end of year 4 1
- Late metastases may occur >10 years after diagnosis 1
Common Pitfalls to Avoid
- Delaying referral to specialized sarcoma centers, as treatment at reference centers is the accepted standard 1
- Inadequate surgical margins, which increase risk of local recurrence 1
- Failing to recognize that changing adjuvant chemotherapy based on response has not improved outcomes 1
- Overlooking the need for bilateral exploration by open thoracotomy for pulmonary metastases, as CT scans often underestimate the number of metastases 1