Osteosarcoma

Overview for Osteosarcoma:

• There are a few different types, which behave differently due to their biological makeup (e.g. conventional/telangiectatic = high grade; juxtacortical/well differentiated, parosteal = low grade) 
• Accounts for approximately 20% of primary bone sarcomas.
• Usually occurs between 10-20 years of age.
• Can also affect those who are 50-60 years of age (often related to patients with Paget's disease or those who received radiation).
• Most common sites are: distal femur, proximal tibia, proximal humerus and proximal femur, although any bone may be involved.

Presentation:

• Localized deep pain, enlarging firm mass, decreased range of motion of body part, night pain.
• Overlying skin may be warm, red with prominient and visible veins.
• Sometimes the tumor is found incidentally following a trauma (i.e. sports injury) where symptoms persist.
• With advanced disease, some have notable weight loss and may present with lung nodules.
• Sometimes there is an increase in the blood level of alkaline phosphatase.

Imaging:

• X-rays show a destructive bone lesion that permeates the cortex (breaks through the side of the bone) forming a large soft tissue mass.
• 90% of these tumors extend into the soft tissue.
• Additional imaging with MRI or CT helps identify extent of the tumor
• A bone scan shows significant uptake of the contrast dye

Determining Diagnosis:

• Bone biopsy with conscious sedation done by our musculoskeletal radiologist.
• Initial staging scans (e.g. bone scan, chest CT, MRI) to determine if the disease is localized or has spread (metastasized).
• Our sarcoma pathologists confirm diagnosis, which may take up to 1-2 weeks due to the specialized testing of tissue. Malignant bone tumors are graded 1 (low), 2 (intermediate), 3 (high), depending on how aggressive the tumor is. 

Treatment:

• Preop chemotherapy (usually 3 months duration with a treatment break of 3-4 weeks before surgery for blood counts to recover).
• Low-grade osteosarcomas do not require chemotherapy. Treatment is surgery only.
• Surgery: type of procedure depends on tumor location and best functional outcome for the limb (e.g. limb sparing procedures using allograft or metal reconstruction, amputation).
• Completion of postop chemotherapy.
• Physical therapy (PT) is necessary to regain the maximum function (range of motion and strength) of the operative limb. Depending on the extent of surgical reconstruction, patients benefit from ongoing PT for up to a year following surgery.
• If local recurrence or distant metastases occur, different chemotherapy drugs are used with additional surgery and/or radiation.
• Surveillance: After the initial postop visits (typically at 2 and 6 weeks), routine surveillance is for 10 years with imaging:
  • Every 3 months for 2 years
  • Then every 6 months for 3 years, which equals 5 years of follow-up
  • Annual visit thereafter for 5 more years, which concludes the surveillance standard of care of 10 years (but most patients like to continue with an annual visit)