Osteosarcoma Flashcards
What is the epidemiology of osteosarcoma?
Osteosarcoma is the most common primary bone tumor in children and young adults.
It comprises more than half of all pediatric primary skeletal malignancies.
What age group is most affected by osteosarcoma?
Osteosarcoma most often occurs in people under 20 years old, with teens being the most commonly affected age group.
Osteosarcomas can develop at any age.
How common is osteosarcoma in adults?
Osteosarcoma is the second most common type of primary bone tumor in adults.
It is most common in males.
What is osteosarcoma?
Osteosarcoma is a type of primary bone cancer that occurs at metaphyseal plates.
What age group is at the highest risk for osteosarcoma?
The highest risk is for those between the ages of 10 and 30, especially during the teenage growth spurt.
How does age affect the risk of osteosarcoma?
The risk goes down in middle ages but rises again in older adults (over age of 60).
Osteosarcoma in older adults is often linked to another cause such as a long-standing bone disease.
What is a common characteristic of children with osteosarcoma?
Children with osteosarcoma are usually tall for their age.
Which gender is more likely to develop osteosarcoma?
Males are more likely to develop osteosarcoma.
Which races/ethnicities are at higher risk for osteosarcoma?
African-American and Latino individuals are at higher risk.
What previous medical exposure is a risk factor for osteosarcoma?
Previous radiation exposure is a risk factor.
What bone disease is associated with an increased risk of osteosarcoma?
Paget’s disease is associated with an increased risk.
What genetic conditions are linked to osteosarcoma?
Retinoblastoma, Li-Fraumeni syndrome, and Rothman-Thomson syndrome are linked to osteosarcoma due to mutations of the p53 gene.
What is the most common presenting symptom of osteosarcoma?
Pain
Pain may occur even without a mass that can be felt.
How do patients with osteosarcoma typically describe their pain?
Patients usually experience nonspecific pain and swelling that becomes progressively worse over several months.
What are other common presenting symptoms of osteosarcoma?
Mass, Decreased Range of motion, Fracture
Where does osteosarcoma most commonly occur?
In the long bones around the knee
What are the most common sites for osteosarcoma?
- Distal Femur (near metaphyseal plate)
- Proximal tibia
- Proximal humerus
What is important to determine the duration of symptoms in osteosarcoma?
A complete history of the patient is important.
What imaging is used at the primary tumor site for osteosarcoma?
X-ray of primary tumor site.
How does osteosarcoma appear on an X-ray?
It appears as a tumor permeating the medullary cavity with a classic ‘onion skin’.
What imaging is used to rule out lung metastasis in osteosarcoma?
Chest CT.
What is the key indicator of malignancy on a radiograph?
The characteristic of the margin.
What percentage of cases with well-defined sclerotical borders are malignant?
A legion with well-defined sclerotical borders is malignant in only 6% of cases.
Why is MRI used in instances of aggressive bone tumors?
Because of the accuracy in distinguishing healthy tissues and neurovascular structures from the tumor tissue.
What is essential in planning a surgical biopsy and treatment?
MRI is essential.
What does MRI demonstrate in relation to osteosarcoma tumors?
MRI is highly sensitive, demonstrating the reactive zone of the tumor in the bone while differentiating marrow edema adjacent to tumor tissue.
What future imaging technique may be used in the diagnosis and staging of primary bone tumors?
PET/MRI.
What is the benefit of PET/MRI in osteosarcoma?
It is an excellent tool for evaluation of tumor size before surgery and can be used to monitor progress after neoadjuvant therapy.
What is the sensitivity of bone scans in detecting tumors?
Bone scans are extremely sensitive and can detect tumors in bone that are not yet visualized on diagnostic radiographs.
What is the chance of an osteolytic lesion with less defined edges being malignant?
An osteolytic lesion with less defined edges on a radiograph has a 50% chance of being malignant.
What is the most important step in confirmation of a pathologic diagnosis?
Biopsy for confirmation of diagnosis.
What must be discussed with the surgeon and radiation oncologist before a biopsy?
The biopsy site and approach.
What are the preferred methods for biopsy?
Typically, a core needle biopsy or open biopsy is the preferred method.
What is one disadvantage of open biopsy?
The risk of tumor cell seeding.
What is osteosarcoma?
Osteosarcoma is a type of primary bone tumor.
What are the grades of osteosarcoma tumors?
Tumors are classified as either low grade (G1) or high grade (G2).
How do low grade and high grade tumor cells differ?
Low grade tumor cells resemble normal cells and are less likely to grow and spread quickly, while high grade tumor cells appear more abnormal.
What are the histologic subtypes of osteosarcoma?
The histologic subtypes include osteoblastic, chondroblastic, and fibroblastic.
What is the Enneking staging system?
The staging system for osteosarcomas. It has been adjusted by the AJCC.
What has updated the Enneking staging system and how?
It has been updated by the AJCC to replace compartmentalization with tumor size.
How are osteosarcomas generally classified?
Osteosarcomas are generally classified as poorly differentiated high grade tumors.
What is the most aggressive subtype of osteosarcoma?
The osteoblastic subtype is the most aggressive and is considered high grade.
What is the grade of the chondroblastic subtype? How does it present?
The chondroblastic subtype is considered intermediate grade and presents as periosteal lesions.
How is the fibroblastic subtype classified in osteosarcoma?
The fibroblastic subtype is a low grade subtype that commonly presents as a parosteal tumor.
What is the staging system for osteosarcomas?
The Enneking staging system
How are osteosarcomas generally classified?
Osteosarcomas are generally classified as poorly differentiated high grade tumors.
What are the histologic subtypes of osteosarcoma?
The histologic subtypes of osteosarcoma include:
1. Osteoblastic - most aggressive subtype and is considered high grade.
2. Chondroblastic - considered intermediate grade in which periosteal lesions are histologically classified.
3. Fibroblastic - low grade subtype which commonly presents as a parosteal tumor.
What is the most common site of metastasis in osteosarcoma?
The lungs.
What percentage of patients with high-grade osteosarcoma develop lung metastases within 2 to 3 years?
Approximately 90%.
What are skip metastases in osteosarcoma?
A second, smaller focus of osteosarcoma in the same bone or a second bone lesion on the opposing side of a joint space.
What contributes to the phenomenon of skip metastases?
The extensive spread by the lesion into the marrow cavity of the bone.
Why is control of bone tumors difficult?
Due to the overall aggressiveness of bone tumors.
When is lymphatic spread of bone tumors a concern?
When the tumor arises in the trunk of the body.
What increases the chance of lymphatic invasion by bone tumors?
The prominence of lymph vessels and nodes in the trunk of the body.
What is the treatment approach for osteosarcoma?
The treatment requires a multidisciplinary approach due to its chemo-sensitivity and radioresistance.
What does the current accepted treatment for osteosarcoma consist of?
It consists of neoadjuvant, multiagent chemotherapy, surgical resection of the primary tumor, followed by additional chemotherapy.
What was the historical treatment for the primary lesion in osteosarcoma?
Historically, the treatment was amputation, which achieved excellent local control but had unsatisfactory outcomes for life and functionality.
How have amputation rates changed over the years for osteosarcoma treatment?
Amputation rates have declined due to the evolution of new chemotherapy treatments, leading to a shift towards limb-sparing surgery.
What is limb-sparing surgery in the context of osteosarcoma?
In limb-sparing surgery, the bone involved with the tumor is removed and reconstructed with an implant.
Is radiation part of the standard treatment regimen for osteosarcoma?
No, radiation is not part of the standard treatment regimen for patients with osteosarcoma.
What is the typical treatment plan for Osteosarcoma?
Multidisciplinary approach including neoadjuvant chemotherapy, limb-sparing surgery, and adjuvant chemotherapy.
What are the key components of adjuvant chemotherapy for Osteosarcoma?
Cisplatin, Doxorubicin, Methotrexate with Leucovorin.
What is a characteristic of Osteosarcoma regarding radiation treatment?
It is radioresistant with no definitive radiation treatment.
What is advised for patients with positive surgical margins and partial resections who are nonsurgical candidates?
External beam therapy is advised for these patients.
What is the postoperative dose for high-risk anatomic sites in osteosarcoma treatment?
64-68 Gy to the high-risk anatomic site.
What is the dose for unresectable tumors in osteosarcoma treatment?
70 Gy.
What are common side effects of radiation therapy of osteosarcomas?
Skin reactions, reduced blood counts, and fractures.
What complications can arise from the treatment of osteosarcoma?
Nephrotoxicity and neurotoxicity from chemotherapy.
When are more side effects typically experienced in osteosarcoma treatment?
More side effects are normally experienced when several modalities are used in combined sequence.
What is the most important prognostic indicator for osteosarcoma?
The presence or absence of metastases at the time of diagnosis.
What percentage of osteosarcoma patients have distant metastasis at presentation?
Approximately 15-20% of patients.
How does gender affect the prognosis of osteosarcoma?
Prognosis is typically worse in males.
What age and gender has a worse prognosis for osteosarcoma?
Males younger than 10 years of age.
How does the duration of symptoms affect prognosis?
Prognosis is typically worse if the duration of symptoms is less than 6 months.
What factors are considered in the prognosis of osteosarcoma?
Grade and stage at time of diagnosis, duration of symptoms, and interval between chemotherapy and surgery.
What is the overall 5-year survival rate for osteosarcoma?
63%
What is the 5-year survival rate for males with osteosarcoma?
59%
What is the 5-year survival rate for females with osteosarcoma?
70%
What is the 5-year survival rate for osteosarcoma patients with no metastasis?
70%
What is the 5-year survival rate for osteosarcoma patients with metastasis?
30%
