Background Flashcards
Describe the histologic defining feature of osteosarcoma.
Production of immature osteoid bone is the defining feature of osteosarcoma. Most are high-grade intramedullary tumors.
What is the difference b/t conventional osteosarcoma and juxtacortical osteosarcoma?
Conventional or “classic” osteosarcoma refers to the most common (75%) variant of osteosarcoma, typically presents within areas of rapidly proliferating intramedullary bone. Juxtacortical osteosarcoma is a less frequently seen osteosarcoma variant that arises adjacent to the outer surface of the cortical bone. (Calvert GT et al., Sarcoma 2012)
Describe juxtacortical osteosarcoma in terms of pathologic grade and prognosis.
Juxtacortical osteosarcoma is usually low-grade (parosteal) or intermediate-grade (periosteal) although high-grade surface osteosarcoma exists in lesser frequency. Parosteal osteosarcoma is curable with Sg alone. Periosteal osteosarcoma has appx a 20% risk of mets and the role of chemo is controversial. (Grimer RJ et al., Eur J Cancer 2005)
What is the incidence of osteosarcoma in the United States population?
In people younger than 25, the age-adjusted incidence is 4.4 per million. In the elderly (age >60) the age-adjusted incidence is 4.2 per million. For adults b/t these 2 age groups (25–60) the age-adjusted incidence is only 1.7 per million.
Name the 2 most common types of malignant bone tumors in the pediatric population.
The 2 most common types of malignant bone tumors in the pediatric population are osteosarcoma (55% of total) and EWS (36% of total). Both cancers are relatively rare accounting for less than 1% of all cancers diagnosed in the United States. (SEER 2009)
Describe the distribution of osteosarcoma cases as a function of population age.
Osteosarcoma has a bimodal distribution as a function of age, with the majority of cases occurring during the teenage yrs with a 2nd period of increased incidence in the elderly (age >60 yrs). The osteosarcomas that develop later in life are often associated with other conditions (Paget Dz, fibrous dysplasia).
Osteosarcoma is associated with what other pediatric tumor?
Pts with retinoblastoma have an increased risk of osteosarcoma, both within and outside the irradiated tissue (i.e., the osteosarcoma can occur as a secondary malignancy within bone that rcvd RT or in distant long bone sites, putatively d/t the germline mutation, which increases risk of both retinoblastoma and osteosarcoma).
What genetic syndromes are associated with osteosarcoma?
Osteosarcoma is associated with Li-Fraumeni syndrome, retinoblastoma and RecQ helicase gene syndromes. Inactivation of tumor suppression pathways is common in osteosarcoma.
Describe the sex and racial factors associated with osteosarcoma.
Osteosarcoma is more common in boys. Incidence is higher for ages 0–24 yrs in the Asian/Pacific Islander population and in the Black population for ages ≥25. (SEER 2009)
What are the most common risk factors associated with the development of osteosarcoma?
A high rate of bone production and turnover (as in puberty or Paget Dz) is associated with the development of osteosarcoma. Osteosarcoma is also the most common secondary cancer in adults who rcvd RT or chemo for a childhood solid tumor.
Osteosarcoma is most likely to develop in which bones and in what part of those bones?
Osteosarcoma arises most frequently in the appendicular skeleton (80% of cases), most commonly at the metaphyseal portions of the distal femur, proximal tibia, and humerus.
What are the 2 most common presenting Sx of osteosarcoma?
Pts with osteosarcoma typically present with localized bone pain (often associated with an injury) of several mos duration and a ST mass.
What % of osteosarcoma pts have localized Dz at Dx?
90% of pts with osteosarcoma have localized Dz at Dx.
What % of osteosarcoma pts with localized Dz will develop DMs without chemo?
90% of pts with localized Dz will develop mets without chemo. (Link M et al., Clin Pediatr Oncol 1991) Chemo is now a standard part of Tx for localized osteosarcoma.
