Treatment/Prognosis Flashcards
What is the standard Tx paradigm for conventional or high-grade osteosarcoma?
Standard Tx paradigm for osteosarcoma is: neoadj chemo → surgical resection → adj chemo.
What data support the use of multiagent chemo in the management of osteosarcoma?
Multiple randomized studies have established the role of adj and neoadj chemo in osteosarcoma management. Link et al. was one of the 1st studies that compared multiagent chemo to no adj management in 36 pts who underwent definitive Sg. At 2 yrs, the RFS was 17% in the control group and 66% in the Tx group. (NEJM 1986) Further studies show that doublet chemo using doxorubicin and cisplatin are better tolerated with no difference in survival for localized, operable osteosarcoma. (Souhami RL et al., Lancet 1997)
What determines a “good” response to neoadj chemo and how does that response relate to overall prognosis?
> 90% necrosis of the postop pathology specimen is considered a “good” response. These pts have significantly higher event-free and OS rates.
Is there data to support changing or intensifying the adj chemo regimen if the pt’s tumor was not a “good” responder to neoadj chemo?
Despite the link b/t pathologic response to neoadj chemo and prognosis, numerous trials among cooperative groups, including the international multigroup EURAMOS-1 trial, did not provide convincing evidence that changing or intensifying postop chemo regimens improves outcomes.
Under what conditions might RT be used in the management of osteosarcoma?
(1) Pts with a close or positive surgical margin (SM) that cannot be improved surgically, (2) surgically inoperable lesions, (3) palliation of painful primary tumors in pts with metastatic Dz, (4) possible SBRT to nonoperable oligometastatic Dz in the lung.
What is the preferred dose of RT for management of an unresectable osteosarcoma or following an R2 resection (definitive paradigm)?
For unresectable Dz, a dose of at least 60–70 Gy is recommended. The preferred dose following an R2 resection is >55 Gy with boost to 64–68 Gy to the area of highest risk. In 1 retrospective review, pts receiving doses of >55 Gy had improved LC.
(DeLaney TF et al., IJROBP 2005)
What radioisotopes are currently being investigated for use in the management of osteosarcoma?
Samarium-153-EDTMP is a bone-seeking radioisotope taken up during osteoid formation that has been investigated and found to be safe in pts with poor prognosis that have been heavily treated already with chemo. Early trials of this approach have shown marginal benefit. Trials investigating the use of Radium-223 to treat metastatic osteosarcomas are also underway.
What is the 5-yr survival rate for nonmetastatic and metastatic osteosarcoma treated with chemo and Sg?
The 5-yr survival for localized osteosarcoma treated with chemo and Sg is 50%–70% but for metastatic osteosarcoma the survival is closer to 20%.
