LWBK1006-26 LWW-Govindan-Review December 12, 2011 19:29
Chapter 26•Sarcomas 371sarcoma requires knowledge of histologic grade, size, depth, and presence
of metastatic disease.Answer 26.7. The answer is C.
Positive surgical margin predicts a higher risk of local recurrence. Re-
resection in an attempt to achieve negative surgical margins would be the
next most appropriate step in the management of this patient. If negative
surgical margins are achieved after re-resection, adjuvant radiation would
not be required. Adjuvant chemotherapy would have no clear benefit in
this case.Answer 26.8. The answer is A.
Soft tissue sarcoma of the head and neck is associated with a poor prog-
nosis. Angiosarcoma has a higher risk of nodal metastases and local recur-
rence after resection alone. Adjuvant radiation reduces the risk of local
and regional disease recurrence. Although angiosarcomas tend to be sen-
sitive to anthracyclines and taxanes, there would be no known benefit of
adjuvant chemotherapy in this case.Answer 26.9. The answer is C.
Intra-abdominal leiomyosarcomas and GISTs have similar characteris-
tics by light microscopy; however, GISTs stain positive for the CD117
(c-Kit) protein, whereas leiomyosarcomas usually do not. Leiomyosarco-
mas frequently respond to chemotherapy, whereas GISTs do not. How-
ever, GISTs are uniquely responsive to c-Kit inhibitors. In this case, a c-Kit
immunostain should be requested to determine whether the sarcoma is
a GIST and not a leiomyosarcoma. Because this patient has metastatic
disease, systemic therapy would be favored over palliative radiation.Answer 26.10. The answer is C.
Resection of the primary tumor with intent to achieve negative surgical
margins followed by adjuvant radiation would be the most appropriate
treatment of a large high-grade extremity liposarcoma. Definitive radi-
ation with or without concurrent chemotherapy would be less effective
treatment. Preoperative chemotherapy may be used when the tumor is
marginally resectable, but its role in this situation is controversial.Answer 26.11. The answer is D.
Studies have demonstrated that approximately one-third of patients with
GIST resistant to imatinib 400 mg/d will benefit with increasing the
dose of imatinib to 600 or 800 mg/d. Should that step fail, sunitinib
would be the next most appropriate therapy. GIST is generally resistant
to chemotherapy drugs, such as doxorubicin. Epidermal growth factor
receptor inhibitors, such as erlotinib, would not be expected to benefit
patients with GIST.