LWBK1006-29 LWW-Govindan-Review December 9, 2011 15:36
Chapter 29•Cancers of Childhood 409Answer 29.31. The answer is D.
Radiation therapy increases the risk of second malignancies, especially
bone tumors in the area of radiation, predisposes to cataracts, and inter-
feres with normal development of the orbit.Answer 29.32. The answer is D.
Most cases of RMS are sporadic. Inherited cancer predisposition syn-
dromes that increase the risk of developing RMS include Li-Fraumeni,
Beckwith-Wiedemann, and Costello syndromes.Answer 29.33. The answer is A.
Recent analyses of prognostic factors in patients with nonmetastatic dis-
ease have identified distinct risk groups for failure-free survival. For stag-
ing and grouping classifications seePPOTables 50.2.10 and 50.2.11.
Stage I group I/IIa or III orbit (90% survival), stage II group I and II
embryonal tumors, and stage III group I and II embryonal tumors have
greater than 85% survival. Survival is poor (<50%) despite all treatment
modalities in patients with embryonal extremity or alveolar tumors (see
PPOTable 50.2.12 on page 2070), and children with metastatic disease.
Younger children aged less than 10 years fare better.Answer 29.34. The answer is B.
MIBG scans are indicated for neuroblastoma and not RMS. The other
scans and bone marrow samples are necessary in view of dissemination
patterns of RMS that include both hematogenous spread and lymphatic
spread to the draining lymph nodes. Treatment decisions are based on
TNM staging (seePPOTable 50.2.10 on page 2069), and clinical group
is based on extent of resection (seePPOTable 50.2.11 on page 2070).
Prognosis depends on stage, age, clinical group, histology, and primary
site. Orbital, vaginal, and paratesticular tumors have the best prognosis,
whereas extremity and parameningeal tumors are unfavorable. Tumors
that are more than 5 cm and that present in children less than 10 years
of age have a worse prognosis.Answer 29.35. The answer is A.
Orbital tumors are usually of embryonal histology and have excellent
response to radiation and chemotherapy. Surgical resection is only indi-
cated for recurrent disease. The dose of radiation is 45 to 55 Gy over
5 to 6 weeks. Children with group II or III RMS of the orbit have a
5-year progression-free survival rate of 90%. Parameningeal disease (usu-
ally group III) has a 5-year progression-free survival rate of 78% without
CNS involvement and 70% with CNS involvement. Extensive surgeries
are not necessary to sites that produce significant surgical morbidity.Answer 29.36. The answer is C.
Radiation therapy for RMS is indicated only for gross or microscopic
residual disease or regional and metastatic extension. The dose for