Devita, Hellman, and Rosenberg's Cancer

LWBK1006-29 LWW-Govindan-Review December 9, 2011 15:36

408 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

no treatment. Allogeneic transplants have not demonstrated a definite

benefit to date.

Answer 29.26. The answer is C.

Neuroblastoma as described in the question is a special entity. It has a

high rate of spontaneous remission and excellent survival. Intermediate-

risk neuroblastomas, a rare subgroup (10% to 15%) generally in older

children, are generally large and localized. Surgery and moderately intense

chemotherapy results in 4-year event-free survival (EFS) rates of 54% to

100%.

Answer 29.27. The answer is B.

The majority of retinoblastomas are sporadic and unilateral (70% to

75%). The median age at diagnosis is 1 to 2 years. Between 10% and

15% of patients with unilateral retinoblastoma have germ line mutations

of chromosome 13q14. Between 25% and 30% of children with sporadic

retinoblastoma have bilateral disease and carry germ line mutations of

13q14. The median age at diagnosis is less than 12 months.

Answer 29.28. The answer is D.

The risk of dissemination of retinoblastoma is determined by the extent of

ocular tumor and is increased by involvement of the choroid, optic nerve,

anterior chamber, ciliary body, and orbit. Lumbar puncture, bone mar-

row, and bone scan should only be performed in patients with extraocular

involvement or in the presence of symptoms and signs of involvement of

distant sites.

Answer 29.29. The answer is D.

Cryotherapy, hyperthermia, and photocoagulation can be used instead

of enucleation for unilateral or bilateral localized disease that does not

involve the globe or the anterior chamber to preserve vision. Enucleation,

where indicated, should include a 10- to 15-mm length of optic nerve to

obtain a tumor-free margin. External beam radiation including the entire

orbit and optic nerve up to the optic chiasm (44 to 50 Gy) is indicated for

orbital involvement. For intraocular or recurrent disease, chemotherapy

agents (vincristine, etoposide, cyclophosphamide, doxorubicin, cisplat-

inum, and cyclosporin A as an multidrug resistance-reversing agent) are

used in combination with other modalities to preserve vision or avoid

enucleation, or as salvage. They are most useful in group I to IV tumors.

However, chemotherapy alone rarely achieves durable control.

Answer 29.30. The answer is A.

There is excellent response to vision-sparing interventions in retinoblas-

toma. These include photocoagulation, cryotherapy, hyperthermia,

plaque radiotherapy, and so forth. Enucleation should only be under-

taken if there is severe inflammation, no salvageable vision, or extraocu-

lar extension at risk for metastatic disease. For staging and classification

of retinoblastoma seePPOTables 50.2.6 and 50.2.7 on page 2055.