Devita, Hellman, and Rosenberg's Cancer

LWBK1006-03 LWW-Govindan-Review November 24, 2011 11:19

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

leads to the assembly of VLPs that are morphologically identical to native

virion particles. These VLPs present the epitopes that are necessary for

the development of a high titer neutralizing antisera. HPV-16 and HPV-18

are associated with approximately 70% of cervical cancers and HPV-6

and HPV-11 are associated with 90% of anogenital warts. There are

HPV types other than HPV-16 and 18 that can cause cervical cancer, and

therefore vaccinated individuals at risk should continue to receive cervical

cancer screening. In addition, the duration of protection for the specific

HPV types is unknown. The vaccine has been evaluated in women and

therefore for now is recommended in women only.

Answer 3.36. The answer is D.

EBV is associated with many cancers. EBV nuclear proteins, particu-

larly EBNA2, target the transcription factor RBPJk/CBF1. It is through

this transcription factor that EBV nuclear proteins regulate viral LMP1

promoter and the cellular C-myc promoter. EBV viral protein LMP1

engages the TNF receptor cytoplasmic factors and the death domain

proteins, including TRADD and RIP, which may activate downstream

proteins inducing cellular proliferation and survival. EBV is detected in

approximately 50% of Hodgkin’s lymphoma. EBV is also associated with

many Burkitt’s lymphomas, nasopharyngeal cancers, and some gastric

cancers.

Answer 3.37. The answer is A.

Among patients with AIDS, KS risk is highest in homosexual men. The

risk is much lower among AIDS cases related to blood transfusion and in

pediatric AIDS cases. This difference in the risk of KS is a result of higher

prevalence of HHV8 infection, a known cause of KS, among homosexual

men. This infection could then be transmitted among homosexual patients

with AIDS, placing these patients at a higher risk for KS. The prevalence

of this infection among women and prepubertal children is very low.

Answer 3.38. The answer is B.

HHV8 (also KS’s associated virus KSHV) sequences are found in tumors

of every patient with KS, irrespective of whether the patient is HIV

infected or not. The prevalence of this virus is high in countries whereas

classic KS is common and ranges from 20% in Italy to 60% in sub-Saharan

Africa. In the United States, which has a low incidence of classic KS, the

prevalence of HHV8 infection is 5% to 7%. HHV8 is transmitted by

the sexual route, particularly in homosexual men. However, in countries

with a high incidence of classic KS, seroprevalence is detected in children,

suggesting that other routes of transmission exist. The nonsexual routes

involved in the transmission of this virus are not well defined. The rarity

of KS in the United States, despite the HHV8 prevalence rate of 5%, sug-

gests that other factors are essential for the development of KS. In patients

with AIDS-KS, the HIV infection is the other factor, but the cofactors in

classic KS are not yet identified. EBV is not a cofactor in the development

of KS in AIDS or classic KS.