Devita, Hellman, and Rosenberg's Cancer

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

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

Answer 3.27. The answer is C.

HIV-infected patients are at an increased risk of developing non-

Hodgkin’s lymphoma, including Burkitt’s or Burkitt’s-like lymphomas.

The majority of these lymphomas are B-cell lymphomas, and many are

associated with EBV. In addition to the immunosuppression, it has been

theorized that HIV may contribute to lymphomagenesis via dysregulation

of cytokine production and subsequent alteration of B-cell growth reg-

ulation. HIV does not have a transforming effect on the infected CD4+

T cells.

Answer 3.28. The answer is A.

HCV is an RNA virus that belongs to the Hepacivirus genus of the Fla-

viviridae family of viruses. HCV is transmitted in a majority of the cases by

a percutaneous route. Before 1989, when screening for HCV began, trans-

fusion of contaminated blood products was the most important cause of

HCV infection. Use of contaminated needles by intravenous drug users

remains an important source of the infection. It can also be transmitted

perinatally and via sexual routes. In 10% of the cases, risk factors for

transmission are not identified. The fecal–oral route is not known to be

a route for infection with HCV.

Answer 3.29. The answer is A.

Approximately 1% to 5% of the patients with chronic HCV infection

will develop HCC. The incidence of HCV infection has decreased with

improved screening of blood products for HCV; however, there is a 10- to

20-year lag between HCV infection and cirrhosis, and a 20- to 30-year

lag to developing HCC. This has resulted in the rising incidence of HCC

in previously infected patients. An effective HCV vaccine is not available.

Answer 3.30. The answer is B.

Alcohol consumption or coinfection with HBV greatly increases the risk

of developing HCC in HCV-infected patients. The role of HCV in the

pathogenesis of HCC remains to be fully clarified. The inflammatory

response caused by the HCV infection leads to hepatocyte destruction,

regeneration, and fibrosis. Cellular turnover as a result of the inflamma-

tory response could have a transforming effect leading to the pathogenesis

of HCC. A direct oncogenic role of HCV is unlikely, although there have

been results suggesting that the HCV core protein may have an oncogenic

effect. In addition, infection with different strains of the virus may pose a

different level of risk for development of HCC. Treatment with interferon

and ribavirin can reduce the risk of HCC from HCV infection but cannot

eliminate it.

Answer 3.31. The answer is C.

HBV is a small DNA virus classified as a member of the hepadnavirus

family (for hepatotropic DNA viruses). HBV is the only human virus in

this family. Primary HBV infection produces a subclinical infection or