Research
has produced conflicting data about rates of cancer in people with HIV. While
the incidence of AIDS-related cancers such as Kaposi’s sarcoma
(KS) have decreased thanks to effective combination
antiretroviral therapy, the incidence of some other types of cancer have risen
as HIV positive people live longer in the HAART
era
In
the July 7, 2007 issue of The Lancet, Australian researchers presented
the results of a meta-analysis of cancer rates in people with HIV and in transplant
recipients, who receive long-term immunosuppressive therapy to prevent organ rejection.
Large population-based studies in transplant patients have shown that a wider
range of cancers (beyond those traditional considered AIDS-defining) could be
associated with immune deficiency.
Investigators
identified eligible studies through searches of PubMed
and reference lists. Random-effects meta-analyses of log standardized incidence
ratios (SIRs) were calculated by type of cancer for
both immune-deficient populations.
Results
·7
studies of people with HIV/AIDS (which included a total of 444,172 subjects) and
5 studies of transplant recipients (with a total of 31,977 subjects) were included.
·There were
42,000 total cancer cases in the HIV positive group and 3000 in the transplant
group.
·For 20 of
the 28 types of cancer examined, there was a significantly increased incidence
in both groups compared with the general
population.
·Many of
these cancers occurred more often in people with HIV/AIDS relative to transplant
recipients.
·Most of
these were cancers with a known infectious cause, including:
ohuman papillomavirus
(HPV), which causes oral and anogenital malignancies including cervical and anal cancer;
oEpstein-Barr
virus (EBV), which is linked to non-Hodgkin’s lymphoma (NHL) and Hodgkin’s lymphoma;
ohuman herpesvirus
type 8 (HHV-8), associated with KS;
ohepatitis
C virus (HCV), which can cause liver cancer (as can hepatitis B virus [HBV]);
oHeliobacter pylori, bacteria associated with stomach
cancer.
·Higher rates
were found for:
oall 3 types
of AIDS-defining cancer (KS, NHL, and cervical cancer);
oall cancers
related to HPV;
oHodgkin’s
lymphoma (HIV/AIDS meta-analysis SIR 11.03; transplant recipients SIR 3.89);
oliver cancer
(HIV/AIDS SIR 5.22; transplant SIR 2.13);
ostomach cancer (HIV/AIDS SIR 1.90; transplant SIR 2.04).
·Most common
epithelial cancers (e.g., breast, ovarian, prostate) did not occur at increased
rates in people with HIV/AIDS or transplant recipients compared
with the general population.
·However,
epithelial cancer of the lungs and bronchial system did occur more often in both
people with HIV and transplant recipients.
·4 other
types of cancer occurred more often in people with HIV and transplant recipients
compared with the general population:
okidney cancer;
omultiple
myeloma;
oleukemia;
omelanoma.
·Bladder
and thyroid cancer and colorectal cancer rates were elevated in transplant recipients,
but not people with HIV/AIDS.
·Conversely,
brain and testicular cancer rates were elevated in people with HIV/AIDS but not
transplant recipients.
Conclusion
“The
similarity of the pattern of increased risk of cancer in the 2 populations suggests
that it is immune deficiency, rather than other risk factors for cancer, that
is responsible for the increased risk,” the authors concluded. “Infection-related
cancer will probably become an increasingly
important complication of long-term
HIV infection.”
They
added that their meta-analysis suggests that, “the range of infection-related
cancers associated with immune deficiency is much wider than previously appreciated
and that a range of infectious organisms seems to be implicated.”
07/13/07
References
AE Grulich, MT van Leeuwen, MO Falster, and others.Incidence of cancers in people with HIV/AIDS compared with immunosuppressed
transplant recipients: a meta-analysis. The Lancet370(9581):
59-67. July 7, 2007.
G
Clifford and S Francheschi.Immunity, infection and cancer.The Lancet 370(9581): 6-7. July 7, 2007.
