People with HIV
and hepatitis C virus (HCV) co-infection have an increased risk of
non-AIDS-defining cancers compared to people with HIV mono-infection,
investigators from Spain report in the online edition of AIDS. Even after hepatocellular carcinoma was excluded,
co-infection was associated with a 26% increase in the risk of non-AIDS-related
cancers relative to HIV mono-infection.
But both groups had a higher risk of cancer compared to the general
population.
Cancer prevention
and screening should be a top priority in HIV care, suggest the authors, who believe
their results underscore the importance of treating and eradicating HCV in
people with co-infection.
Glossary
- lymphoma
A
type of tumour affecting the lymph nodes.
As a result of
antiretroviral therapy (ART), many people with HIV now have a near-normal
life expectancy. However, rates of serious non-HIV-related illnesses are higher
among people with HIV compared to individuals in the general population. Several
studies have shown that even in the context of effective ART, people with HIV
have an elevated risk of several malignancies not traditionally associated with
HIV infection.
In high-income
countries, approximately a third of people with HIV have HCV
co-infection. This infection has been associated with an increase in
liver cancer and
also with certain other malignancies, including lymphoma.
Little is known
about the impact of HCV co-infection on cancer risk for people with HIV.
Investigators in
Coruña therefore designed a retrospective study involving adults with
HIV who received care between 1993 and 2014. Incidence of cancer was
compared between people with HIV and individuals in the general
population. The investigators also compared cancer risk for people with
HIV according to HCV co-infection status.
The study
population consisted of 2318 people, 37% of whom had HCV co-infection.
Only 17% of people with HIV and HCV co-infection had received HCV therapy (interferon based
in all cases) and 48% of those who had received HCV therapy had a sustained virological response.
Study participants were
followed for an average of twelve years and contributed 27,086 person-years of
follow-up. A total of 185 people, 68 of whom had HCV co-infection, were diagnosed
with a cancer. Overall cancer incidence was 696 cases per 100,000 person years.
Incidence of
non-AIDS-defining cancers was higher among people with HIV and HCV co-infection compared to
people with HIV mono-infection (415 vs 377 per 100,000 person-years).
Cancer incidence
overall was almost four-fold higher among people with HIV compared to
the general population (SIR = 3.8; 95% CI, 3.3-4.4).
Unsurprisingly, people with HIV had a massively increased incidence of
AIDS-related cancers compared to individuals in the wider population
(SIR =
27.2; 95% CI, 21.7-33.8). But HIV infection was also associated with a
more
than two-fold increase in the incidence of non-AIDS-related malignancies
(SIR =
2.3; 95% CI, 1.9-2.80). This increased risk was present for people with
HIV-mono-infection (SIR = 1.8; 95% CI, 1.3-2.3) and especially those
with HCV co-infection (SIR = 3.4; 95% CI, 2.5-4.4).
As expected,
incidence of AIDS-related cancers fell during follow-up but rates of non-AIDS-related
cancers increased.
Older age was a
risk factor for diagnosis with cancer. This was the case for both HIV-related
and non-HIV-related malignancies.
People with HCV
co-infection had a significantly increased risk of diagnosis with a
non-AIDS-related cancer compared to people with mono-infection (SHR = 1.80;
95% CI, 1.15-2.81). Co-infection remained associated with increased risk of
non-HIV-related malignancies after diagnosis with liver cancer was excluded
(SHR = 1.26; 95% CI, 1.02-1.94).
“After adjusting
for epidemiological factors and mortality without cancer,
HIV/HCV-co-infected
patients presented more NADC [non-AIDS-defining cancer] than
HIV-mono-infected, even after excluding HCC [hepatocellular carcinoma],”
conclude the authors. “Treatment of HCV infection and HIV replication
control
are fundamental strategies but the valuable role of cancer-screening
programs
and early treatment must be assessed.”