People with both HIV and hepatitis B have a higher rate of
non-liver cancers compared to other people with HIV, a large European study has
found.
The study investigators, who have published their findings
in the journal HIV Medicine, say that people with HIV and
hepatitis B co-infection may need extra screening for some common cancers. The study found
that the rate of non-liver cancers was 23% higher in people with HIV and
hepatitis B compared to people with HIV alone.
Viral hepatitis (hepatitis B or C) raises the risk of
hepatocellular carcinoma (liver cancer). Studies of people with hepatitis B
alone also show a raised risk of some non-liver cancers but the risk of
non-liver cancers in people co-infected with hepatitis B and HIV is unclear.
Glossary
- lymphoma
A
type of tumour affecting the lymph nodes.
To investigate whether hepatitis B raises the risk of
non-liver cancers in people with HIV, Professor Amanda Mocroft of University
College London and colleagues in the EuroSIDA cohort collaboration looked at
people with HIV enrolled in the EuroSIDA cohort whose hepatitis B status was
known.
The study identified 17,485 people who had been tested for
hepatitis B surface antigen (a marker of chronic hepatitis B infection) and who
had a baseline CD4 count and viral load recorded. The cohort was predominantly
male (73%), White (85%) and 39% had co-infection with hepatitis C. Eighty-four
per cent were taking antiretroviral therapy and the median Cd4 cell count was
440.
Just over 7% of the cohort (1269 people, 7.2%)
had chronic hepatitis B infection while 931 out of 1269 had at least one
positive HBV DNA measurement during a median follow-up period of 7.4 years. A
positive HBV DNA result indicates that hepatitis B virus is replicating.
Antiretroviral regimens that contained drugs which suppress
hepatitis B – lamivudine, emtricitabine, tenofovir disoproxil or tenofovir
alafenamide – were used more frequently as time went on. Whereas approximately
65% of people with hepatitis B were taking at least one HBV-suppressive drug at
the beginning of the follow-up period in 2002, by 2019 around 90% were taking
at least one HBV-suppressive drug and approximately 70% were taking tenofovir
disoproxil or tenofovir alafenamide plus lamivudine or emtricitabine.
Between 2001 and 2019, 1298 people in the sample developed
1360 non-liver malignancies, an incidence of 8.55 cases per 1000 person-years
of follow-up. The incidence was higher in people with hepatitis B (10.54 vs
8.42 per 1000 PYFU). Multivariable analysis that adjusted for demographic and
HIV-related factors, smoking and liver fibrosis showed that people with
hepatitis B and HIV had 23% higher incidence of non-liver malignancies
(incidence rate ratio 1.23).
When compared to people with hepatitis B who were
HBV-DNA-negative, people with hepatitis B who were HBV-DNA-positive had a 37%
higher rate of non-liver cancers. People with HIV and hepatitis B who had any
exposure to HBV-suppressive antiretrovirals did not have a raised risk of
non-liver cancers when compared to people without hepatitis B. But if they had
not been exposed to HBV-suppressive drugs, the rate of non-liver cancers was
45% higher in people with HIV and hepatitis B compared to people with HIV alone.
The most common cancers were anal cancer (188 cases), lung
cancer (147 cases) and non-Hodgkin lymphoma (131 cases). The investigators
found a non-significant trend towards a higher rate of anal cancer in people
with hepatitis B and HIV and a significantly higher rate of non-Hodgkin
lymphoma in people who were HBV-DNA-positive (adjusted incidence rate ratio 2.57).
However, in both cases the absolute number of cases in people with hepatitis B
was small.
The study investigators say it’s unclear why hepatitis B
might lead to a higher rate of some cancers, and they recommend further investigation
of the link in other cohorts, including the question of whether higher HBV DNA
levels are associated with higher rates of any non-liver cancers. If the link
is confirmed, they conclude, increased cancer screening in people with HIV and
hepatitis B may be appropriate.