Cancer Risk In HIV, Transplant Patients
HIV/AIDS and kidney transplant patients are at much greater risk of contracting 20 different types of cancer than the general population.
The research, which is led by Professor Andrew Grulich from the University of New South Wales’ National Centre in HIV Epidemiology and Clinical Research (NCHECR), suggests that immune deficiency – which is common to the two groups – is responsible for the increased risk.
The paper is the first to compare cancer rates between these populations.
HIV/AIDS patients are 11 times more likely to develop Hodgkin’s lymphoma – a cancer associated with Epstein Barr Virus – while there is almost four times the risk for those who have a transplant.
There are a number of cancers associated with human papilloma virus, from cervical cancer to cancers of the mouth, penis and anus. In both these populations, all of these cancers were significantly increased.
“The only thing that people with AIDS and transplant recipients share is immune deficiency, otherwise their risk factors for cancer differ markedly,” said the lead author, Professor Grulich, of the paper, which has been selected for editorial comment in the journal.
“In other cancers, which are not linked with viruses, such as breast and prostate cancer, both groups had similar rates to the general population,” he said.
“Until now, the accepted wisdom was that there were only three cancers associated with HIV – this paper finds that it is more like 20.”
One of those three cancers which was already known to be linked with HIV is Kaposi’s sarcoma. In that population, there is a 3,640-fold increased likelihood for patients to develop the disease. This research shows that there is also a marked increase in transplant patients – they are 208 times more likely to develop the cancer than the general population.
Professor Grulich suggests the results could have implications for the way HIV/AIDS patients are treated.
“This evidence suggests that immune deficiency is associated with risk of cancer and this suggests we need to maintain people’s immune systems at a higher level – and that might mean putting HIV patients on anti-retroviral drugs earlier than is currently the case,” he said.
The researchers now plan to look at cancer rates in those with congenital immune deficiency and people who have received other transplanted organs.
Lancet. 2007 Jul 7;370(9581):59-67.
Incidence of cancers in people with HIV/AIDS compared with immunosuppressed transplant recipients: a meta-analysis.
National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, Australia. firstname.lastname@example.org
BACKGROUND: Only a few types of cancer are recognised as being directly related to immune deficiency in people with HIV/AIDS. Large population-based studies in transplant recipients have shown that a wider range of cancers could be associated with immune deficiency. Our aim was to compare cancer incidence in population-based cohort studies of people with HIV/AIDS and people immunosuppressed after solid organ transplantation. METHODS: Two investigators independently identified eligible studies through searches of PubMed and reference lists. Random-effects meta-analyses of log standardised incidence ratios (SIRs) were calculated by type of cancer for both immune deficient populations. FINDINGS: Seven studies of people with HIV/AIDS (n=444,172) and five of transplant recipients (n=31 977) were included. For 20 of the 28 types of cancer examined, there was a significantly increased incidence in both populations. Most of these were cancers with a known infectious cause, including all three types of AIDS-defining cancer, all HPV-related cancers, as well as Hodgkin’s lymphoma (HIV/AIDS meta-analysis SIR 11.03, 95% CI 8.43-14.4; transplant 3.89, 2.42-6.26), liver cancer (HIV/AIDS 5.22, 3.32-8.20; transplant 2.13, 1.16-3.91), and stomach cancer (HIV/AIDS 1.90, 1.53-2.36; transplant 2.04, 1.49-2.79). Most common epithelial cancers did not occur at increased rates. INTERPRETATION: The similarity of the pattern of increased risk of cancer in the two populations suggests that it is immune deficiency, rather than other risk factors for cancer, that is responsible for the increased risk. Infection-related cancer will probably become an increasingly important complication of long-term HIV infection.
PMID: 17617273 [PubMed – in process]