HIV patients living without the benefit of modern drugs are far more vulnerable to several different types of cancer, say researchers.
HIV weakens the immune system
The research reinforces the connection between the virus and cancers.
The research, carried out at Glasgow and Strathclyde Universities using the Scottish Cancer Registry, used records taken before the introduction of modern antiretroviral treatments.
They found that HIV patients living at this time were overall 11 times more likely to develop a cancer.
However, the risk of certain cancers was far higher.
Kaposi's Sarcoma - a known Aids-related cancer - was 2,000 times more likely in these patients.
Similarly, non-Hodgkin's lymphoma was approximately 100 times more likely.
Surprisingly, however, rates of other cancers, such as liver cancer, lung cancer and skin cancer also soared in these patients.
And there were significant differences between different groups, with homosexual and bisexual men apparently far more at risk compared with HIV positive haemophiliacs and heterosexuals.
Report author Dr Gwen Allardice of the University of Strathclyde, said: "We expected a number of cancers already linked to HIV would be more common in Scottish patients, but the rises in lung, liver and skin cancer were more surprising.
"It could be that HIV patients are smoking more or have greater exposure to other viruses such as hepatitis B and C, or it might be because a healthy immune system plays a stronger role than we though in keeping these cancers at bay."
The pivotal role of the immune system in preventing the emergence of cancers is increasingly clear.
It is thought that several cancer types are associated with infections, and a weakened immune system - such as that found in a HIV patient - is less able to mop these up.
Dr Richard Sullivan, from the Cancer Research UK, said that the report could help doctors monitor the health of present-day HIV patients.
He said: "HIV takes efect by dismantling the immune system.
"It not only strips people of their ability to fight infections, some of which can cause cancer, but may also prevent the body from being able to recognise and destroy cancer cells.
"With this study, we have a valuable insight into the kinds of cancers which are linked to HIV."