Question

I'm worrying about reports of higher risk of HIV and cancer…

27 January 2012. Related: All topics, Life expectancy, Living with HIV long-term.

I have carried out some considerable research since my pos diagnosis in Dec 2011 regarding the high probability of contracting some form of cancer compared with a neg person. Frankly it has left me feeling petrified as it appears that meds are helping us to live longer but only to massively increase our chances of getting cancer. I am really thankful for antiretrovirals but now feel that a poz diagnosis really is a death sentence in one way or another.

Answer

Answer: Simon Collins

Thanks for your question. It is great that you are reading about HIV and treatment and taking an active interest in your own health care.

Over the years this will probably mean you develop a stronger relationship with your doctor and also end up with better health. Sometimes the wealth of information can be daunting though and sometimes news that seems negative gets out of proportion to the bigger picture.

So for HIV care the overwhelming news about treatment is positive. Treatment doesn’t just slow the progression of HIV but it stops it. While you are on treatment with an undetectable viral load the levels of virus are too low to cause nearly all the previous HIV-related complications. They are also usually too low to even cause resistance – so long as you are good at talking your meds.

This has lead to several groups of researchers predicting that life expectancy is now similar to an HIV negative person. This is for someone newly diagnosed today, if they have access to treatment. This is not quite as good if you already have other health complications, or for people who were diagnosed 10 or 20 years ago. But even with complications, treated HIV is not the driving force for health problems in the short or even medium term.

But you are right that other studies report higher rates of some cancers in HIV positive compared to HIV negative people. But this information needs to be read bearing a few things in mind.

The first is that these tend to mainly be cancers that are either related to other viral infections (for example, hepatitis C for liver complications) or related to lifestyle factors (smoking, diet, exercise etc) which HIV positive people as a group have higher risk factors than HIV negative people as a group. So higher percentages of HIV positive people smoke cigarettes and drink alcohol etc.

The second is that the studies usually report results using something called ‘relative risks”.

So it can be worrying to read that HIV positive people might have, for example. twice the risk of getting a certain cancer, or even 10, 20 or 30 times the risk. But from an individual perspective you also need to know the ‘absolute risk’. This is the actual risk of something happening, not just in relation to another group of people. I think you will find that the absolute risks in the same studies are nearly always very low.

So you might read that a risk is 5 times the risk if you are HIV positive – or more alarmingly 500% higher (which is the same figure in a different way). But the absolute risk might only be 1 in 10,000 (0.01%) for an HIV negative person and 5 in 10,000 (0.05%) for an HIV positive person.  These absolute risks are the real risk to you, and you probably take higher risks every day when you cross the road.

The other way that increased rates of some cancers are reported is in terms of incidence. This is how many people are newly diagnosed each year. So for some HIV-related cancers these rate are rising, even with treatment. But these figures need to be interpreted realising that the total number of HIV positive people is increasing.

One explanation for this is that more people are diagnosed every year, half of who may be diagnosed late when HIV is already advanced. Secondly, and perhaps more importantly, treatment means that people are being kept alive and growing into old age. We are living long enough to be able to have the same complications as HIV negative people. And cancer is predominantly an age-related illness. The highest risk for most cancers is age.

This means that the health advice for the general population is just as important if you are HIV positive.

The lifestyle changes than can reduce these risks are important – if you smoke try to quit, if you drink or use drugs, use them in moderation, eat a nutritious balanced diet that includes fresh vegetables and reduced red meat, fried food, refined sugar and salt. Keep or become active physically and mentally, reduce stress and be happy to make the most of life.

I am not minimising the importance of any of the studies you have read. There are some aspects of our care which will need more careful monitoring as we get older. But the picture is much brighter than the research has left you with and I hope this puts some of those studies into perspective.