AACR Annual Meeting 2013

Racial disparities in cancer outcomes

Dr Camille Ragin – Fox Chase Cancer Center, Philadelphia, USA

Cancer health disparities really have to do with difference with respect to the incidence or the rate of diagnosis of disease. And disparities, when we talk about disparities we’re really comparing groups of people, so there can be racial disparities where there are differences by race or gender disparities where there are differences by gender, either in the rates of cancer diagnosis or with respect to outcome from disease once diagnosis is made. My main interest has to do with racial disparities and my focus has been to really begin to look at the burden of cancer in populations of African ancestry , so whether it’s African-American or African-Caribbean populations or African populations.

The major disparities are primarily for men is prostate cancer, particular for women breast cancer is an issue as well, particularly with response to outcome. And, depending on the geographic region from which the population resides, if you look at developing countries, for example, in the Caribbean or in Africa, there seems to be a tendency for disparities related to infection-associated cancer. So, for example, HPV related cancer, cervical cancer, those rates tend to be higher in those populations; liver cancer also tends to be higher to some degree in Africa and the Caribbean as well.

What are the reasons for this?

I think for the most part we all know that access to care and screening are primary reasons, poor socio-economic status, because obviously that will affect prevention activities. And obviously that makes sense in developing countries where resources are low. But there are other reasons as well and one of the things that I’m very interested in looking at, myself and other colleagues, are to look at the biological basis for disease and to see how that contributes to disparity. So that’s really the focus that we have.

What about large collaborative studies?

Many years ago I put together a cancer consortium called the African Caribbean Cancer Consortium and it really is a collaborative network and all of the members of this consortium primarily focus their research on cancer in populations of African ancestry. We have a US network, a number of members all over the country are part of this group, and we also have a network in the Caribbean, several countries are represented, and then we have a network in Africa. And the idea here is to allow… to provide a forum for us as a team to work through trans-disciplinary methods to be able to address cancer across these regions, to be able to collect information in a standardised way to begin to really ask the questions and find some answers related to these disparities for various cancers.

We’re still in that capacity building phase; it’s been a couple of years since we’ve been together and we have done some studies, small studies, really to address feasibility but also hypothesis development. And we’re at a point now where we’re trying to begin to plan for these larger multi-centred efforts. But it takes time, having a large group of persons working together, it takes a lot of time to build these collaborative relationships. And it also takes time with respect to making sure that all of us as researchers across these three different regions are at a level playing field because we have to recognise that, particularly in these developing countries, there are brilliant scientists that are there but limited resources to work with what they need to be able to accomplish. And that’s the reason why it has taken us such a long time to build capacity. And we feel that we’re at that point where we’re ready now to begin to launch these multi-centred studies.

In prostate cancer, what can be done to reduce the disparity?

I think, number one, screening is important. Obviously we all know the importance of early detection and screening and that in itself would serve some benefit. Also being more aware of the risk factors that we know of: healthy eating, eating fresh fruits and vegetables, physical exercise, those are all important behaviours that we can actually have control over. So being able to address our health in that way will help to reduce your risk and that’s one of the things that we try to advocate in the community when we work.

Are there differences between African-Americans and Africans?

Actually when you look at the statistics there is a geographic variation with respect to incidents of, say for example, prostate cancer. The rates are much, much higher in African-American men and then a little lower in Caribbean men and then lowest in African men. And I think for the most part we’re still trying to understand that geographic variation. There could be a number of reasons; one of those reasons could be under-reporting because what you find is that in these developing countries the screening prevalence may be lower and so we’re not identifying the cases and then ultimately we’re assuming that the rates are lower. So it’s quite possible that under-reporting could be accounting for this variation but it still does not rule out the other possibilities and those are some of the questions that we’re trying to address.

You’re also interested in infections types of cancers?

HPV, yes, human papilloma virus, it’s really the primary cause for cervical cancer and it also is a primary cause for oropharyngeal cancers, cancers of the throat and the tonsils. So yes, it’s a sexually transmitted virus and there are actually a number of HPV types that contribute to cancer. And, of course, we already know that there are two vaccines that exist that will prevent the infections of the two most common types, HPV 16 and 18, and those two types really account for about 70% of all cervical cancers worldwide.

Is the cost of the vaccine a problem?

It certainly is and that poses to be a challenge and hopefully that will change because I think one of the most important things we have to remember is that with such an important breakthrough in medicine we really have to think about how we can utilise this tool to address the burden in the populations that need it. And so cost definitely has to be addressed and I’m sure it is being addressed.

Is it available publicly in Africa?

I think for the most part it is available. I do know of some countries that are implementing the vaccine but of course there are variations and it all depends on the resources available and how broadly these programmes are being conducted. But at least we know that there are efforts being made to do so, so that’s promising.