ASCO 2011 Annual Meeting, 3—7 June 2011, Chicago

Links between cancer and weight, ethnic origin or social status

Dr Jennifer Ligibel – Dana-Farber Cancer Institute, Boston, USA

So this was a session, it was an educational session so not presenting specific studies but an overview of this field, looking at the relationship between weight and cancer outcomes. So for people who have been diagnosed with cancer, does their weight make a difference? I presented an overview of some of the hundreds of studies that have looked at the relationship between how much a person weighs and what happens with their cancer. There are hundreds of studies, many of them in breast cancer and Dr Rock’s study in breast cancer is the culmination of this work, that show that women who are overweight when they are diagnosed with breast cancer seem to have a higher rate of recurrence compared to leaner women. We don’t really know why that is and it’s not clear whether this is actually due to weight or due to other things – could they be eating better, exercising more, doing other things? So there’s a lot of work going on right now that’s trying to figure out, looking at this observational data, seeing this relationship between weight and breast cancer and other cancer prognosis, trying to figure out what’s the biology that connects those. Dr Kaaks from the University of Germany in Heidelberg talked a lot about biology, biologic mechanisms, hormones that are changed in obese patients and then Dr Rock talked about her study, which is one of the first large studies to try to change weight in patients with breast or other cancers, to look at how that makes people feel and hopefully, eventually, we’ll have some real information about how changing weight affects cancer outcomes in breast and other cancers. 

So where’s your money? Exercise, insulin growth factor receptors? Give me the Dana-Farber view.

The Dana-Farber view, I’ve done a lot of studies in exercise and I think that there is very consistent evidence that exercise is an important part of survivorship for breast cancer patients and colon cancer patients and prostate patients. I think weight is also important, it’s probably more important in breast cancer than in some of the other malignancies. It’s hard to separate out weight and exercise since those two things really go together. I think what we really want to be able to show is that changing some of these factors after someone is diagnosed makes a difference. I think that a lot of patients are diagnosed with cancer, they get all these treatments, they have side effects, they go through all this and then they come to their oncologist and they say, “What can I do to help my overall outcome?” And it would be a wonderful thing if we could tell people exercise, eat better and it’s really going to make a difference, not only in how you feel but whether your cancer comes back or not.

It would seem to be that that advice should be given irrespective of the outcome of any trials. I was interested in the link to social deprivation, because I’m very interested in social deprivation and there is an even bigger obesity problem, a link to social deprivation, certainly in Europe and, I suspect, in some of the ethnic minorities in Europe it’s an issue and it’s certainly an issue for some of the ethnic minorities in the US. Is anybody looking at that?

There are groups that are looking at those populations. We know that there are differences in tumour types, in breast cancer at least, in some ethnic minorities compared to Caucasian patients. In African-Americans there are higher rates of more aggressive breast cancers and there are also higher rates of obesity. So there are groups that are looking at some of these observational relationships; there haven’t been as many studies looking at interventions in these minority populations and it’s something that’s really important because we know that, in the US at least, a lot of our ethnic minorities are under-served, they don’t get the same type of healthcare and they’re also not participating in these clinical trials. I think it’s very important because the biology may be different in some of these groups.

And they’re not getting the messages either because our messages do not disseminate through to the people who really need to hear them most. I’m convinced there is something other than the social deprivation side of things and there is a biological issue because a study I was involved in, where I come from in Glasgow in Scotland, we found that social deprivation was an independent prognostic factor for outcome of breast cancer management when patients from the same general practice were put through exactly the same pipeline. They went through the same breast cancer service, they got treated by the same surgeons, they got the same protocols, all of them were on protocols, but still the difference in outcome was bigger, in the same ballpark, as the negative influence of Tamoxifen. So the Tamoxifen was fighting against the postcode, or the zip code, and I think there is a real issue there and I’m not sure how to tackle it. But however you tackle it, you’ve still got to do something about it in terms of intervention. What other interventions, apart from cognitive psychology, are being looked at?

There are many, many intervention studies that are going on across the US and across Europe looking at changing different types of behaviour. There are many physical activity interventions that focus on group-based walking programmes. Dr Rock’s intervention is beautiful and it’s very well designed, it’s also very labour intensive so there have been a lot of programmes that are looking at interventions that have cancer survivors reaching out to other survivors. There is an investigator named Bernadine Pinto at Brown who is developing a great programme where she trains cancer survivors to set up support groups and exercise groups and give information to other survivors. There are a lot of programmes that are being done to look at telephone-based dissemination of weight loss programmes and exercise programmes to try to find something that we can make generalizable to big groups of people. Ultimately if we can show that these things make a difference in cancer outcomes, in the States we’ll be able to involve insurance companies and set up platforms for this. Many patients who have diabetes have a diabetes coach that calls them; if we could have a lifestyle coach, a weight loss coach, an exercise coach that helped patients with these types of behaviours it would make a huge difference. 

I’d love to think that the United Nations summit in September, which is bringing in the non-communicable diseases, the diabetes people and the cardiac people and the cancer people, would come to the conclusion that this is something important that needs to be done. I’m convinced already that it needs to be done. Whether the United Nations putting their money behind that, they’ve no money, putting their authority behind that, would make an impact, I don’t know. Would this be one way to go because it’s a global issue, this?

I think that’s a really interesting thought to get this more on the table. The issues of obesity and physical activity for many years were thought to really affect patients in the States and not worldwide, but I think we’re seeing that more and more the types of eating patterns, weight patterns and activity patterns that we’ve had for a long time here are unfortunately spreading across the globe. So I think that that would be a really good step to make people more aware of this. There has been a lot of focus on access to care and ways to get many of these very expensive drugs distributed, and I think that’s really important, but messages like this, I think have really been ignored and this could be something that helps a lot of patients in a very cost-effective way.

It’s going to be much cheaper and for less well-off countries it will be the only option they have.

And rather than having side effects like nausea and hair loss, the side effects are lower rates of heart disease and diabetes.

Absolutely. Thank you so much, Jennifer, for bringing this to our attention and we’ll do whatever we can on ecancer.tv to help you with the dissemination of this message.

Wonderful, thank you very much.