We’re launching two reports today for people living with and beyond breast cancer and living with and beyond colorectal cancer. These are really bringing together our work looking at the role of diet, nutrition, physical activity and body weight on long-term survival for these groups.

What is the content of this report and what are the recommendations?

The reports really are aiming to bring together the latest research. Our collaborators at Imperial College, London, have undertaken extensive systematic reviews on these topics, so really looking at how diet, nutrition, physical activity and body weight influence outcomes after a diagnosis of colorectal cancer and breast cancer and also for breast cancer how physical activity impacts on quality of life.

So the reports are bringing together the findings from that research with the judgements from our expert panel. So we have a group of experts we work with who make an independent assessment of the strength of that evidence and from that our experts are able to make either recommendations or guidance for people on how to improve their health and also make recommendations for future research.

What are some of the main guidelines?

Really the main aim of this work is to provide some practical information for people and for health professionals working with people. We know that people want information about what they should eat and how active they should be in order to improve their long-term health after a cancer diagnosis.

So from this work, although on the whole we weren’t able to make strong recommendations because of the problems with the study quality, we were able to work with experts and bring together the evidence with expert opinion in order to make some practical guidance.

The guidance that we were able to make for both cancers is that people should, as much as they can, follow World Cancer Research Fund and AICR’s recommendations for cancer prevention. So we have ten recommendations for cancer prevention and the information that we found supported that. But in terms of specific guidance for patients after a diagnosis, for breast cancer we’re making a recommendation that people are physically active and this is largely based on the evidence from our review on quality of life where we found strong evidence that increasing physical activity improves quality of life and it may also improve health outcomes but that evidence wasn’t as strong.

Also for breast cancer there was some evidence that having a higher fibre intake improves health outcomes. So we’re making guidance for people to increase their intake of dietary fibre. We didn’t find evidence for soy really being harmful, which is reassuring for people. So although we’re not making a specific recommendation or guidance for people to increase their soy intake, certainly for people consuming soy we’re saying that’s fine to carry on doing that.

So those were the main guidance for breast cancer. For colorectal cancer we’re making guidance that people should consider increasing their physical activity, should consider increasing their intake of whole grains. But, of course, being mindful of the types of treatment they’ve had. So really that should be done with caution and done, of course, gradually and ideally under the supervision of a health professional.

Also we had some limited evidence that higher intake of coffee, both decaffeinated and caffeinated coffee was associated with improved health outcomes for people after colorectal cancer and also a lower intake of sugary drinks. So certainly for people to consider consuming less sugary drinks.

What are the recommendations for future research?

The panel had some difficulties in making recommendations for this group. The strength of the evidence was quite limited. Despite this being a growing area and we know it’s a really important area with improved survival after cancers, the research is very much in its infancy compared to that of incidence. So there was limited evidence but also limitations in the quality of the evidence. That meant that the panel, on the whole, was not able to make strong recommendations for people.

So we worked with experts to develop a new process whereby we’re making the most of more limited evidence but alongside that making very strong recommendations for future research. So one of the issues was that the characteristics of samples were not well characterised. So, for example, the types of treatment that people had had, the stage of the disease at diagnosis and other characteristics. That meant that it was difficult for the panel to interpret the evidence, so it was hard to know whether associations observed were causal.

So one of the recommendations for future research is that characteristics of samples are much better characterised, that there are better assessments of diet, nutrition and body weight and body composition, but also more diverse populations. The research was very much limited on high income countries and not very diverse samples.