Do our Recommendations reduce cancer risk?

Grant title: Adherence to the WCRF/AICR Cancer Prevention Recommendations and cancer risk and survival in the UK
Grant awarded: November 2020

World Cancer Research Fund’s Cancer Prevention Recommendations are a major step towards reducing cancer risk by improving lifestyle. However, it is still not clear how best to measure adherence to those Recommendations or the extent to which better adherence lowers cancer risk and improves survival after cancer diagnosis. In this project, we will address these issues using data for about half a million people who are participants in UK Biobank. My colleagues and I are delighted to receive support in this work from Wereld Kanker Onderzoek Fonds. We hope that our findings will help to guide lifestyle recommendations and public health policies for the general population, and to improve length and quality of life for cancer survivors.

– Prof John Mathers

Background

Lifestyle factors including body fatness, diet and physical activity influence risk of getting cancer and may also be linked to chances of surviving after cancer diagnosis.

In 2007, World Cancer Research Fund and American Institute for Cancer Research published 10 lifestyle-based Cancer Prevention Recommendations including maintaining a healthy body weight, and eating little red and processed meats. Studies have found relationships between adherence to these recommendations and the risk of, and death from, different cancers.

In 2018, these Recommendations were updated, and, in 2019, a standardised scoring system was developed which determines how closely individuals adhere to these lifestyle targets. However, when this project started, relationships between this new “adherence score” and cancer risk and survival were unknown.

Aims and objectives

The primary aims of this study were to investigate whether the adherence score predicts:

risk of developing cancer
survival after cancer diagnosis

in the UK.

Methods

First, we carried out a systematic review of the evidence from the scientific literature reporting on associations between adherence score and risk of cancer.

Then we used data from UK Biobank – a large study to which over half a million men and women aged between 37 and 73 years, across the UK, were recruited between 2006 and 2010. Investigators collected detailed information about the participants, including diet, body fatness and physical activity. Cancers that have occurred in people who took part in UK Biobank have already been identified.

We used these data to investigate whether the adherence score (calculated in a standardised way using data collected when the participants joined UK Biobank) predicts:

risk of developing cancer
survival after cancer diagnosis

We also developed an abbreviated score that allowed us to investigate data from a larger number of UK Biobank participants.

Results

The systematic review of the literature showed that, in 18 studies carried out in several countries, higher adherence score was linked with lower risk of developing cancer overall and with lower risk of breast, bowel and lung cancer. Findings from UK Biobank confirmed the lower cancer risk among those with higher scores and lower risk of several common cancers including cancer of the:

Among participants who did not have cancer when joining UK Biobank, but who were diagnosed subsequently with a cancer, we found that higher abbreviated score was linked with reduced risk of death.

Conclusions

This project provides strong evidence that higher adherence to the Cancer Prevention Recommendations is associated with lower risk of several common cancers.

Impact

This evidence underpins policies and interventions to improve lifestyle behaviours in the UK and globally. In addition, for the first time, they have shown that higher adherence also reduces the risk of mortality in those diagnosed with cancer. This is important new evidence for cancer survivors and for those developing policies to improve health and longevity after a cancer diagnosis.