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Epidemiology & Cancer round-table discussion

Wednesday 10 November, 2021

The work of epidemiologist is something we’ve been hearing a lot about over the past few months. Having epidemiologists within our organisation has been beneficial for understanding more about the surveillance and reporting of COVID-19.

The work of epidemiologists at Cancer Council centres around looking at data to discover more about the causes of cancer, and how we can better prevent it.

In October, 70 guests joined CEO Todd Harper, Professor Roger Milne and Associate Professor Brigid Lynch at a virtual round-table discussion delving into some of the most commonly asked questions about epidemiology and cancer.

Questions posed by the audience covered a wide range of topics including the history of epidemiology, the translation of epidemiological research and recent research findings. Here are just some of these questions and responses.

What is epidemiology as a field of study and how long has it existed?

Epidemiology literally translates from Greek as “the study of what is upon the people”. We use the term epidemiology to mean the study of diseases or other health-related events in populations. The idea that environment and host factors (behaviours) might cause disease was suggested by Hippocrates around 400 B.C. The first publication of patterns of birth, death and disease was by John Graunt in the 1600’s, however, it is John Snow who is considered the father of epidemiology. In the mid-1800 he mapped out deaths from cholera in the Golden Square area in London and identified the source of the outbreak as a public water pump.

How does epidemiology relate to cancer and why is epidemiology so important to reducing the impact of cancer?

Cancer epidemiology looks at the who, when, where and why of cancer. Descriptive epidemiology describes the patterns not only of disease, but also of risk factors for disease. This enables us to describe the problem that cancer presents, and to track our progress in promoting healthier lifestyles for prevention, reducing incidence and improving survival.

Central to cancer epidemiology is the aim of identifying why people develop cancer and what they can do to prevent it. Cancer epidemiology also aims to identify what people can do to improve survival after a cancer diagnosis.

It is cancer epidemiology that has shown that smoking, obesity and alcohol all cause several types of cancer and that physical activity can prevent cancer and improve survival for cancer patients. We can’t do clinical trials on risk factors like this, so we rely on the tools of epidemiology to provide high-quality evidence.

How does the Cancer Epidemiology Division seek to understand who gets cancer and why?

We conduct large-scale studies to identify genetic, demographic and behavioural risk factors for cancer.

Through cohort studies like Health2020 and the ABC Study we capture information about the health and behavioural activities of cohort participants and collect biological samples including saliva, blood and even faeces.

We then follow cohort participants over several decades, contacting them periodically to update information about their behaviours and exposures, measuring genetic and other markers in their samples and tracking who develops cancer over time.

We later analyse the data we’ve collected and assess differences between those who do and don’t develop cancer. We then draw conclusions about risk factors, causes and confounders. We use these research findings to inform prevention campaigns and strategies.

What role does physical activity play in terms of cancer risk, and health outcomes for cancer survivors?

Physical activity is important for maintaining good health, and we know it is a protective factor for a number of cancers. Recent research that our Cancer Epidemiology Division is involved in suggests that the risk of up to 15 different cancers can be reduced with physical activity. We’re working with international collaborators on estimating how many cancers could be prevented if all Australian adults were physically active.

We ran a trial a couple of years ago to test whether wearable technology could help women who have had breast cancer become more active. We’re now applying for funding to scale-up this intervention and deliver it to women living in regional and remote areas, where it is much harder to access in-person exercise training.