ICR - The Institute of Cancer Research: Global Foundation

We all want to know what factors in our lives and in our families’ lives may cause cancer to develop and how cancer can, in some cases, be prevented. In its most basic form, genetic epidemiology sets out to identify genetic factors that contribute to susceptibility to cancer in people.

The Institute of Cancer Research was the world’s first organization to establish that the underlying basic cause of all cancer was damage to a person’s DNA. How and why DNA damage occurs can be a result of many combinations of genetic and/or environmental events. This is where epidemiology steps in.

Cancer epidemiology is the study of the distribution and causes of cancer in human populations.

There are a large number of sites of the body at which cancer can occur, and microscopically different cell types of cancer. For certain types of cancer, such as lung cancer, a considerable amount is known about causes, mainly because of past epidemiological research, but for others the causes are largely unknown.

One of the ICR’s most celebrated advances was in identifying the first suspected biological link between smoking and lung cancer back in the 1930s. The link in humans was shown in the 1950s by epidemiological studies in Britain and the US, and paved the way for scientists and doctors to apply this knowledge in advising the public about prevention of cancer.

Epidemiological research has identified many other causes and risk factors associated with cancer, such as the raised risks of particular cancers in people who work with asbestos, the increased risk in those who consume large quantities of alcohol and the effects of ionising radiation. This has allowed prevention in the workplace, and for people to be more informed about lifestyle choices that can reduce cancer risk. However, for a large proportion of cancers, the causes remain unknown.

Advances in technology in recent years have allowed genetic epidemiologists to start to address the identification of genes that affect a person’s chance of developing a particular cancer.

In many cases, the causes of cancer appear to be a combination of genetic, environmental, and lifestyle influences. Unravelling these factors is a complex process. If we can find the genetic factors, we can then offer comprehensive advice to cancer patients on the risks for family members and what to do to reduce that risk.

To explore the links between genetic vulnerability, lifestyle and environment requires large-scale population studies over a number of years. The studies that will make the biggest difference have thousands or even tens of thousands of people entered. The ICR has a particular advantage of conducting such research in the UK with its relatively stable population and a National Health Service. This makes it far easier to undertake epidemiological studies that track people’s health throughout their life.

In partnership with Breakthrough Breast Cancer, ICR scientists are undertaking the largest study in the UK targeted on the causation of breast cancer, which has recruited more than 100,000 women and will continue for at least 40 years. This follows on from research at ICR that uncovered the BRCA2 genetic mutation, which can be passed down from parent to child and produces a high risk of breast and ovarian cancers.