Overview
Cancer epidemiology is a scientific discipline that aims to identify environmental, lifestyle and genetic factors that may be associated with an increased, or a decreased, susceptibility to the disease.
This discipline has made a substantial contribution to our current knowledge on the causes of breast cancer. Classical epidemiological studies have identified several reproductive (e.g. early age at menarche, late age at first birth, low parity, and late age at menopause) and lifestyle factors (e.g. increased alcohol consumption, overweight after menopause, and use of oral contraceptives and HRT) that are associated with a raised risk of developing breast cancer. More recently studies of candidate genes and studies of the whole genome have begun to identify genetic variants that are associated with breast cancer risk.
Research aims
The long-term aims of our genetic studies are:
(i) to identify and validate low-penetrance breast cancer susceptibility alleles
(ii) to understand the functional consequences of these variants
(iii) to determine their prevalence and contribution to overall cancer incidence in the population, and hence
(iv) to calculate personal risk estimates by combining genotype and family history data.
We have several ongoing collections of blood samples and questionnaire data for genetic research on breast cancer including a national collection of bilateral breast cancer cases, their relatives and friends (as unaffected controls), and a national collection of unselected breast cancer cases and friends. We are pursuing several complementary approaches to gene finding through association studies of cases and controls: analysis of individual Single Nucleotide Polymorphisms; high throughput analysis of SNPs in large numbers of candidate genes; genome-wide searches for genetic variants and analysis of SNPs in relation to intermediate phenotypes such as mammographic density, plasma levels of growth factors and urinary hormone measurements. Correlating genotype data with levels of such quantitative markers of susceptibility may be an efficient alternative to case-control analysis for gene discovery.
Our projects are an example of the close collaboration between research charities that are concerned about breast cancer. Most of our direct funding is from Cancer Research UK but we also have funding from Breast Cancer Campaign and all our laboratory work takes place in the Breakthrough Research Centre, specifically so that we can benefit from all the diverse scientific research that is carried out in this centre. We collaborate closely with other Breakthrough scientists, with colleagues at the Institute of Cancer Research and we are part of a larger epidemiology and genetics group lead by Professor Julian Peto and Professor Isabel dos Santos Silva at the London School of Hygiene and Tropical Medicine.
