Genetic Epidemiology Group

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. Recent studies of both candidate genes and the entire human genome have begun to uncover inherited genetic variants that are associated with breast cancer risk.

The long-term aims of our genetic studies are:

1. To identify and validate low-penetrance breast cancer susceptibility alleles and understand the functional consequences of these variants
2. To determine their prevalence and contribution to overall cancer incidence in the population, and use this information to calculate personal risk estimates by combining genotype and family history data 
3. To identify genetic variants that interact with known breast cancer risk factors and discover variants that influence clinical efficacy and toxicity of drugs in patients undergoing chemotherapy.

We are involved in several ongoing collections of blood samples and questionnaire data for genetic research on breast cancer including the Breakthrough Generations Study; the British Breast Cancer Study, a national collection of bilateral breast cancer cases, their relatives and friends (as unaffected controls), the Breakthrough Male Breast Cancer Study, and TACT, a phase III clinical trial of docetaxel as adjuvant chemotherapy.

We are pursuing several complementary approaches to identifying and characterizing genetic variants that are associated with predisposition to breast cancer and variants that influence clinical outcomes in sub-groups of breast cancer patients: analysis of individual Single Nucleotide Polymorphisms (SNPs); high throughput analysis of SNPs in groups 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.