A westernised diet increases the risk of breast, prostate and colorectal cancers. Prospective studies

suggest a common mediator: high circulating IGF-I concentrations. Recent data suggested IGF-I is also

associated with cervical cancer. The large inter-individual differences in IGF-I concentrations are thought to

be partly heritable, but also strongly dependent upon nutrition. We suggest that interactions between

heritable factors and nutrition determine an individual's IGF-I concentration and subsequent cancer risk.

We propose a nested case-control study within ALSPAC. To date there have been 400 incident cases of

cancer in the ALSPAC mothers. Dietary information and blood samples have been collected from mothers

(in pregnancy) prior to the cancer presentation and from their children at age 7-8 years. We will measure

circulating concentrations of IGF-I, IGF-II and IGFBP-3 in (a) mothers who have developed breast or

cervical cancer (b) control mothers without cancer and (c) their children. We will examine whether

IGF-measures were prospectively associated with the development of cancer. Furthermore we will use

the disease-free mother-child pairs to examine associations between IGF-measures in mothers and their offspring

and the extent to which these may be due to common patterns of diet, other shared environmental exposures

or may be inherited.