The DietCompLyf study: A prospective cohort study of breast cancer survival and phytoestrogen consumption


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Ruth Swann1, Annie Perkins1, Louiza Velentzis2, Cristian Ciria3, Susan Dutton3, Angela Mulligan4, Jayne Woodside5, Marie Cantwell5, Anthony Leathem6, Claire Robertson1, Miriam Dwek1
1University of Westminster, London, UK, 2Cancer Council New South Wales, Sydney, Australia, 3University of Oxford, Oxford, UK, 4University of Cambridge, Cambridge, UK, 5Queen’s University Belfast, Belfast, UK, 6University College London, London, UK

Background

Breast cancer survival rates vary geographically in part reflecting variations in the diet and lifestyle of different populations. The DietCompLyf study is the largest prospective observational study to date to examine the relationship between diet and lifestyle and breast cancer recurrence and survival rates of patients in the UK.

Method

3,159 women with grade I-III breast cancer were recruited onto the study 9-15 months post-diagnosis. Recruitment took place between 1997 and 2010 from 56 hospitals across the UK. Clinico-pathology, diet, lifestyle, general health and quality of life is documented annually for up to 5 years. Blood and urine samples enable biomarker, nutrigenomic and validation studies. The characteristics of the cohort at recruitment and their reported pre-diagnosis dietary intake of foodstuffs with oestrogen-like properties (phytoestrogens: isoflavones and lignans; from the EPIC-Norfolk food frequency questionnaire) have been assessed.

Results

By descriptor, the majority of patients were post-menopausal (65%), with a grade II (46%), oestrogen receptor positive (82%) tumour, less than 20 mm diameter (50%), and lymph node negative (62%). The median follow-up is 58 months from diagnosis. Return rates for questionnaires at recruitment was at least 85% and almost all patients (≥94%) contributed biological samples. Multivariate analysis has shown isoflavone intakes to be higher in younger patients, non-smokers, those who had breast-fed and taken supplements (p<0.05). Lignan intakes were higher in older patients, ex-smokers, those who had breast-fed, taken supplements, had a lower BMI at diagnosis, lower age at menarche and were nulliparous (p<0.05).

Conclusion

A significant inverse association has emerged between pre-diagnosis phytoestrogen consumption and possession of breast cancer risk factors. The data from DietCompLyf will continue to provide the necessary evidence base on which to test dietary and lifestyle recommendations for breast cancer patients, the overall aim of which is to reduce breast cancer recurrence rates.