gms | German Medical Science

50. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds)
12. Jahrestagung der Deutschen Arbeitsgemeinschaft für Epidemiologie (dae)

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie
Deutsche Arbeitsgemeinschaft für Epidemiologie

12. bis 15.09.2005, Freiburg im Breisgau

Dietary phytoestrogens and mammographic density – results of a pilot study

Meeting Abstract

  • Gabriele Nagel - Deutsches Krebsforschungszentrum, Heidelberg
  • Ulrich Mack - Abteilung Gyn. Radiologie, Universitätsklinkum Heidelberg, Heidelberg
  • Dietrich von Fournier - Abteilung Gyn. Radiologie, Universitätsklinkum Heidelberg, Heidelberg
  • Jakob Linseisen - dkfz, Heidelberg

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie. Deutsche Arbeitsgemeinschaft für Epidemiologie. 50. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 12. Jahrestagung der Deutschen Arbeitsgemeinschaft für Epidemiologie. Freiburg im Breisgau, 12.-15.09.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05gmds334

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/gmds2005/05gmds028.shtml

Published: September 8, 2005

© 2005 Nagel et al.
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Outline

Text

Objectives

In Asian countries, the incidence and mortality of breast cancer is lower than in Western countries. It was suggested that this could be due to the higher consumption of soy products in these countries [1]. Soy and soy products are sources of isoflavones as one class of phytoestrogens. Another class of phytoestrogens which is predominant in Western diet are lignans that occur in cereals, fruit and vegetables. High mammographic density is a well-established marker for breast cancer risk. Harvey and Bovjberg reviewed twelve studies on mammographic density and breast cancer risk and reported that breast cancer risk for dense versus the least dense areas ranges around four [2]. So far, soy intake was found to be inversely associated with breast density patterns which indicate reduced breast cancer risk. Thus, it would be of interest to determine the influence of phytoestrogens which are more common in Western diet on mammographic density. The purpose of this pilot study was to explore the feasibility of mammogram collection and measurements of mammographic density and phytoestrogens intake.

Material and Methods

The European Prospective Investigation into Cancer and Nutrition (EPIC)-Project in Heidelberg is in progress since 1994 [3]. Baseline dietary intake was obtained by means of validated food frequency questionnaires. Nutrient intake data were calculated from the food intake data by means of the German Food Composition Table BLS, Version II.3. Dietary intake of total phytoestrogens (isoflavones and lignans) was calculated based on the intake of main phytoestrogen-providing food groups and subgroups using available analytic data in the literature regarding foods of habitual European diet [4]. In addition, extensive questioning on lifestyle factors, reproductive and medical history was performed at baseline.

Within a random sample of 505 women of the cohort, those women were identified who received mammography during follow-up. Written informed consent for the collection and evaluation of the mammograms was attained. The relevant cranio-caudal mammograms were retrieved from the medical records, randomly blinded and scanned. The Wolfe classification summarizes the mammographic density according to the duct patterns in relation to breast cancer risk. Four categories were defined: N1 (lowest risk), P1 (low risk), P2 (high risk) and DY (highest risk) [5]. For the analysis DY was compared to the remaining classes (N1, P1, P2).

The SAS procedure NPAR1WAY was used to explore differences according to mammographic density.

Results

Out of the 505 women, 317 (63%) returned the questionnaire and 310 (61.4%) women provided written informed consent. Mammograms were available from 54 women.

Seven (13%) women had mammographic dense (DY) and 47 (87%) women non-dense breast patterns. Dense mammographic patterns were found in 6 women aged over 55 years and non-dense mammographic patterns in 21 women aged over 55 years. No substantial differences were found for parity, age at first full term pregnancy, smoking status and educational level.

The mean intake of carbohydrates (p-value=0.015), fibre (p-value=0.008), seeds and nuts (p-value =0.012), and soy-products (p-value=0.004) was higher in women with non-dense breast patterns. Among the phytoestrogens, high secoisolariciresinol intake was associated with non-dense breast patterns (p-value=0.043) and, in tendency, genistein intake (p-value=0.069), respectively.

Discussion

About 60% of the approached women provided written informed consent. It was feasible to select the relevant mammograms from the medical records and scan the films. Compared to women with dense mammographic patterns higher intake levels of carbohydrates, fibre, nuts, and soy products were observed in subjects with non-dense mammographic breasts. Higher secoisolariciresinol intake was found in women with non-dense mammograms. These observations indicate an influence of dietary factors on mammographic density. Further enlarged studies are needed to confirm these effects.

Acknowledgement

The authors give thanks to the volunteers for participation and the physicians for cooperation. Supported by grants from the European Community (SI2.326938) and Deutsche Krebshilfe e.V. (70-2488).


References

1.
Messina MJ, Persky V, Setchell KDR, Barnes S. Soy intake and cancer risk: a review of the in vitro and in vivo data. Nutrition and Cancer 1994;21:113-31.
2.
Harvey JA, Bovjberg VE Quantitative assessment of mammographic breast density: relationship with breast cancer risk. Radiology 2004: 1:29-41
3.
Boeing H, Wahrendorf J, Becker N. EPIC-Germany-A source for studies into diet and risk of chronic diseases. European Investigation into Cancer and Nutrition. Ann Nutr Metab. 1999;43(4):195-204. Review
4.
Linseisen J, Piller R, Hermann S, Chang-Claude J; German Case-Control Study. Dietary phytoestrogen intake and premenopausal breast cancer risk in a German case-control study. Int J Cancer. 2004 Jun 10;110(2):284-90
5.
Wolfe JN: Breast cancer parenchymal patterns as an index for developing breast cancer. Am J Roentgenol, 1976;126:1130-1139