This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wedrén, S. Articles by Weiderpass, E. Search for Related Content PubMed PubMed Citation Articles by Wedrén, S. Articles by Weiderpass, E.

Associations between Androgen and Vitamin D Receptor Microsatellites and Postmenopausal Breast Cancer

¹ Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden; ² Department of Medical Sciences, Uppsala University, Uppsala, Sweden; ³ Swedish Medical Products Agency, Uppsala, Sweden; ⁴ Department of Medicine, Dartmouth Medical School, Hanover, New Hampshire; ⁵ Department of Etiological Research, The Cancer Registry of Norway, Oslo, Norway; and ⁶ Samfundet Folkhalsan, Helsinki, Finland

Requests for reprints: Elisabete Weiderpass, Department of Etiological Research, The Cancer Registry of Norway, 0310 Oslo, Norway. Phone: 35-840-845-3406; Fax: 47-22-45-13-70. E-mail: elisabete.weiderpass{at}kreftregisteret.no

We investigated the association between polymorphism in the androgen receptor (AR) and vitamin D receptor (VDR) genes and breast cancer risk in a large population-based case-control study of genetically homogenous Swedish women. We successfully determined both AR CAG_n and VDR A_n genotype in 1,502 women with invasive breast cancer and in 1,510 control women. We did not find any associations between AR or VDR microsatellite lengths and breast cancer when we used a priori determined cutoffs (21 or 22 repeats for AR and 18 or 19 for VDR) to define long and short alleles. There was statistically significant interaction between VDR genotype and parity, such that women with two short alleles had a halved risk for breast cancer, irrespective of parity, compared with nulliparous women with two long alleles. Homozygosity for the long VDR allele was associated with a more advanced clinical stage at diagnosis. In exploratory analyses, we determined cutoffs based on visual inspection of distributions of allele lengths among cases and controls and found that women carrying two alleles with <20 AR CAG_n repeats had an increased risk for breast cancer, odds ratio of 1.67 (95% confidence interval, 1.17-2.38), compared with those with two alleles with 20 repeats. Women carrying two VDR alleles with <21 A_n were also at an increased risk, odds ratio of 1.26 (95% confidence interval, 1.04-1.51). Our data do not support major roles for AR or VDR polymorphism as breast cancer risk factors. However, we did find an interaction between VDR genotype and parity that remains to be corroborated. (Cancer Epidemiol Biomarkers Prev 2007;16(9):1775–83)