Androgen receptor genotypes predict response to endocrine treatment in breast cancer patients.
Author
Summary, in English
Background:The androgen receptor (AR) is frequently expressed in breast cancers. The AR genotype may affect disease-free survival and response to endocrine therapy.Methods:In all, 634 women undergoing breast cancer surgery between 2002 and 2008 were followed until 30 June 2010. Six haplotype-tagging single-nucleotide polymorphisms in the AR, and the resulting AR diplotypes, were examined in relation to breast cancer patient characteristics, tumour characteristics, disease-free survival, and response to endocrine treatment.Results:Five common AR diplotypes were found. Seventeen rare variants were combined into a composite group. The resulting six AR diplotype groups were clustered into two subgroups, groups A (n=128) and B (n=499), with three diplotypes in each. Patients in group B had larger total breast volume (P=0.024), higher body mass index (BMI) (P=0.050), more axillary lymph node involvement (P(trend)=0.020), and higher histological grade (P(trend)=0.031). There were 59 breast cancer events in the 569 patients with invasive cancers and no preoperative treatment. Patients in group B also had shorter disease-free survival (P=0.037) than patients in group A. Among patients in group B with oestrogen receptor α positive tumours, tamoxifen (TAM) treatment was associated with longer disease-free survival (P=0.008), while treatment with aromatase inhibitors (AIs) was not (P=0.94). Response to endocrine treatment could not be predicted based on BMI, suggesting that the effect of AR diplotypes went beyond that of a higher BMI.Conclusion:A marker for a group of patients who responded to TAM, but not to AIs, was identified. If this finding is confirmed, AR genotyping may provide useful information for selection of endocrine treatment of breast cancer patients.British Journal of Cancer advance online publication, 27 October 2011; doi:10.1038/bjc.2011.441 www.bjcancer.com.
Department/s
- Breastcancer-genetics
- Surgery (Lund)
- Epidemiology and pharmacogenetics
- BioCARE: Biomarkers in Cancer Medicine improving Health Care, Education and Innovation
Publishing year
2011
Language
English
Pages
1676-1683
Publication/Series
British Journal of Cancer
Volume
105
Issue
11
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Document type
Journal article
Publisher
Nature Publishing Group
Topic
- Cancer and Oncology
Status
Published
Research group
- Epidemiology and pharmacogenetics
ISBN/ISSN/Other
- ISSN: 1532-1827