Objective-Hydroxysteroid-dehydrogenase-17b (HSD17b) genes control the last step in estrogen biosynthesis. The isoenzymes HSD17b2 and HSD17b4 in the uterus preferentially catalyze the conversion of estradiol, the most potent and active form of estrogen, to estrone, the inactive form of estrogen. Endometrial adenocarcinoma is linked to excessive exposure to estrogens. We hypothesized that single nucleotide polymorphisms (SNPs) in genes HSD17b2 and HSD17b4 may alter the enzyme activity, estradiol levels and risk of disease.Methods-Pairwise tag SNPs were selected from the HapMap Caucasian database to capture all known common (minor allele frequency>0.05) genetic variation with a correlation of at least 0.80. Forty-eight SNPs were genotyped in the case-control studies nested within the Nurses' Health Study (NHS) (cases=544, controls=1296) and the Women's Health Study (WHS) (cases=130, controls=389). The associations with endometrial cancer were examined using conditional logistic regression to estimate odds ratio and 95% confidence intervals adjusted for known risk factors. Results from the two studies were pooled using fixed effects models. We additionally investigated Correspondence to: Stalo Karageorgi, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA. Fax: +617-432-1722, skarageo@hsph.harvard.edu.
Conflict of interest statementThe authors declare that there are no conflicts of interest.
Author contributionsAll authors contributed to this study and approved the enclosed final manuscript. S.K. performed all analyses, assisted with study design, and prepared the manuscript; M.McG. assisted with study design, data analysis, and manuscript editing; and I.L., J.B, P.K, and I.DV. were involved in all stages of this project, including obtaining funding, study design, data collection, statistical support, and manuscript editing.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. whether SNPs are predictive of plasma estradiol and estrone levels in the NHS using linear regression.
NIH Public AccessResults-Four intronic SNPs were significantly associated with endometrial cancer risk (p-value <0.05). After adjustment for multiple testing, we did not observe any significant associations between SNPs and endometrial cancer risk or plasma hormone levels.Conclusions-This is the first study to comprehensively evaluate variation in HSD17b2 and HSD17b4 in relation to endometrial cancer risk. Our findings suggest that variation in HSD17b2 and HSD17b4 does not substantially influence the risk of endometrial cancer in Caucasians.