A Nested Case-Control Study of Luteinizing Hormone Variants and Risk of Breast Cancer.
Abstract
An immunological variant of luteinizing hormone (LH) dependent on two point mutations in the gene of the LH beta-subunit has increased in vitro bioactivity and is detectable in serum with immunofluorometric assays (IFMA). The variant occurs with a frequency of 5-25% in the general population. The altered bioactivity and kinetics of the LH variant are accompanied by changes in LH action and by increased stimulation of the ovarian stromal cells and may be followed by increased production of ovarian testosterone and androstenedione and their estrogen metabolites estradiol and estrone. The study takes advantage of an on-going prospective cohort study of hormones and breast cancer. Serum samples from cohort subjects are being assayed for testosterone, androstenedione, estrone, estrone sulfate, estradiol and SHBG as part of a case-control study nested within the cohort (497 cases and 1,384 controls). In year 1 of the project, we completed a preliminary analysis of the alleged association between breast cancer (cases identified before 1995) and the presence of the variant LH. Preliminary results suggest that a positive association may be present in young, pre-menopausal women. Laboratory analyses of LH variant will be completed in year 2 and the relationship between variant and serum levels of steroid hormones will be examined in the final year.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1998
- Accession Number
- ADA369250
Entities
People
- Paolo G. Toniolo
Organizations
- New York University