Estrogen Levels Linked to Breast Cancer Gene Expression
Study finds expression of estrogen-dependent genes correlated with plasma estrogen
TUESDAY, Feb. 2 (HealthDay News) -- Plasma estrogen levels are correlated with the expression of estrogen-dependent genes in estrogen receptor (ER)-positive breast cancers, according to a study published online Feb. 1 in the Journal of Clinical Oncology.
Anita K. Dunbier, Ph.D., from the Royal Marsden Hospital in London, and colleagues measured pretreatment plasma estradiol levels and profiled pretreatment gene expression in tumor tissue from 104 premenopausal women with primary ER-positive breast cancer treated with neoadjuvant anastrozole.
The researchers found a significant association between the expression of estrogen-responsive genes and gene sets and plasma estradiol levels. In particular, 27 percent of the average expression of four key estrogen-responsive genes could be explained by plasma estradiol, while 37 percent could be explained by a standardized mean of plasma estradiol levels and ER transcript levels. The results were confirmed in an independent set of 73 ER-positive breast tumors. Both plasma estradiol and the standardized mean of estradiol levels and ER transcript levels were significantly correlated with a surrogate marker of clinical outcome.
"Plasma estradiol levels are significantly associated with gene expression of ER-positive breast cancers and should be considered in future genomic studies of ER-positive breast cancer," Dunbier and colleagues conclude.
Several authors reported financial and consulting relationships with pharmaceutical companies.