Measurement of Estradiol—Challenges Ahead

In their recent Endocrine Society position statement on the measurement of estradiol, Rosner et al (1) provide a good overview of the current status of estradiol assays in the context of their clinical and research applications. The position statement includes both published data and the expert opinions of the authors, and it is long overdue because estradiol assay methods that lack accuracy and precision are being used in many clinical and research settings (2, 3). Problems of inaccuracy are particularly found when measuring the low estradiol levels commonly seen in prepubertal children, postmenopausal women, and men, as well as in patients treated with aromatase inhibitors. The position statement outlines the many challenges associated with standardizing estradiol measurements using mass spectrometry assay methodology. The purpose of the present commentary is to point out: 1) the relevant populations in which estradiol measurements are critical; and 2) the problematic ranges of these measurements.