Oestradiol measurement during fulvestrant treatment for breast cancer
Menée à partir d'échantillons sériques prélevés sur 10 patientes atteintes d'un cancer du sein de stade avancé traité par fulvestrant, sur 16 patientes ménopausées atteintes d'un cancer du sein non traité (âge médian : 50 ans) et sur 44 témoins non malades (âge médian : 35 ans), cette étude analyse l'effet du fulvestrant sur la sensibilité et la spécificité de deux tests immunologiques mesurant le niveau d'œstradiol
Biochemical evaluation of menopausal status is used to inform treatment decisions, including clinical trial eligibility in women with oestrogen receptor positive breast cancer. However, fulvestrant may interfere with oestradiol immunoassays and confound accurate assessment in this context. We conducted a service evaluation of two immunoassays and an LC-MS/MS assay to determine the extent of the interference. Serum oestradiol levels were analysed by two immunoassays (Siemens Centaur XP and Abbott Architect) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). Immunoassay gave higher serum oestradiol results than LC-MS/MS at low concentrations, with improved analytical sensitivity demonstrated by LC-MS/MS. Cross-reactivity of fulvestrant was observed for each immunoassay. We have shown that two commonly used immunoassays do not demonstrate the required sensitivity or specificity for the measurement of oestradiol in a breast cancer population. For patients receiving fulvestrant, spurious results may be generated that could impact treatment decisions. LC-MS/MS is recommended in this setting.
British Journal of Cancer , résumé, 2019