Estradiol E2 (LC.MS), therapy with fulvestrant

Serum, 1ml

Fulvestrant is an anti-oestrogen with an estradiol comparable structure and binds onto the oestrogen receptors of the cell surfaces of tumour cells, instead of oestrogen. It is employed to treat women experiencing the natural or synthetically induced –menopause suffering from local, advanced or mestasising oestrogen receptor-positive mammary carcinomas.. In such situations, Fulvestrant blocks the effect of oestrogen, reduces the receptor count on the surface of tumour cells and thus inhibits tumour growth.
As a result of the cross reactivity of Fulvestrant with conventional immunological testing for the ascertainment of estradiol levels, any control of the estradiol in breast cancer patients during this therapy, is not possible. Erroneously enhighten-ed parameters can thus lead to false interpreta- tions and a mistaken discontinuance of the medication.
In such situations, the ascertainment of estradiol by the application of mass spectrometry (LC-MS/MS) can be an incidental alternative; and, as a result of the high degree of selectivity and specificity of mass spectrometry, such a method of determination does not affect the existence of Fulvestrant.