Egistrozole is a drug intended for use in the treatment of breast cancer that occurs in postmenopausal women. It contains anastrazole - a substance that inhibits the synthesis of estrogen in tissues, thanks to which the division of estrogen-dependent breast cancer cells is inhibited and the lesion does not grow. The Etruzil used by you earlier contains letrozole - a substance from the same group as anastrazole, i.e. an aromatase inhibitor that inhibits estrogen synthesis. The mechanism of action of these drugs is the same. It is impossible to predict whether anastrazole will be better tolerated by your body than letrozole. This is an individual matter. I enclose helpful materials: https://www.gdziepolek.pl/produkty/26328/egistrozol-tabletki-powlekane/ulotka https://www.gdziepolek.pl/produkty/27899/etruzil-tabletki-powlekane/ulotka https://www.gdziepolek.pl/kategorie/rak-piersi