For what it is worth, I have been on HRT for many years with no tumor regrowth since my 2011 surgical removal of my AN.
Right MVD for trigeminal neuralgia, 1994, Pittsburgh, PA
Left retrosigmoid 2.6 cm AN removal, February, 2008, Duke U
Tumor regrew to 1.3 cm in February, 2011
Translab AN removal, May, 2011 at HEI, Friedman & Schwartz
Oticon Ponto Pro abutment implant at same time; processor added August, 2011