I'm not on hormone therapy yet - still deep in chemo territory. I went through menopause last year and was "official' timewise in early January. Never had hot flushes during the day but did get night sweats for a while. About 3 weeks ago, I started getting hot flushes (and night sweats again). I reported it to the onc who reckons that although I've gone through menopause (which believe it or not, is considered to be a fairly gradual process), there's still some level of oestrogen being produced and the chemo is cutting that off abruptly. I don't know if this explanation is of any use to you but thought I'd put it out there.