How many chemotherapy cycles before we can tell whether it is working or not? (fec protocol, stage iii breast cancer)

Pre or post?: If you get it before surgery to shrink the tumor, you can usually see a change after 2 or 3, sometimes even with just one. If you are getting it after the surgery (adjuvant) to keep it from coming back, then there is no way you can tell short term if it did the job. Only time will tell if the tumor relapses or not. Good luck either way and best regards.

Dr Estape agreed