<prompt> A 40 year old lady with breast cancer has undergone MRM and is on Tamoxifen for 1 year. She now has presents with bleeding per vaginum 4-5 times. What is the probable cause:Bleeding disorderEndometrial cancerOvarian cancerCervical cancer  <response>: Ans. b Endometrial cancerRef: KDT 6th ed. 304-5 Tamoxifen is selective estrogen receptor modulator SERM. It is having agonistic activity at uterine endometrium.Action of TamoxifenAgonistic activityAntagonistic activityUterus: causes proliferation of endometrium - can cause vaginal bleeding as seen in the caseBreast CABone: decrease resorptionBlood vesselsLipid profile: decrease LDL without affecting HDL - decrease risk of CAD 