This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological oncology, Subject name: Gynaecology & Obstetrics
Tamoxifen predisposes to : 
Select and explain. 
A. Endometrial cancer, B. Ovarian cancer, C. Cervical cancer, D. Vaginal cancer
A: Endometrial cancer
Answer: A: Endometrial cancer 
Explanation: In Breast Cancer although tamoxifen improves the survival period, it causes endometrial hyperplasia and cancer, and requires regular monitoring with ultrasound study of endometrium and endometrial biopsy. Reference: Shaw's Textbook of Gynaecology 16th edition page no 540