A 55-year-old woman with a history of breast cancer treated with tamoxifen for 3 years presents with postmenopausal bleeding. Transvaginal ultrasound shows an endometrial thickness of 8 mm with a heterogeneous, cystic appearance. Hysteroscopy reveals a polypoid lesion. Biopsy shows endometrioid adenocarcinoma arising in a background of tamoxifen-associated endometrial polyp. Which statement about tamoxifen-related endometrial cancer is correct?

• A Tamoxifen acts as a pure anti-estrogen on the endometrium
• B Endometrial surveillance with annual ultrasound is recommended for all tamoxifen users
• C The risk of endometrial cancer decreases with duration of tamoxifen use beyond 2 years
• D Tamoxifen exerts a weak estrogenic effect on the endometrium, increasing polyp and cancer risk ✓

Explanation

Tamoxifen is a selective estrogen receptor modulator (SERM) with anti-estrogenic effects on breast but weak estrogenic agonist effects on the endometrium, stimulating endometrial proliferation, polyp formation, and increasing cancer risk 2-3 fold. Routine screening is not recommended by ACOG for asymptomatic tamoxifen users; investigation is only for abnormal bleeding. Risk increases with duration of use beyond 2 years, not decreases.

Reference: Bailey and Love's Short Practice of Surgery, 28th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.