Detailed definition
Endometrial cancer is the most common gynecologic malignancy in the United States. Type I (endometrioid) is estrogen-driven, accounts for approximately 80% of cases, and is associated with chronic estrogen excess from obesity, anovulation (PCOS), unopposed estrogen therapy, tamoxifen, and other sources. Type II (serous, clear cell) is less estrogen-dependent. Properly combined HRT — estrogen plus continuous or cyclic progestogen — does not increase endometrial cancer risk over baseline. Unopposed estrogen in women with a uterus increases endometrial cancer risk approximately 2–10 fold depending on dose and duration. Postmenopausal bleeding is a key warning sign and should always be evaluated, typically with transvaginal ultrasound (endometrial thickness >4 mm warrants biopsy) and often endometrial biopsy.
Why it matters in menopause
The progestogen requirement for women with a uterus on systemic estrogen is non-negotiable. Any postmenopausal bleeding, including breakthrough bleeding on HRT, requires evaluation rather than reassurance.
Related terms
Sources
External references: Wikipedia.