Hormone replacement therapy with continuous estrogen and seven days of added progestin per month result in endometrial adenocarcinoma

CASE REPORT: The 73-year-old female patient presented with intermittent postmenopausal vaginal bleeding for about 20 years. She is 155 cm tall and 41 kg in weight. She visited a gynecologist for advice about perimenopausal syndrome 20 years ago. The doctor suggested continuous premarin 0.625mg daily and added  provera  seven days per month. She did not visit other doctors  about the prescription, but bought drugs in pharmacy for about 20 years. Intermittent vaginal bleeding was found, but she considered it as usual progesterone withdrawal effects. She came to our clinic because the vaginal bleeding became heavier than before for several days. An enlarged uterus was noted on pelvic examination . An ultrasound revealed thickened hyperechoic endometrial mass, measured 29x38x22mm in size. The definition of endometrial-myometrial junction is not clear. The diagnosis of endometrial adenocarcinoma was confirmed after an endometrial sampling. DISCUSION: Unoppsed estrogen promotes mitotic growth of endometrium and is highly related to endometrial neoplasia. Progestin protects endometrium by reducing cellular receptors for estrogen and induction of traget cell enzymes that convert estradiol to estrone sulfate. What is the minimal monthly progestin exposure to protect the endometrium? Some had  suggested at least 10 days’ duration of added progestin. In our case, the patient under HRT with continuous estrogen and 7 days of added progestin per month seems at high risk of endometrial carcinoma.