Endometrial cancer after combined hormone replacement therapy

Objective: It has been suggested that exposure to relatively high levels of unopposed estrogen is a risk factor for endometrial cancer. Combined therapy of estrogen with cyclic progestagen was therefore highly recommended for menopausal women with an intact uterus. Methods: The cases of two postmenopausal women who developed endometrial cancer after taking continuous sequential HRT for 15 months are reported. Both were without bleeding for more than 2 years and presented with a normal vaginal ultrasound. They had severe menopausal symptoms and asked for HRT. Results: After 15 months irregular bleeding occurred and a hysterectomy was performed. The pathohistological finding in both cases was endometrial cancer. As we measured the serum estradiol levels 4 h after tablet ingestion supraphysiologic values ranging between 418 and 442 pg/ml were found. Conclusion: Our report strengthens the evidence that supraphysiologic estradiol levels despite combination with cyclic progestagen therapy, increase the risk of endometrial cancer.