Risks and adverse effects Risks with estrogen therapy or combined estrogen / progestogen therapy include Endometrial cancer, mainly if women who have a uterus take estrogen without a progestogen Breast cancer Deep venous thrombosis Pulmonary embolism Stroke Coronary artery disease Dementia Gallbladder disease Stress urinary incontinence The risk of endometrial cancer is higher in women who have a uterus and are given unopposed estrogen therapy.