A 52-year-old woman presents to the clinic with severe menopausal symptoms, including frequent hot flashes, night sweats, difficulty sleeping, irritability, and decreased concentration. She also reports significant vaginal dryness, causing discomfort during intercourse. Her last menstrual period was 15 months ago. She is currently receiving treatment for active breast cancer. She does not smoke and exercises regularly. Her family history is significant for cardiovascular disease. On physical examination, her vital signs are temperature is 99 °F, heart rate is 78 beats/min, blood pressure is 148/98 mm Hg, respirations are 19 breaths/min, and oxygen saturation is 97% on room air and her body mass index (BMI) is 24 kg/m². Pelvic examination reveals mild atrophy of the vaginal mucosa. A bone density scan performed six months ago shows osteopenia, with a T-score of -2.2 at the lumbar spine.Which of the following is an absolute contraindication to hormone replacement therapy (HRT) for this patient?