My Sister Is 62 Years Old, Had Breast Cancer 10

My sister is 62 years old, had breast cancer 10 years ago with a lumpectomy and radiation and no recurrence. She had a colonoscopy on Monday 10/31. Today she advised she was having vaginal bleeding. Dr sent her for internal ultrasound today. She said it was very painful when she had internal ultrasound. She has no children and had a tubal pregnancy in early twenties. MD said she was high risk for uterine cancer due to no kids. Any opinion? She is my only sister and I am very upset.