It was not caught early. It had already metastasized (gone into a lymph node.) It was good she went in when she did, but not going to the doctor for 10 years was pretty stupid.
The only references to ten years were that "Maybe five, eight, even ten years ago, the first bad cell split inside me, secretly." and "Even though I was ten years younger than the time they say you need to start," She went to the doctor soon after noticing the "funny stiffness," not ten years later.