Answer:
Dense breasts are associated with an increased risk of developing breast cancer, and also make it more difficult for a radiologist to see a small cancer in the midst of that dense normal breast tissue.
After lumpectomy and radiation, there is often a scar on mammogram that is more dense than surrounding breast. The reading radiologist relies on shrinkage or stability of that denser scar, over time, to say that it is not recurrent breast cancer.
The fact that you are so long after treatment makes recurrence unlikely, but not impossible. So, go do the extra views, during which the radiologist is likely to be present, and ask him or her what is seen. Sometimes ultrasound, and even MRI, can be useful when there is a question about a mammogram. So ask about those tests also.
After lumpectomy and radiation, there is often a scar on mammogram that is more dense than surrounding breast. The reading radiologist relies on shrinkage or stability of that denser scar, over time, to say that it is not recurrent breast cancer.
The fact that you are so long after treatment makes recurrence unlikely, but not impossible. So, go do the extra views, during which the radiologist is likely to be present, and ask him or her what is seen. Sometimes ultrasound, and even MRI, can be useful when there is a question about a mammogram. So ask about those tests also.