In my understanding ADH is considered a benign finding (but also sometimes referred to as a pre-cancer in my experience). It is a risk factor that elevates chances of future breast cancer to fifteen percent. Eight years after an ADH finding on excisional biopsy/lumpectomy I had a new breast cancer develop in the same area - part of that unlucky fifteen. I was followed with mammograms in those in between years, but not with MRIs. Today protocols should include both. DCIS is considered the earliest form of breast cancer (Mayo clinic site) but not invasive.