Posting for all who might benefit...
For months I had episodes of burning pain in lower outside quartrant of left breast. Then a mammogram revealed rapid increase in microcalcifications in that same area, and a biopsy was recommended. Web search led to a study (small sample) in which 100% of those with rapid increase in microcalcifications had DCIS (stage 0 breast cancer) or other breast cancer. I knew that even though it was a small study, with numbers like 100%, it's important to pay attention.
Biopsy revealed estrogen negative DCIS (thank God for mammograms). After I obtained and read the path report I saw that the margins were not good (should be 1 centimeter or more). There had also been a cyst in the left breast and cells within it were highly abnormal. Although an MRI was unable to detect problems, after much additional research I concluded that my left breast was in a melt-down.
I opted for a bilateral mastectomy, as I could not tolerate the risk of doing less. Only after I had elected the bilateral mastectomy was I advised that the group that tends to make that choice under such circumstances is female doctors. Radiation would have been standard treatment.
After the mastectomy, the pathology results confirmed that the DCIS was pervasive throughout the left breast, and it was on the move, with cancerization of lobules. Radiation would not have covered a large enough area to address the affected cells in the left breast. It had been a setup for what would have been called a relapse. The right breast had cells that are thought to be the precursors of cancer.
Be very careful. It is extremely easy to underestimate the seriousness of what may be happening at a cellular level.