Is your MIL on HRT? My mom was on HRT for 6 months when she started having lump issues. Within a year, she had a radical bilat mastectomy. When I pressed the surgeon as to why this happened, the surgeon said "family history, genetics, blah blah blah." I told the surgeon no other female on my mom's side has ever had breast CA. Surgeon said, "Must have been the HRT then. Studies indicate that causes breast CA."
There you have it....
"Because he tried to kill me. Now I gotta return the favor." Bas Rutten