Dear Canapoli: In 2008 My wife had non-TNBC lumpectomy(twice) surgery in 2008, but the surgeon had to do it twice, because it had "lobular" (ILC) meaning... Infiltrating Lobular Cancer., it was a situation where the surgeon's incision did not get it all, and she had a tiny(.3mm)( "point 3 millimeters in a 3 millimeter lymph node) cancer in one lymph node. We had no idea in 2008 that this cancer might show up later, and in 2015 ........ I just want you to know, my wife says today, she wishes she had both breasts removed.
In 2015 my wife got TNBC in her other breast, much worse. Of course, there is no way to calculate if her 2008 cancer changed, genetically, but please be aware, any chemotherapy and radiation cause "mutations" in the DNA.
The doctors she has now are at UCSan Diego/Moores Cancer Center, they have done a bunch of genetic testing, which we are very thankful for....all cases are not the same,
if you DO NOT have any cancer in the lymph nodes, that would surely weigh on your decision, I'm sure there are members here that have opinions on what surgery is right for you.
My opinion, from what I have gone through with my wife, is if it's TNBC , even in one breast, my opinion, as a husband, is mastectomy, for my wife was the safest thing to do.
I would ask your doctors if your are Triple Negative Breast Cancer, after a lumpectomy, what are the chances of a local-recurrance, they call it a "regional" perhaps, of the cancer coming back