@jmab I also had lumpectomy and 5 days of radiation.
Twice. First on left breast and four years later the right breast. Like you, I wonder if the second was unrelated to the first. And this after colon cancer four years before the first breast cancer. Lucky that all were small and treatable but I worry about another one. Every four years is so odd - so another three years will be four years since the last. I am now 87 and learned that I have a
hereditary pathogenic cancer gene. I am urging my daughter and siblings to get tested. My mom had two cancers. I am otherwise healthy and grateful for my days.