Today we're going to talk about why you need radiation after a lumpectomy for invasive breast cancer. For cancer, many of my patients come in and ask, “Hey, the surgeon said they got it all. Why do I need radiation?” That's a great question, because it doesn't make sense.
If your surgeon “got it all” the time of surgery, why would you need radiation to the breast? I’d like to give a little bit of a history of breast cancer, just to understand where we got this information about why you need radiation, and why we do what we do today.
They first started doing lumpectomies back in like the late 1970s. Before that, we just did mastectomies on everyone. When they started doing lumpectomies, they found that 40% of the women had recurrences in the breast. What that means is that 40% of the time, there were cells that were left behind in the breast that eventually grew. This is even with negative margins. So for patients who had lumpectomies, the margins were all clear, and then the cancer came back 40% of the time. 40% is obviously not an acceptable recurrence rate. So that's when they started using radiation in early 1980s, to sterilize any cells that may be left after lumpectomy.
It turns out that we still do this today. The typical treatment after a lumpectomy is that you have radiation to the whole breast. And the idea is that you're sterilizing any of those cancer cells that may be left behind to reduce the risk of recurrence. The risk of recurrence is reduced from 40%, which we talked about lumpectomy alone, down to less than 10%. The actual percentage depends on your tumor, the receptors, the grade of the tumor, whether it has spread to the lymph nodes, and your age. There are multiple factors that will determine your exact risk of recurrence in the breast, but it's somewhere less than 10%.
That's why you need radiation after a lumpectomy. There are some caveats to this. Some women who are older than 70 may choose to forego radiation in lieu of anti-estrogen therapy, and I'll do a separate video on that, but that is an exception. And then also there is a type of radiation that is just to the tumor bed, and some women qualify for that. Those are small tumors, women are over 50, no lymph node involvement, and widely clear margins at least three millimeters. We'll go over that as well in a separate video.
Hopefully that answers your questions. Please like this video and put comments below if you have other questions, I'd love to answer them. Thanks so much!
Pictured: Audry, diagnosed at age 67, lumpectomy and partial breast irradiation