Julia White, MD, professor of radiation oncology at The Ohio State University Comprehensive Cancer Center, discussed tailored local therapy treatments for patients with breast cancer who receive neoadjuvant chemotherapy and get a complete pathologic response at the San Antonio Breast Cancer Symposium, held December 10-14, in San Antonio, Texas.
The focus of this presentation was to talk about (whether) we tailor our local therapy treatments for when patients receive neoadjuvant chemotherapy and they get a complete pathologic response. As you know, there’s quite a bit of data that women who have a complete pathologic response to neoadjuvant chemotherapy, particularly in the triple negative and the HER2-positive subtypes have a much better prognosis in terms of improved overall outcomes. That’s really been important for designing trials for systemic therapies. This talk was more focused on how does this affect our local treatments, radiation and surgery specifically. When you look at the data that comes from retrospectively looking at local regional recurrence in clinical trials, it’s evident that local regional recurrences after treatment are lower in women who get a pathologically complete response then those who do not, regardless of whether they start off with a higher stage node positive breast cancer or a smaller node negative breast cancer. Response to chemotherapy provides a lower risk of local regional recurrence, so that helps us have opportunities in local regional therapy to tailor treatment.
One of the things that’s been really great in when we do surgery first is, we’re able to use sentinel node biopsy to avoid axillary dissection in patients. It’s been a challenge to figure out, how do we use sentinel node biopsy in the neoadjuvant setting after a patient presents with positive nodes, but then she gets down staged to a clinically node negative. Can we use sentinel node biopsy to identify who’s truly negative in that axil and perhaps avoid the toxicities of an axil node dissection? And so, I think what’s happened recently is we have 4 prospective trials with really great information that help identify how best we can use sentinel node biopsy after receiving neoadjuvant chemotherapy. And altogether these trials tell us that if you pick your patients well in terms of making sure they’re biopsied up front, confirming their node positivity, they go through neoadjuvant chemotherapy, you use dual tracer to identify the sentinel node, and you get more than two sentinel nodes harvested, that the likelihood is that you’re going to have a false negative rate below 10%. In particularly, the trials also demonstrate that if you can clip the sentinel node, if you biopsy ahead of time and put a clip in and then can retrieve it afterwards, your false negative rate will be less than 10%. As well as making sure that patients who have positive individual tumor cells after neoadjuvant chemotherapy are considered positive, which is different than in the adjuvant setting where we consider positive individual tumor cells negative.
Doing all these things together, I think these trials help us see that you can have a low false negative rate to make sentinel node biopsy a reasonable first step for women who come with positive nodes, become clinically node negative after neoadjuvant chemotherapy. And ultimately a certain percentage of those women will be able to avoid axillary node dissection, which I think will help reduce toxicity long term.