BCC 2021 | Should chemotherapy be used in post-menopausal patients with low genomic risk HR+ breast cancer?

So the question of giving chemotherapy to patients who have lower-risk hormone receptor-positive breast cancer continues to be controversial. Really because we’re trying to treat patients for cure and we’re balancing the concern for patients who we know have a risk of recurrence with incurable cancer, against giving treatment that has toxicities both in the short- and the long-term setting. And if that toxicity is not going to result in an improved outcome, you don’t want to give the treatment. Trying to understand that is difficult. If we look at the criteria from MINDACT, TAILORx, RxPONDER in these patients who have one to three positive axillary nodes or node-negative hormone receptor-positive disease, there is a division in our thinking based on whether the patient is in menopause or not. And in post-menopausal women, we now have quite a bit of data that suggests that if you have a low risk signature or a recurrence score of 25 or lower, that chemotherapy doesn’t benefit these patients.

And that’s actually, I think a really interesting question. In general, at St. Gallen, the voting group agreed that there are patients with a low risk score who meet these criteria, one to three positive node-negative disease, low genomic scores, should generally not receive chemotherapy. But the caveat to that is that we want to still take the clinical characteristics, the clinico-pathologic characteristics into account. So the voting was interesting. I think that what we generally believe, and this was true for a fifth of the voting group, is that if you have higher-risk criteria, so the amount of data for patients who have three nodes versus one to two is relatively small, so people would consider chemotherapy in that group. If they have other high risk features, so for example, a very large tumor, a recurrent score on the higher side, we just don’t know.

And again, a fifth of the respondents felt that if you had a tumor that was greater than five centimeters or three positive nodes, that this is a situation in a post-menopausal woman where chemotherapy could be considered. It doesn’t mean you have to give it, but considered and discussed with patients. And I think it really highlights the fact that we can’t separate all of the groups. We make a one to three node criteria for saying that you have N1 nodes, but for some patients, I mean, a single node of 2.5 millimeters is not the same as having three nodes where the biggest node is three centimeters and you have extranodal extension and tumor and extranodal fat. I mean, these patients have a much higher risk criteria. So I think it really highlights the art of medicine.