Breast Cancer Update for Surgeons, Issue 1, 2017 (Video Program)Benefits and limitations of the DCIS Score
3:03 minutes.
TRANSCRIPTION:
DR LOVE: We were talking about the genomic assays for invasive cancer, including the 21-gene Recurrence Score, but there’s also a genomic assay for DCIS. It doesn’t seem like it’s been used anywhere near as much. Can you talk about what we know about that? DR KING: Yes. So it’s an important question. So the DCIS score, again, you mentioned a genomic assay for DCIS, very similar to the 21-gene Recurrence Score. The genes aren’t exactly the same, but certainly the concept is the same, where the score separates women into low, intermediate or high risk. Not for distant recurrence now, which the invasive test does, but low, intermediate or high risk for in-breast recurrence. And that in-breast recurrence, we know, can be either DCIS again or it can be invasive cancer. I think the limitation of the DCIS Score, although it does provide us that prognostic information — so it may be a useful tool for counseling women as to what their risk of recurrence is, the DCIS Score does not tell us anything predictive about response to therapy. So, for example, even if a woman has a low DCIS Score with the genomic test, it doesn’t tell us that she won’t benefit from radiation. And again, that’s really the value of or one of the biggest values of the score that we use in invasive cancer is that a low score in invasive cancer tells us the women will not benefit from chemotherapy, that we can just use hormonal therapy and feel confident. If we had that extra piece of information from the DCIS Score, if we could say, “Okay. You fall into the low-risk category, and we know that radiation is not going to help you,” then I think it would have greater traction in clinical practice than what we’re seeing now. But what it does tell us now is certainly it can be useful as a decision-making tool if a patient is not quite sure whether she wants radiation therapy. If the score were to come back quite high, demonstrating that she has a high risk of in-breast recurrence, maybe that would help her in making her decision. But there’s again not as much discrimination between an intermediate and a high score in the DCIS test as there is in the invasive test. So it really gives us 2 categories, a quote-unquote low risk, which is not as low as some might want. So the low-risk score at 10 years, the risk of cancer recurring in the breast is about 12%. So for some women, 12% doesn’t sound too low. The high-risk score, the risk of cancer recurring in the breast is on the order of 25% to 30%. That’s certainly high for many women. But again, the piece of information that’s missing from that test is who will benefit from radiation. And so until we get that piece, we are still in this quandary of treating everybody or trying to use clinical factors to weed out who maybe doesn’t need radiation. |