Colorectal Cancer: Individualizing Treatment, Improving Outcomes - Episode 10
John L. Marshall, MD: So, if you did start with EGFR therapy in the frontline setting, what’s your maintenance option?
Johanna C. Bendell, MD: There are data, at this year’s ASCO meeting.
Cathy Eng, MD, FACP: I’ve used it as maintenance.
John L. Marshall, MD: You just keep the EGFR going? No 5-FU [fluorouracil]? No other chemotherapy? You’d just use single-agent EGFR as maintenance?
Johanna C. Bendell, MD: There’s an abstract, at this conference, looking at panitumumab—using FOLFOX/panitumumab and going to 5-FU/panitumumab as maintenance.
Cathy Eng, MD, FACP: Or you can just use single-agent anti-EGFR therapy. I think that is very reasonable.
John L. Marshall, MD: For frontline therapy, I’m giving 5-FU, oxaliplatin or irinotecan, bevacizumab. How many cycles do you do, until you stop, to maintenance? I’m so tired of 12. What is your number?
Cathy Eng, MD, FACP: I do 4 months.
John L. Marshall, MD: Four months?
Dale R. Shepard, MD, PhD, FACP: I don’t give them a defined time. It’s response versus toxicity. Everyone asks how long I am going to do this for, and I tell them that it depends on how their tumor responds and how they tolerate the treatment.
John L. Marshall, MD: Optimum response?
Cathy Eng, MD, FACP: I completely agree with that.
Michael A. Morse, MD: I think most of the responses will occur by 6 to 8 doses. If they haven’t gotten that initial response…
Dale R. Shepard, MD, PhD, FACP: But people cling to those numbers that you tell them at that very first appointment.
Cathy Eng, MD, FACP: Oh, I don’t actually tell them.
Dale R. Shepard, MD, PhD, FACP: That’s exactly why I don’t give them a number.
Johanna C. Bendell, MD: I give it for 4 to 6 months. At the 4-month scan, if they’re still shrinking and they’re not having toxicity, I…
John L. Marshall, MD: So, optimized response is sort of what I’m thinking. It’s rare to get too many responses after that. There is nothing magic about the number 12? Is everybody OK with that?
Cathy Eng, MD, FACP: Yes.
John L. Marshall, MD: Let’s talk about moving through to other lines of therapy and the incorporation of biologics. If we started, as most of us tend to, with VEGF [vascular endothelial growth factor] therapy, and I’ll give you a left-sided, RAS wild-type, BRAF wild-type patient, what is your second-line biologic of choice?
Cathy Eng, MD, FACP: I still continue with bevacizumab.
John L. Marshall, MD: Does this depend on anything? Is there a patient in whom you would give EGFR therapy to, in that setting?
Cathy Eng, MD, FACP: I usually reserve it.
John L. Marshall, MD: You hold it?
Dale R. Shepard, MD, PhD, FACP: I hold it.
Michael A. Morse, MD: Part of this is making sure that people have enough lines of therapy. The reality is, you get the most lines of therapy if you do 2 lines that have bevacizumab, currently, as opposed to going right to an anti-EGFR therapy.
Johanna C. Bendell, MD: Yes, keep going.
John L. Marshall, MD: Yes, agreed. I sort of hold the card to ask, “Do I need a response?” This is really my next response. I get my first-line response. You don’t get a lot of response in the second-line setting. I don’t know your opinions on that, but if I hold it and things are still cool, I’ve got another response card that I can play, downstream, because our subsequent lines of therapy are not so good. How about the flip side? In those rare patients, as we’ve talked about, where we did EGFR in the frontline setting, what is your biologic of choice in the second-line setting? Do you keep your EGFR therapy going through the second line? Do you switch to VEGF?
Dale R. Shepard, MD, PhD, FACP: Yes.
John L. Marshall, MD: Is there a VEGF of choice? Does anybody use bevacizumab?
Dale R. Shepard, MD, PhD, FACP: Bevacizumab.
Cathy Eng, MD, FACP: Bevacizumab.
John L. Marshall, MD: Is there any reason to change? Not really? So, everybody stays with that, even though there are 3 approved options in this space?
Cathy Eng, MD, FACP: Correct, there are.
John L. Marshall, MD: We tend to plug along with that.
Transcript Edited for Clarity