My Treatment Approach: Applying Evidence to Clinical Practice to Improve Outcomes in Differentiated Thyroid Cancer - Episode 9
Shared insight on active surveillance practices for patients with radioiodine-refractory DTC and how disease factors play into selection of therapy at time of recurrence.
Marcia Brose, MD: Lori, you already touched on this, but maybe you can tell us concisely what your triggers are for switching from active surveillance to treatment. Do you have a little list in your head? How do you do it?
Lori Wirth, MD: That period of active surveillance or disease monitoring is very helpful in order to establish the nature of the disease because there is such a wide variation in the natural history of iodine-refractory DTC [differentiated thyroid cancer]. Some patients can progress very slowly over time, and those patients probably would benefit from a long period, or as long a period as possible, of disease monitoring and holding off on initiating a TKI [tyrosine kinase inhibitor] like lenvatinib. When this patient had disease that was worrisome from the get-go, that period of disease monitoring was tremendously beneficial for us to know exactly what it is we’re dealing with. Just like the lung biopsy told us exactly what we were dealing with, so we don’t have to second guess ourselves here. It’s hard to define what this is, but there is a clinically meaningful disease progression. I do think that a tiny bit of disease progression isn’t a big deal. If you see new lung [metastases] cropping up here and there, that’s meaningful even if they’re not huge chunky lung metastases.
The other thing that Bruce mentioned is the performance status. If patients have a performance status of 0, they’re perfectly fine, that’s great. In the SELECT trial, because of the eligibility criteria, generally when patients had a performance status of 1 vs 0, it was probably because of their thyroid cancer and being symptomatic from their thyroid cancer. When we looked at how patients with a performance status of 0 vs 1 did in the SELECT trial, the performance status of 0 patients did better and had better overall survival as well. We definitely do not want to wait until patients have symptoms or are nearly symptomatic from their disease before you hit that sweet spot of starting.
Marcia Brose, MD: I would totally second everything that you’re saying. I would add another thing that I consider as well, and it comes down to the importance of looking at the scans yourself, because you are getting a sense of what you’re seeing and the pace of it if you look at the nodules vs just reading somebody else’s measurement, No. 1, but also the location. I’ve had patients who’ve only had maybe a centimeter and a half lymph node here or there in the mediastinum, and it may not have been something to trigger me right away, but I could see the narrowing starting to happen. That would tell me this isn’t going to be a good behavior even though it’s not that big because it’s going to knock off the right upper lobe in this case for this one patient. Another area that I worry about particularly is when patients start having those beads on a string that are along the fissures, either the major fissures or they have them along the pleural surface, because that many times the scans underestimate the tumor burden in those cases. I’ve even had a thoracic surgeon who told me that the lung was completed coated with cancer, it’s just that it didn’t show up.
In addition to now thinking about the size and the performance status, we also have to consider the location of the disease. I also would definitely support and second your point about getting this biopsy. Literally, just last week I had a patient at the time of progression who had a new liver metastasis, and I went ahead and biopsied it because I wanted to get the genetics on it and I hadn’t gotten genetics on the patient, and she had metastatic colon cancer. This is a common enough cancer that we always have to consider, and I’ve also diagnosed non–small lung cancer, so we always have to make sure we know what we’re dealing with.
Bruce Robinson, MD: The other thing I’d add too, Marcia, you were talking about looking at scans. Often in selected patients, it’s quite good to have the patients look at the scan too because when they do see a response, they are encouraged, and the psychological benefit of that, if of course they do respond, is great. If they don’t, the opposite is true, but it does help patients to visualize things.
Lori Wirth, MD: That’s a lot of fun to do with the patients too, to celebrate those responses.
Marcia Brose, MD: I agree, and I have a patient who comes in and she’s always despondent and has a list of a hundred things that she’s upset about. Then I show her. I always keep track in my notes of when their starting date was, and I’ll pull up the scan from their starting date and where they are now because maybe from time to time, it’s not that big a difference, but in a year and a half, there’s been a huge difference. Then she shuts up and sits down, and she’s like, “Yeah, I’m not going to change anything.”
Bruce Robinson, MD:Yes, it’s good. I agree.
Marcia Brose, MD: It convinces them. Bruce, you continue to treat your patients and follow them, correct?
Bruce Robinson, MD: That’s correct.
Marcia Brose, MD: When you’re following them, how often are you seeing them?
Bruce Robinson, MD:Following the initiation of therapy, I keep in phone contact with them. Then I’d like to see them generally a month later because it’s often at that time that you need to be at least beginning to think about some sort of dose adjustment, but at the same time you’re often trying to encourage these people to maintain the initial 24-mg dose. Once they’ve become stable, their blood pressure is well controlled, they seem to have settled down to a dose that they can tolerate, and you’ve got evidence their disease is controlled, I drop the follow-up back to every 3 months, and find that for most people that’s OK. During the COVID-19 pandemic, of course, we’ve had to do a lot of this remotely, telehealth consultations, and that’s been much more challenging because it hasn’t been as easy to have patients scanned as it was prior to COVID-19. And we’ve managed, is the bottom line, and I often wonder whether in retrospect we perhaps were a little overzealous with our frequency of follow-up in scanning. But it only takes 1 patient to have a bad outcome because of an adverse effect wasn’t properly managed, and you certainly then challenge yourself and think that these people need to be seen a bit more often. In essence, it’s monthly for the first 3 or 4 months, and then I drop it back to every 3 months.
Marcia Brose, MD: I do something similar. I probably go to every 2 months until a year, and then I go to every 3, but again, I give them more of a leash depending on how they’re tolerating it. If they are swimming right through it, I’ll go to every 3 months sooner.
Transcript edited for clarity.