Management of DTC in Clinical Practice

Lori J. Wirth, MD: One of things I’ve wondered is, as an endocrinologist, what do you think about the optimal timing of therapy? I’ve always wondered, because as a medical oncologist, we give people chemotherapy. We do phase 1 trials in which we give higher and higher doses of drugs until you get to the maximum tolerated dose. You might have to back down a bit. There’s a comfort level that medical oncologists have with therapies that have toxicities. I’ve always wondered if the lens of a medical oncologist is skewed a little 1 way vs the lens that an endocrinologist brings to the thought process.

Jennifer Sipos, MD: It’s a very important point. I would imagine we also fall along a spectrum. I am a pure endocrinologist. I see cancer patients, but I don’t administer these drugs. There are endocrinologists who just treat thyroid cancer patients and administer these drugs. Then there are folks like you who are oncologists and administer these drugs. I suspect we map out nicely along that spectrum in terms of our viewpoints of these agents.

My view of these drugs is that they’re associated with toxicities. My lens is tinted toward, “OK, I can watch this person a little while longer.” I have to be really mindful to loop my oncologist in. We like to try to bring in the oncologists ideally 6 to 12 months prior to when we think they’re going to need a drug so that they can establish that relationship. As you were saying earlier, it’s important to get to know the person, understand their disease course, and see how they individually have manifested with their disease. That happens organically over time if allowed. We don’t always have that opportunity to have that relationship. We don’t really want our patients to have to go straight to the oncologist, and the first thing they do is start a drug. But if they have to, they have to. 

I generally will try to follow the patients as long as I can. Once I’m starting to think, “OK, this is not going to respond to another treatment. Their disease is starting to progress a little faster,” or “They’re getting a little more tumor burden, and they’re going to need a drug within 6 to 12 months,” I’ll start talking to the oncologist. I’ll say, “Hey, I want to send this person to you.” 

Even before that point, I’ll have conversations with the patient. They’re very generic conversations. I may say, “We’re going to need a drug at some point. We have a number of drugs available, and just in the past 5 years, we’ve gotten several FDA approvals. The landscape is changing very rapidly, which is a good thing.” I just talk in general terms about how these things work and their mechanism of action. I provide a very general framework by saying, “This is what cancer is. It’s a mutation in a pathway, and these drugs target that specific mutation.” Once I’m starting to have those conversations, I’ll order genomic testing to see if there’s going to be an agent that could potentially be useful for that patient or a more specific drug. If there’s not an actionable mutation, then we’ll use the angiogenic medications at our institution. That also helps us if we’re starting to think about whether this patient will be a candidate for a clinical trial as well.

Genomic testing happens early in someone who I think will eventually need a drug. Before or while I’m having those conversations, I’m also evaluating the patient for their candidacy for a drug. Do they have a good performance status? If this is someone who has some other comorbid disease that I’m worried could pose a threat to their vitality in the next 6 to 12 months, then I’m not going to be necessarily pushing that conversation as much.

I have younger patients who have familial disease, and they had to watch a loved one on one of these drugs who didn’t have necessarily a great experience with it. They may say, “No, I don’t really want to use 1 of those agents.” It’s important from my perspective that we have conversations about these drugs. I discuss what they can expect in terms of adverse effects, what the disease response is going to be, and their wishes for end-of-life concerns. If they’re in their 80s and they say, “I don’t want to be on those drugs. I want to enjoy a good quality of life,” then I can respect that. I see that as my job to explore those conversations with the patients. If they’re not sure, then my approach is to just refer them on to oncology for more careful discussion. Hearing it from another person can give them much more information sometimes.

Lori J. Wirth, MD: Yes, it sounds like a setting of the stage.

Jennifer Sipos, MD: Yes, exactly.

Lori J. Wirth, MD: When we consider the idea of passing a baton in a relay race, you just don’t toss a baton and they’re on their way. You hand it, and you run along with them.

Jennifer Sipos, MD: Or run alongside.

Lori J. Wirth, MD: You’re in the race together.

Jennifer Sipos, MD: Exactly.

Transcript edited for clarity.