Does Ozmpic really cause thyroid cancer? What does science actually say

For all the buzzers around Ozmpic and similar GLP-1 weight loss drugs, there are many concerns about potentially serious or long-term side effects.

Among the worst of these fears is that GLP-1 drugs can cause certain types of thyroid cancer. Risk Warn Advice for people at a higher risk, such as those with a family history of certain cancers to avoid their use.

The first medicines for GLP-1 (for type 2 diabetes) hit the market 20 years ago, however. After arriving, scientists have conducted numerous studies examining whether these drugs really cause thyroid cancer – including study published Last January in Jama Otolaryngology – Head & Neck Surgery.

In general, this study, like many, but not all studies, does not detect significant increased risk in thyroid cancer associated with the use of GLP-1 (compared to other diabetes drugs). In addition to the basic results, discoveries can also give an important clue about why some studies have found such a connection.

Gizmodo talks with study author Rosalina McCoy, an endocrinologist at the University of Maryland, about the origin of the potential connection between GLP-1 and thyroid cancer. She discussed the findings of her team and compromises involved in the launch of any new medicine, however miraculous it may sound. The next conversation is slightly edited for clarity and grammar.

Gizmodo: Why do doctors and agencies like the FDA worry about this possible risk of thyroid cancer from using GLP-1?

Rosalina McCoy: And as these drugs develop, they are also tested. This testing is done in animal models, usually rodents. In those early preclinical studies done before these drugs were ever used in humans, there was concern about what is called C -cell tumors, which are very specific and rare types of thyroid cancer found in rats. And since this is observed in rats when the first GLP-1 drugs have been approved, they came with the FDA, warning that these drugs should not be used in individuals who either have a personal or family history of such tumors such as Medullary thyroid cancerS

Since then, there has been concern whether this is actually happening in humans. So, in the two decades, that this drug class is around, scientists strive to understand: is this something that affects people? And the challenge is that in clinical trials, randomized controlled trials that study these drugs are usually enrolled in several thousand patients. And maybe because this specific type of thyroid cancer is so extremely rare, this risk has not been observed in tests.

So the questions are always: well, is it because tests include patients with very low risk? Because again, since there is this black box warning, tests could never include patients who are consciously at risk, so they may choose for low -risk people. Or do we not see cancers because the tests are generally short? Most of the clinical trials only last up to a few years because they are so expensive to conduct. So, do we not follow patients long enough? Or is there no risk at all?

So research using real -world data are really striving to supplement clinical trial data in order to find rare events. What if we just look at what is happening now when we have millions of people who take these drugs – can we see this signal?

Gizmodo: How do your research from past attempts to seek this signal?

McCoy: We upgrade this truly strong proof that has considered this before. But these studies had some restrictions that we really tried to deal with, and there were some specific things we wanted to do differently.

On the one hand, we only use the largest as possible set of data to do this. So we have insurance information about people with private insurance, for people with Medicare Advantage Insurance, which is now about half people with Medicare and for people with traditional Medicare. So we have people all over the country with different types of insurance, different exposures, different health systems. We were able to include nearly 400,000 patients in general and about 41,000 patients treated with GLP-1, so a very large population of patients using all different types of GLP-1 medicines.

The second is that we looked at the percentages of thyroid cancer, which is diagnosed from the first day of the start of treatment, and onwards, and specifically focused on the first year, then the second, and then. When we looked at the previous literature, many of the differences in the results of the study – some studies find a difference, while others do not find a difference in the risk of cancer – it seems that they come from the fact that some studies do what we have done from the beginning of treatment and on. But other studies have not really considered the first six months or a year, and it is these studies that tend to find a risk increase, while studies that look at the entire period of time, they tend to find an increase. So there was this question: What is happening here?

Gizmodo: Just to clarify, one of the reasons why this moment is important is that it is unlikely that Cancer associated with GLP-1 will appear in just six months from someone who is taking these drugs, right?

McCoy: That’s because thyroid cancer usually takes a long time. Now, of course, there are aggressive cancers that develop rapidly. However, these aggressive cancers are expected to harm patients and make people go to the hospital, need treatment, or even die. And we know this is not happening because we have a lot of literature showing that GLP-1 tends to reduces the risk of deathS

Gizmodo: So, what were the main take on?

McCoy: First, we found that when we looked at the overall study period, there was no increase in the risk of cancer, which was great. However, when we only look at the first year, we saw an increase in risk. So this made us look deeper why could this happen, what drives it?

And we looked at the rate of thyroid ultrasound, so you will find these cancerous diseases of the thyroid gland. We have seen that patients who are started on GLP-1, they have a much higher degree of obtaining thyroid ultrasounds than other patients. And that is important because we know there is a lot of Over diagnosis of thyroid cancerS We find these lesions or nodes in the thyroid gland that when biopsy look like cancer, so we call them cancer. Even so, if we would never find them and have never removed the thyroid gland, patients would probably be well. So these are a very low risk, very slow, if not at all, growing cancers.

Returning to our study, I think what we found is that patients with GLP-1 are more diagnosed with thyroid cancer really very close to the onset of treatment because they receive more ultrasounds.

Gizmodo: This obviously raises the question of why.

McCoy: I think it’s probably three times, although our data cannot specifically tell us this.

One thing that can happen is that patients can feel something on the neck that bothers them like a lump, or maybe they had a recent CT. But if you are worried that there is something in the thyroid gland and if you are taking GLP-1, which has this warning for a black box, people can become more worrying and want to check it to be much more in-depth just because of the recipe.

The second is that some clinicians and patients may even worry about starting GLP-1 if they have no final proof that there is nothing wrong with their thyroid gland. So a slightly prophylactic ultrasound can be done just to be sure, especially if there is a family history of thyroid problems that are very common and are not usually associated with thyroid cancer.

And the third possible explanation is that when people lose weight while taking GLP-1, most weight loss occurs during the first few months of therapy. And as people get smaller, they can now feel nodes during the exam. Again, combined with additional vigilance, doctors may be more sick to biopsy and diagnose cancer.

The key point in this study is that we have shown that GLP-1S leads to more diagnoses of thyroid cancer. But they do not lead to more cases of thyroid cancer because this is the problem. And we know that the people who accept GLP-1 who are their own The risk of dying is lower than patients who are treated with sulfonylureas and DPP-4 (two other classes of diabetes medicines).

Gizmodo: This is obviously not the only study that looks at the risks and benefits of this drug class. In general, where would you say that the calculation is resting right now? For people who are prescribed, do their benefits exceed the risks we know about and which we seek?

McCoy: The way you formulate the question is exactly how patients should think about it. And this is what I tell my patients every time we decide to decide whether a new medicine should start and what this medicine should be. Because it is always a compromise between what are the benefits for a particular patient and what are the potential risks? And this calculation is unique to each person in their position, which is why it is so important that patients speak with their clinicians and understand the balance of the benefits and risks specific to them.

So for GLP-1, we know that there is a great benefit to the reduced events and death for people who have heart disease-the rate of heart attack and stroke is reduced. People who have heart failure have less hospitalizations associated with heart failure. People who have Chronic kidney diseaseThe rate of renal disease is deteriorating and the rate of development of renal failure is slower. People who have extra weight and weaken – problems that are related to weight loss seem to be better. So things like metabolic liver disease, arthritis, sleep apneaThey tend to improve.

So in patients for whom this is important who may have heart disease, kidney disease or complications for obesity, then the benefits of GLP-1 exceed the potential risks, which are usually gastrointestinal side effects. We know that they can cause – though not always – unhees, diarrhea, bloating. In people who lose weight quickly, there is an increased risk of gallstones, as it would be in any type of rapid weight loss. If people lose a lot of weight without exercising, then they lose muscle mass so that they can become more fragile.

So the key is: will you take advantage? And will you be hurt? And can your risk be reduced by lifestyle changes, such as exercising or eating healthier so that you do not have as much nausea, bloating or diarrhea -maybe by eating smaller dishes or less fat dishes or less spicy dishes. So there are always compromises. If I have a patient who has really bad GI side effects, then the benefits may not be worth it because they are so unhappy. But if they tolerate it, I think they are. This is really an individual solution for each patient.