GLP-1s in Breast Cancer: Overall Survival, Recurrence Risk, and Safety

As more patients with breast cancer inquire about using GLP-1 receptor agonists to manage treatment-related weight gain, clinicians must look closely at long-term safety and survival data. Sherry Shen, MD, highlighted promising data from recent database studies indicating a strong signal toward improved overall survival. She said this benefit makes clinical sense, as GLP-1s actively improve glycemic control, optimize lipid profiles, and boost cardiovascular health, directly targeting the leading cause of post-diagnosis mortality. Finally, Shen addressed the current unknowns surrounding breast cancer recurrence risk, offering reassurance that no negative recurrence signals have been observed to date for patients maximizing their lifestyle adjustments.

Shen is an assistant attending physician at Memorial Sloan Kettering Cancer Center.

To read more about GLP-1s and their use in cancer care, visit: cancernetwork.com/view/obesity-and-cancer-risk-the-evolving-role-of-glp-1s-in-oncology

Transcript:

I’ll put this in the context of several other studies that have since come out. One of the subsequent studies to look at GLP-1s in [patients with] breast cancer came out of MD Anderson, [and] was led by Jasmine Sukumar, MD, and they looked at a bigger group of patients. They had very similar findings, where they saw that about 80% of their patients were taking [GLP-1s] for diabetes indications, and the weight loss ranged in the 2% to 3% range, [which] is even more modest than what we would expect. There have been subsequently a couple database studies that have come out, also with larger numbers of patients with breast cancer on GLP-1s, and it does seem like there is a signal towards improved overall survival.

That makes sense, right? These GLP-1s have so many benefits; they improve glycemic control [of] hemoglobin A1_c and glucose. They improve lipid profile, so they may lower cholesterol. They improve cardiac health—the number one cause of death after breast cancer diagnosis. It makes sense that these drugs are improving overall survival long term for our [patients with] breast cancer. [It’s] unclear if it had an association with decreasing breast cancer recurrence risk. That’s something that’s still a big question for us, but it does seem like there’s that overall survival benefit. I have a lot of patients ask me about GLP-1s, particularly patients on endocrine therapy, maybe several years out from their diagnosis. They’re saying, “I’m struggling with losing weight, I’m [dieting], I’m [exercising]. I don’t know what else to do. I’ve been thinking about a GLP-1; is that something that is safe to do?” I tell people what we know, which are currently from retrospective data, is that people do lose weight. You may lose less weight than someone who doesn’t have a breast cancer diagnosis, who isn’t taking active endocrine therapy, but people do lose weight, and that amount of weight may be meaningful. There is a significant benefit, it looks like, on many other things—like cholesterol, glycemic control, and cardiac health—that could be beneficial long term. We just don’t know about the breast cancer recurrence risk, and yet there are no negative signals. There’s no signal so far that said, “Oh, those who are on GLP-1s may have a higher recurrence risk.” That has not been the case. I feel very reassured by those data, and I tell patients, “If you’ve maximized the lifestyle changes and you feel like this would be right for you, I’m open to that from a breast cancer perspective.”