Emerging Insights on Weight Loss Drugs and Cancer
A growing body of research indicates that widely used weight loss medications like Ozempic and Wegovy may also play a role in treating or preventing certain cancers. This unexpected benefit is being linked to GLP-1s, which are now utilized by about one in eight adults in the U.S.
William Brangham has more details on this topic.
The current findings are largely based on observational studies, which are less rigorous than clinical trials, and researchers acknowledge that many questions remain unanswered. However, a recent conference among leading cancer specialists highlighted a consistent observation: GLP-1s seem to aid in cancer prevention beyond just the weight loss effects.
To unpack the implications and limitations of these studies, we consulted Dr. Neil Iyengar, who leads breast oncology and cancer survivorship at the Winship Cancer Institute at Emory University.
Dr. Iyengar, thanks for joining us. There’s increasing observational evidence suggesting that GLP-1s could be beneficial concerning cancer. Overall, what have these studies shown?
Dr. Neil Iyengar, Emory University School of Medicine: Thank you for having me. This is indeed exciting and important data. We’ve known for quite a while that obesity is linked to an elevated risk for at least 13 different cancers, and possibly even 20. Hence, addressing obesity has been a crucial area of research.
Up until now, effective weight loss methods were limited, but GLP-1 receptor agonists have changed that landscape. The studies you mentioned are proposing a fascinating theory. I say “theory” because, as pointed out, they are observational. However, the data support the notion that weight loss induced by GLP-1 receptor agonists may not only help prevent obesity-related cancers but could also curb their recurrence post-diagnosis.
William Brangham: That’s quite compelling. I want to share some specifics from these studies. An analysis from the University of Pennsylvania revealed that women aged 45 to 80 who used these drugs had about a 30% lower risk of developing breast cancer compared to those who didn’t. Another survey looked at patients with seven types of early-stage cancers and found that GLP-1s significantly decreased the risk of metastasis in four types: lung, breast, colon, and liver. Do you think the main factor here is simply the weight loss?
Dr. Neil Iyengar: I believe so. Previous studies employing methods like diet or exercise—resulting in lesser weight loss—still indicated a reduction in the risk of obesity-related cancers, albeit not as pronounced. What we understand from studies on more extensive weight loss methods, such as bariatric surgery, is that the greater the weight loss among individuals with obesity, the lower the likelihood of developing or recurring cancer.
Therefore, it makes sense that the significant weight loss induced by GLP-1 receptor agonists, comparable to that from bariatric surgeries, is associated with lowered cancer risk. While some evidence suggests that GLP-1s exert anti-inflammatory effects and have potential immune-related benefits, the primary driver remains their ability to facilitate substantial weight loss, unlike other diabetes medications.
William Brangham: If these studies continue to show a genuine effect, how transformative would that be for oncological practices?
Dr. Neil Iyengar: We could be on the brink of a major change regarding the health burdens posed by obesity and its related cancers. It’s noteworthy that obesity accounts for a significant portion of cancer-related deaths—one in seven for men and one in six for women. Reducing obesity, which is manageable with GLP-1s, could drastically alter the landscape of obesity-related cancers. However, we must proceed cautiously, as there are varied data on the effects concerning different cancers and how these drugs interact with cancer therapies. Continued, meticulous research on these drugs is vital for safe and effective usage to mitigate cancer risk.
William Brangham: Given the current knowledge—you’re an expert on breast cancer—would you recommend GLP-1s to your patients as a preventative measure or for those currently undergoing treatment?
Dr. Neil Iyengar: That’s a complex issue right now. We really need to depend on the observational data available. My concern is that we still lack insights on potential interactions between GLP-1s and cancer treatments. For cancer survivors who are cancer-free but facing obesity, using a GLP-1 could help manage weight and thereby lower the recurrence risk related to obesity.
However, for those actively undergoing treatments like chemotherapy or immunotherapy, we currently don’t have enough information about how these drugs might interact, which makes me hesitant to recommend them in that context. If a patient is in that situation, it’s definitely worth discussing with their oncologist, but I’d be cautious about suggesting use until further data becomes available.
William Brangham: Thank you, Dr. Neil Iyengar of Emory University, for sharing your insights.
Dr. Neil Iyengar: Thank you for having me.
