They affect many different pathways associated with tumor development
En el cruce entre la medicina metabólica y la oncología, un estudio de la Universidad de Pensilvania sugiere que los medicamentos GLP-1, recetados para la obesidad y la diabetes tipo 2, podrían reducir en aproximadamente un 30% el riesgo de cáncer de mama en mujeres. Presentado ante la Sociedad Americana de Oncología Clínica, el hallazgo no establece causalidad definitiva, pero abre una nueva dimensión en la búsqueda de herramientas preventivas para una enfermedad que afecta a cientos de miles de mujeres cada año. La ciencia, una vez más, encuentra indicios prometedores donde menos se esperaba.
- Un análisis de más de 111.000 mujeres reveló que quienes tomaban medicamentos GLP-1 desarrollaron cáncer de mama a una tasa hasta 35% menor que quienes no los usaban.
- El hallazgo genera entusiasmo en la comunidad oncológica, pero también cautela: el estudio es observacional y no puede probar que los fármacos sean la causa directa de la reducción.
- Los investigadores apuntan a múltiples mecanismos posibles: pérdida de peso, reducción de la inflamación sistémica y efectos metabólicos que podrían inhibir el desarrollo tumoral.
- Las limitaciones son significativas: no se especificó qué medicamento GLP-1 se usó, por cuánto tiempo, ni el historial genético de las pacientes, lo que podría sesgar los resultados.
- El equipo de Pensilvania ya diseña un ensayo clínico multicéntrico para probar si estos fármacos pueden prevenir el cáncer de mama en mujeres de alto riesgo y reducir las tasas de recurrencia.
Un estudio de la Universidad de Pensilvania presentado en la reunión anual de la Sociedad Americana de Oncología Clínica encontró que las mujeres que tomaban agonistas del receptor GLP-1 —medicamentos para la obesidad y la diabetes tipo 2— mostraron un riesgo de cáncer de mama aproximadamente 30% menor que quienes no los usaban. La investigación analizó a 111.646 mujeres de entre 45 y 80 años con sobrepeso u obesidad que se realizaron mamografías en centros médicos de la Universidad de Pensilvania entre 2022 y 2025. La reducción fue de 35,1% en el grupo general y de 30,5% en un subgrupo controlado por edad, raza, índice de masa corporal y otros factores.
La autora principal, Elizabeth McDonald, señaló que los GLP-1 son fármacos de interés oncológico porque actúan sobre múltiples vías asociadas al desarrollo tumoral. El mecanismo protector probablemente involucra la pérdida de peso —la obesidad es uno de los factores de riesgo más establecidos para el cáncer de mama—, pero también la reducción de la inflamación sistémica y otros efectos metabólicos que podrían inhibir el crecimiento de tumores.
Sin embargo, los investigadores advierten que el estudio es observacional y no puede establecer causalidad directa. No se especificó qué medicamento GLP-1 se utilizó, la duración del tratamiento ni el historial genético de las pacientes. Aun así, McDonald subrayó que los resultados se suman a una creciente evidencia que justifica investigar estos fármacos como herramientas de prevención oncológica.
El equipo ya trabaja en el diseño de un ensayo clínico multicéntrico para evaluar si los GLP-1 pueden reducir la incidencia del cáncer de mama en mujeres de alto riesgo y prevenir su recurrencia. Con más de 320.000 nuevos casos anuales solo en Estados Unidos y más de 22.000 en Argentina, cualquier avance en la prevención de esta enfermedad representa una posibilidad que la ciencia no puede ignorar.
A study from the University of Pennsylvania has found that women taking GLP-1 receptor agonists—drugs prescribed for obesity and type 2 diabetes—show a roughly 30 percent lower risk of developing breast cancer compared to women who do not use them. The finding, presented at the annual meeting of the American Society of Clinical Oncology, suggests a potential new angle on prevention for one of the most common cancers affecting women.
The research examined 111,646 women between 45 and 80 years old who were overweight or obese and received mammograms between January 2022 and June 2025 at University of Pennsylvania medical centers. Of these women, 15,264 had documented prescriptions for GLP-1 medications, while the rest had not received this class of treatment. When researchers compared the two groups, the difference was striking: breast cancer incidence was 35.1 percent lower in those taking GLP-1 drugs, and 30.5 percent lower in a subgroup matched by age, race, body mass index, breast density, and diabetes status. The results were published in JCO Oncology Practice.
Elizabeth McDonald, the study's lead author, noted that GLP-1 medications are "interesting from an oncology research perspective because they affect many different pathways associated with tumor development." She emphasized the team's intention to investigate these drugs further in this context. The protective mechanism likely works through multiple channels. GLP-1 drugs mimic a natural hormone that regulates blood sugar and appetite, and the weight loss they produce could reduce breast cancer risk—obesity being one of the most established risk factors for the disease. Beyond weight reduction, the researchers suggested that GLP-1 medications lower systemic inflammation and produce other metabolic effects that might inhibit tumor growth, a hypothesis supported by earlier research linking inflammation and excess weight to cancer development.
Yet the enthusiasm comes tempered with caution. The study is observational, meaning it cannot establish a direct causal relationship between GLP-1 use and reduced breast cancer incidence. McDonald acknowledged several limitations: the analysis did not specify which exact GLP-1 medication was used, how long patients took the drugs, genetic history, or cancer stage at diagnosis. Some patients may have obtained the medications through alternative channels like telemedicine or compounding pharmacies, potentially skewing results. "Although the study is observational and does not definitively confirm the association between GLP-1 medications and reduced breast cancer incidence, it does add to the growing body of evidence suggesting these drugs merit investigation as potential cancer prevention tools," McDonald said.
The Pennsylvania team is already designing a multicenter clinical trial to test whether GLP-1 drugs can reduce breast cancer incidence in high-risk women and prevent recurrence. "We want to find better options for preventing breast cancer," McDonald stated. Bernard Fuemmeler, associate director of the Virginia Commonwealth University Massey Comprehensive Cancer Center, called the approach sound: "Reducing cancer risk in people with greater risk factors is the path forward in cancer prevention." Breast cancer accounts for roughly one-third of all cancer diagnoses in women, with more than 320,000 new cases annually in the United States alone and over 22,000 new cases each year in Argentina. While survival rates have improved in recent decades, the disease remains one of the leading causes of cancer death among women, making any potential preventive tool worth serious investigation.
Notable Quotes
We want to find better options for preventing breast cancer— Elizabeth McDonald, lead author
Reducing cancer risk in people with greater risk factors is the path forward in cancer prevention— Bernard Fuemmeler, Virginia Commonwealth University Massey Comprehensive Cancer Center
The Hearth Conversation Another angle on the story
So this study looked at over 100,000 women. What made them choose that particular group?
They focused on women between 45 and 80 who were overweight or obese—the population most at risk for both the conditions these drugs treat and for breast cancer itself. That made the comparison meaningful.
And the 30 percent reduction—is that the same across all the women they studied, or did it vary?
It varied slightly. The raw comparison showed 35 percent lower incidence, but when they matched women more carefully by age, race, body mass index, and other factors, it came down to 30.5 percent. That second number is probably more reliable because it controls for confounding variables.
The researchers mention inflammation. How does that connect to cancer?
GLP-1 drugs reduce systemic inflammation throughout the body. Chronic inflammation is known to fuel tumor growth and progression. So the drugs might be working on cancer risk through that pathway, independent of weight loss alone.
But they can't prove that's actually what's happening, right?
Exactly. This is observational research—they watched what happened to women already taking these drugs. They can't say the drugs caused the reduction. There could be other factors they didn't measure. That's why they're planning a randomized trial.
What would a randomized trial actually tell them that this study couldn't?
It would randomly assign women to either take GLP-1 drugs or a placebo, then follow them over time. That would let them isolate the drug's effect from everything else—lifestyle changes, access to better healthcare, genetic factors. It's the gold standard for proving causation.
How soon might women actually benefit from this if the trial works out?
That depends on the trial's timeline and results. These studies typically take years. But the fact that researchers are moving this direction suggests they see enough promise to invest the time and money.