Next-generation anti-diabetes drug tirzepatide, marketed as Mounjaro for diabetes and Zepbound for obesity, reduced obesity-associated breast cancer growth in recent mouse experiments.
Study author Amanda Kucinskas, is a Ph.D. candidate in the labs of Drs Erin Giles and Kanakadurga Singer at the University of Michigan in Ann Arbor, Mich. Her study will be presented to the Annual Meeting of the Endocrine Society, Endo 2025, coming up soon in San Francisco.
What she did
This mouse study included 16 especially-bred mice. The 9-week-old C57BL/6 mice were fed a 40 percent high-fat diet and housed in a warm environment to induce obesity. At 32 weeks of age, the mice with obesity were randomly assigned injections of tirzepatide or a placebo every other day for 16 weeks. Tumor volumes were measured twice weekly.
What they found
Scientists were not particularly caught off guard when the drug produced marked weight loss Tir-zepatide, marketed as Mounjaro for diabetes and Zepbound for obesity, was associated with 20 percent overall body weight loss in mice to whom it was given. It’s a newly marketed member of the GLP-1 receptor meds daily being hailed as both diabetes and obesity fighters.
But when experimenters saw that reduction in tumour was was also significantly correlated with body weight, total adipose mass and the amount of fat stored in the liver, they started to get excited.
The takeaway
“Obesity is a significant risk factor for breast cancer, and while it is very preliminary data, our studies in mice suggest that these new anti-obesity drugs may be a way to reduce obesity-associated breast cancer risk or improve outcomes,” said study author Amanda Kucinskas.
She also suggests further studies specifically on the new suspected the tumor-specific effects of tirzepatide…
My take
Any new research that may shed welcome light on breast cancer will definitely be welcomed by thou-sands of researchers, and millions of women ’round the world with known or suspected elevated cancer risk.
Follow-up studies are already under way attempting to separate weight loss effects from the tumor-specific effects of tirzepatide.
The sooner, the better, I say. And keep us up to date on your efforts, Amanda!
~ Maggie J.