This could prove to be a major medical breakthrough

Major new research has linked taking one of the most popular weight loss drugs with shrinking breast cancer, and it could lead to it become a major treatment option in the near future for affected patients.

Cancer across its many forms is notoriously hard for doctors to fight, as while the primary chemotherapy route does have moderate levels of success, it continues to prove challenging to properly eradicate and cure.

Certain recent studies have discovered miraculous methods in 'eureka moments' that link the consumption of something as simple as aspirin to reduced cancer risk, and another breakthrough appears to have been reached in conjunction with a popular weight loss drug.

Tirzepatide, otherwise known as Mounjaro, has been linked to breast cancer tumor reduction in a breakthrough study (Peter Dazeley via Getty Images)

What weight loss drug could be used as cancer treatment?

As reported by ScienceDaily, popular weight loss GLP-1 inhibitor tirzepatide, more popularly known as 'Mounjaro', has been shown to reduce the size of breast cancer related tumors in conjunction with weight loss in a recent study involving mice.

The study, presented at the recent ENDO 2025 conference, shows that obesity-associated breast cancer growth might be able to be combatted with the use of tirzepatide, adding another benefit to the originally diabetes-focused injection.

"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," outlines lead author Amanda Kucinskas, a PhD candidate at the University of Michigan.

How does the treatment reduce cancer?

The study itself involved 16 different mice that were fed a 40% high-fat diet and kept in a warm environment in order to encourage obesity to form. After 32 weeks, mice with obesity were injected either tirzepatide or a placebo drug every other day for the next 16 weeks, with tumor volumes measured twice every day for that period.

Mice injected with tirzepatide were shown to have reduced tumor sizes in correlation with weight loss (Peter Dazeley via Getty Images)

Body weight and body fat were reduced by around 20% in the mice that were injected with tirzepatide, which equates with the average losses of human women when taking the drug.

Tumor volume reduced in tandem with the weight loss, appearing to showing a clear correlation between the rapid weight loss caused by a drug like tirzepatide and a positive impact on existing cancer-related tumors.

It remains, as Kucinskas outlines, preliminary data right now and there will have to be significant further tests and experiments to truly evaluate the merits and long term effects of taking this drug in conjunction with obesity-linked breast cancer, but it remains still a remarkable breakthrough that could completely change how treatment is offered in the future.