Tamoxifen

History

2025: Increased risk of uterine tumour

At the end of August 2025, an international research group reported the identification of a previously unknown mechanism by which the drug Tamoxifen for the treatment of breast cancer can increase the risk of secondary tumors in the uterus.

Since its introduction in the 1970s, Tamoxifen has significantly improved survival rates for patients with a particular type of breast cancer. However, this drug is associated with an increased risk of uterine tumor. Previously, the exact molecular cause of this side effect remained unclear.

𝓲

Фото: Freepik

The study was attended by scientists from the Berlin Institute of Health in Charite (BIH), the Massachusetts Institute of Technology and Harvard, the Dana-Farber Cancer Research Institute, etc. Experts have found that Tamoxifen directly activates a key cellular signaling pathway (known as PI3K), which is a central factor in the development of sporadic uterine cancer.

Our results show for the first time that activation of the pro-tumor signaling pathway by a drug is possible, and provide an explanation at the molecular level of how a highly successful anti-cancer drug can paradoxically promote tumor development in another tissue, says Professor Kirsten Kübler, one of the authors of the work.

Although the overall risk of developing uterine cancer with Tamoxifen therapy remains very low, and the benefit of the drug significantly outweighs the possible negative consequences, the results of the study open up new opportunities to further improve the safety of treatment. In addition to biologically explaining this long-standing medical mystery, the discovery lays the groundwork for the development of personalized tumor prevention and therapy strategies.^[1]

Notes