Researchers at the University of Basel have discovered a promising new effect of the drug dexamethasone: The synthetic stress hormone, which has so far been used primarily to alleviate chemotherapy side effects such as nausea and inflammation, could reduce the formation of therapy-resistant metastases in certain types of breast cancer. The results were published in the journal “EMBO Molecular Medicine”.

The study focused on the “estrogen receptor-positive” (ER+) subtype, which is treated with anti-hormone therapies that block the overactive estrogen receptor that drives tumor growth. However, some patients develop metastases that no longer respond to this therapy. This is where the new finding comes in: Dexamethasone activates the glucocorticoid receptor, which inhibits the production of the estrogen receptor and thus switches off the main driver of tumor growth.

In experiments with mice infected with therapy-resistant ER+ tumors, dexamethasone significantly reduced liver metastases and extended the survival of the animals. The scientists observed similar effects in laboratory tests with organoids – artificially cultured tumor tissue from breast cancer patients – where the amount of estrogen receptor decreased after dexamethasone was added.

The head of the project, Dr. Charly Jehanno, sees the potential to integrate dexamethasone directly into the fight against cancer beyond its previous role as an adjunctive drug. However, he emphasizes that the results must first be confirmed in breast cancer patients. Prof. Dr. Mohamed Bentires-Alj, head of the research team, also warns that dexamethasone is not universally applicable: In triple-negative breast cancer, as already shown in the “Nature” journal in 2019, it could even promote metastasis. The effect therefore depends strongly on the cancer subtype.

If the positive effects are confirmed, the established drug could be a cost-effective addition to the treatment of treatment-resistant ER+ breast cancer cases – a step that raises new hopes for affected patients.

Original Paper:

Madhuri Manivannan et al.
Activated Glucocorticoid Receptor is an Estrogen Receptor Silencer in ER+ metastatic breast cancer
EMBO Molecular Medicine (2025), doi: 10.1038/s44321-025-00342-z

Editor: X-Press Journalistenbüro GbR

Gender Notice. The personal designations used in this text always refer equally to female, male and diverse persons. Double/triple naming and gendered designations are used for better readability. ected.