Tamoxifen

Gut microbes · 2026

Researchers found that tamoxifen, a common breast cancer treatment, can cause liver damage in nearly half of patients. They observed that this liver injury is linked to changes in gut bacteria and a decrease in a specific bile acid, which disrupts important liver signaling pathways.

• Tamoxifen can cause significant liver damage in about 50% of patients.
• The liver injury is associated with changes in gut microbiota.
• A specific bile acid depletion disrupts liver signaling pathways.

Osteoarthritis and cartilage · 2025

Researchers observed that tamoxifen (TAM), commonly used for breast cancer treatment, negatively impacts bone and cartilage development in mice. Specifically, TAM led to significant changes in cartilage metabolism and impaired fracture healing, while not affecting the skeletal structure of newborn mice. These findings suggest that TAM's effects on bone health need further investigation, especially in experimental settings.

• TAM caused a complete loss of the growth plate in aged mice.
• TAM decreased cartilage area in trauma-induced osteoarthritis.
• TAM impaired the fracture healing process by altering gene expression in bone and cartilage cells.

Cancer letters · 2024

Researchers found that tamoxifen resistance in breast cancer cells is linked to abnormal mitochondrial behavior, specifically increased fusion and decreased fission. By inhibiting a protein called MFN1, they were able to restore the cancer cells' ability to undergo programmed cell death, making them more responsive to tamoxifen treatment. This suggests that targeting mitochondrial dynamics could be a potential strategy to overcome tamoxifen resistance.

• Dysregulated mitochondrial dynamics contribute to tamoxifen resistance.
• Inhibiting MFN1 restores apoptosis in resistant cells.
• Targeting MFN1-mediated mitochondrial fusion may improve tamoxifen treatment outcomes.

Redox biology · 2023

Researchers found that a protein called RelB helps breast cancer cells resist tamoxifen, a common treatment, by preventing a type of cell death known as ferroptosis. They observed that increasing levels of RelB and another protein, GPX4, in sensitive cells made them more resistant to tamoxifen, while reducing these proteins in resistant cells made them more sensitive to the treatment.

• RelB contributes to tamoxifen resistance in breast cancer by inhibiting ferroptosis.
• Higher levels of RelB and GPX4 in sensitive cells increase resistance to tamoxifen.
• Decreasing RelB and GPX4 in resistant cells enhances their sensitivity to tamoxifen.

Survey of ophthalmology · 2023

Researchers observed that tamoxifen, a drug used to treat breast cancer, can affect the eyes, specifically the retina and choroid, with reported toxicity rates between 0.9% and 12%. They found that symptoms can develop anywhere from 3 weeks to 13 years after starting treatment, and while there is no standard screening method, certain imaging techniques may help detect early eye damage.

• Tamoxifen can cause retinal and choroidal toxicity.
• Toxicity rates range from 0.9% to 12%.
• Symptoms can appear 3 weeks to 13 years after starting tamoxifen.

Cancer treatment reviews · 2002

Researchers observed that tamoxifen has been an effective treatment for breast cancer for over 30 years, used in both early and advanced stages. Its ability to work well for both pre- and postmenopausal women, along with its good tolerability, keeps it as a preferred option for patients with oestrogen-receptor positive breast cancer.

• Tamoxifen is effective for both early and advanced breast cancer.
• It works well for both pre- and postmenopausal women.
• Ongoing studies are exploring the best duration of treatment and comparisons with newer therapies.

Journal of biochemical and molecular toxicology · 2002

Researchers found that 4-hydroxytamoxifen, a metabolite of the breast cancer drug tamoxifen, can be processed by human liver and intestinal enzymes, which helps detoxify the drug. In contrast, rats do not show this detoxification ability, indicating that tamoxifen may be more toxic to them than to humans. This suggests different metabolic pathways for tamoxifen in humans and rats.

• 4-hydroxytamoxifen can be sulfated by human liver and intestinal enzymes.
• The sulfation process helps detoxify tamoxifen in humans.
• Rats lack the ability to detoxify 4-hydroxytamoxifen, making tamoxifen more toxic to them.

American journal of clinical oncology · 1999

Researchers observed that thrombocytopenia, a condition with low platelet counts, can occur as a rare side effect of tamoxifen, a medication used for breast cancer treatment. In a reported case, a patient developed this condition six months after starting tamoxifen, but it resolved when the medication was stopped and returned when it was restarted. The patient's platelet counts remained normal after switching to a different medication, anastrozole.

• Thrombocytopenia is a rare side effect of tamoxifen.
• The condition resolved after stopping tamoxifen and returned upon restarting.
• Switching to anastrozole resulted in normal platelet counts.

Drug design and delivery · 1988

Researchers described the history behind the discovery of Nolvadex, a medication used to treat breast cancer. This anti-estrogen drug, known scientifically as tamoxifen, has become a vital part of breast cancer treatment due to its effectiveness in combating the disease.

• Nolvadex is widely used in breast cancer treatment.
• The drug is classified as an anti-estrogen.
• The research highlights the contributions of the chemist involved in its discovery.