Could a daily pill lower breast cancer risk by reducing breast density?

NCT ID NCT05068388

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This study tested an oral drug called (Z)-endoxifen in 240 premenopausal women with high breast density, a known risk factor for breast cancer. Over six months, researchers measured changes in breast density using mammogram software. The goal was to see if the drug could safely reduce density compared to a placebo.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

(Z)-endoxifen

What this could lead to

If successful, this could lead to a non-surgical option to reduce breast density and potentially lower breast cancer risk in premenopausal women.

What could go wrong

This is a phase 2 study with 240 participants, so results are still early. The drug may not significantly reduce density or could cause side effects like hot flashes or blood clots.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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Conditions

The condition(s) this trial relates to.

breast cancer prevention target

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Karma Study Centre

    Stockholm, Sweden