Egg-Freezing showdown: tamoxifen vs letrozole for breast cancer patients

NCT ID NCT03011684

Recruiting now Disease control Sponsor: University of California, San Francisco Source: ClinicalTrials.gov ↗

First seen Jun 24, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This phase 3 trial tests whether tamoxifen or letrozole works better for preserving fertility in women with estrogen-sensitive breast cancer before starting chemotherapy. About 309 participants will take one of the two drugs during ovarian stimulation to freeze their eggs. The main goal is to see which drug leads to more mature eggs retrieved.

What this could mean

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

Active substance: Tamoxifen and letrozole (oral drugs)
What this could lead to: If it works, this could help doctors choose the best drug to maximize egg yield for fertility preservation in breast cancer patients.
What could go wrong: This trial is still recruiting and results are not yet available. The drugs may not differ significantly in egg yield, and individual responses vary.

This is an AI summary of the original study and may miss details. Read our disclaimer.

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Conditions

The condition(s) this trial relates to.

breast neoplasm estrogen-receptor positive breast cancer infertility disorder

As listed by the trial registrant

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

INFERTILITY

Contacts and locations

Locations

University of California at San Francisco
RECRUITING

San Francisco, California, 94143, United States

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