Fertility preservation for breast cancer patients using tamoxifen or letrozole

Fertility Preservation Using Tamoxifen and Letrozole in Estrogen Sensitive Tumors Trial

Phase 3 Interventional University of California, San Francisco · NCT03011684

This study is testing whether tamoxifen or letrozole works better with fertility drugs to help women with breast cancer save their eggs before treatment.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment309 (estimated)
Ages18 Years to 50 Years
SexFemale
SponsorUniversity of California, San Francisco Academic / other
Drugs / interventionschemotherapy
Locations1 site (San Francisco, California)
Trial IDNCT03011684 on ClinicalTrials.gov

What this trial studies

This trial aims to compare the effectiveness of tamoxifen and letrozole in conjunction with gonadotropins for ovarian stimulation in women with estrogen-receptor-positive breast cancer who wish to preserve their fertility before undergoing cancer treatment. The primary objective is to determine which regimen results in a higher yield of mature oocytes during the stimulation process. Secondary aims include evaluating hormone levels and embryo quality during the ovarian stimulation cycle. The study is designed to improve the quality of life for reproductive-age cancer survivors by enhancing fertility preservation options.

Who should consider this trial

Good fit: Ideal candidates are women aged 18 and older with a new diagnosis of estrogen-receptor-positive breast cancer who have not yet started chemotherapy and wish to undergo ovarian stimulation.

Not a fit: Patients who have already begun chemotherapy, have a history of recurrent breast cancer, or have stage IV breast cancer are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, this study could significantly improve fertility preservation outcomes for women diagnosed with breast cancer.

How similar studies have performed: Other studies have shown promising results with similar approaches to fertility preservation in breast cancer patients, indicating that this method is not entirely novel but still holds significant potential.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* New breast cancer diagnosis
* Has not yet begun chemotherapy
* Desires to undergo ovarian stimulation and oocyte retrieval prior to cancer treatment
* Age 18 years old or greater

Exclusion Criteria:

* Chemotherapy has already commenced or been completed
* History of recurrent breast cancer (with a prior history of chemotherapy)
* Stage IV breast cancer diagnosis (metastases remote from the breast)
* Patient's oncologist advises against the trial - in which case they can choose to receive stimulation with letrozole+gonadotropin
* Does not plan to undergo ovarian stimulation and oocyte retrieval prior to diagnosis
* Any significant concurrent disease, illness, or psychiatric disorder that would compromise patient safety or compliance, interfere with consent, study participation, follow-up, or interpretation of study results
* Age less than 18 years old

Where this trial is running

San Francisco, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions InfertilityFertility PreservationBreast Cancer
Last reviewed 2026-06-10 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.