Registry of women with breast cancer during or after pregnancy

An Ambispective Observational Registry Study of Pregnancy and Breast Cancer

Observational Spanish Breast Cancer Research Group · NCT04603820

This study is trying to learn more about breast cancer in women who are pregnant or have been pregnant, by collecting information and samples from them to see how different factors might affect their cancer.

Quick facts

Study typeObservational
Enrollment1000 (estimated)
Ages18 Years and up
SexFemale
SponsorSpanish Breast Cancer Research Group Academic / other
Locations28 sites (Oviedo, Asturias and 27 other locations)
Trial IDNCT04603820 on ClinicalTrials.gov

What this trial studies

This is an ambispective observational registry study that aims to collect data on women with breast cancer in three specific scenarios: those diagnosed during pregnancy, those who become pregnant after a breast cancer diagnosis, and those who have undergone fertility preservation techniques prior to treatment. The study will gather clinical characteristics and high-quality molecular data from biological samples to evaluate associations between breast cancer subtypes and various risk factors. It will enroll patients over a minimum recruitment period of three years, allowing for both retrospective and prospective data collection. The study is designed to enhance understanding of breast cancer in the context of pregnancy and fertility.

Who should consider this trial

Good fit: Ideal candidates include women aged 18 and older with breast cancer diagnosed during pregnancy, those who become pregnant after treatment, or those who have utilized fertility preservation methods.

Not a fit: Patients with breast cancer who do not fall into the specified categories or who are under 18 years old may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide valuable insights into the management of breast cancer in pregnant women and those wishing to conceive post-diagnosis.

How similar studies have performed: While there have been studies on breast cancer and pregnancy, this registry approach is relatively novel and aims to fill gaps in existing research.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. The patient should have signed and dated the informed consent form (ICF). The enrollment of patients who have died is allowed.
2. Women aged ≥ 18 years.
3. Patients in one of the following situations:

   * Patients with breast cancer diagnosis during pregnancy, breastfeeding or within the year after delivery.
   * Patients with breast cancer who become pregnant after treatment.
   * Patients with breast cancer who were subjected to any fertility preservation method prior to the start of breast cancer treatment.
4. The patients referred to in the previous section and the patients who meet these characteristics prospectively could be enrolled retrospectively upon registry opening.
5. All cases diagnosed at the same site may be included. In order to prevent duplications, in case the patient followed her treatment and follow-up at another site, she will be enrolled as per the site where the diagnosis was made, requesting information of the treatment and progression, when possible.
6. Availability of clinical, epidemiological and progress data.

Exclusion Criteria:

Patients who do not wish to participate in the study for any reason could not be included in the study.

Where this trial is running

Oviedo, Asturias and 27 other locations

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 Breast Cancer and PregnancyPregnancyGestational breast cancerFertility preservation techniqueBreast Cancer
Last reviewed 2026-06-13 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.