Examining the effects of tamoxifen on immune response in breast cancer patients

Neutrophil Functions in Breast Cancer

Observational M.D. Anderson Cancer Center · NCT05056857

This study is testing how tamoxifen affects the immune response in breast cancer patients to see if it changes the way their body fights cancer and handles treatment side effects.

Quick facts

Study typeObservational
Enrollment290 (estimated)
Ages18 Years and up
SexFemale
SponsorM.D. Anderson Cancer Center Academic / other
Locations1 site (Houston, Texas)
Trial IDNCT05056857 on ClinicalTrials.gov

What this trial studies

This observational study investigates the long-term effects of tamoxifen treatment on the formation of neutrophil extracellular traps (NETs) in breast cancer patients. It aims to understand how tamoxifen influences NET production and its potential implications for cancer progression and treatment side effects. Blood samples will be collected from participants, and their medical records will be reviewed to correlate NET levels with clinical outcomes, including drug resistance and metastasis. The study also includes a control group of newly diagnosed patients receiving tamoxifen for a shorter duration.

Who should consider this trial

Good fit: Ideal candidates are female breast cancer patients aged 18-50 who have been on tamoxifen for at least 6 months or newly diagnosed patients on tamoxifen for 0-6 months.

Not a fit: Patients who are pregnant or have not been diagnosed with ER+ breast cancer will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into the immune response in breast cancer patients and help optimize tamoxifen treatment.

How similar studies have performed: While the specific focus on NETs in the context of tamoxifen is novel, related studies have explored immune responses in cancer treatment with varying degrees of success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Female
* Age criteria for pre-menopausal group: Equal to or greater than 18 years of age and less than or equal to 45 years of age. Patients of age 46-50 will be included if they have not had menstrual cessation for 12 consecutive months.
* Age criteria for menopausal group: At least 51 years of age (median age of menopause). Menopause is defined as cessation of menstrual cycle for 12 consecutive months.
* Diagnosed with ER+ breast cancer
* Being treated with tamoxifen (TAM) for at least 6 months
* CONTROL SUBJECTS: Newly diagnosed ER+ breast cancer patients of the same age group as above on TAM for 0-6 months. This criterion is based on our preliminary results showing that patients taking TAM for 6-7 months exhibit near baseline level of NETs

Exclusion Criteria:

* Pregnant -The immune modulations geared toward maintenance of pregnancy are known to cause wide-spread alterations in innate and adaptive immune cell functions. In this scenario, divorcing the pregnancy-related changes in myeloid cell function from those relevant to sepsis and cancer will be complicated.
* History of severe congenital neutropenia due to genetic disorders, such as Kostmann Disorder (HAX1 gene mutation), ELA2 gene mutation, Wiskott-Aldrich syndrome (WAS), Growth Factor Independent 1 Protein (GFI1) gene mutation, Colony Stimulating Factor 3 Receptor (CSF3R) gene mutation, Schwachman-Diamond Syndrome, Barth Syndrome, WHIM Syndrome, and Chadiak-Higashi Syndrome (this list notably does not include Myelodysplastic Syndrome, or Acute/Chronic Myeloid Leukemia)
* History of autoimmune disorders, which can affect the body's inflammatory response, such as rheumatoid arthritis, lupus, Crohn's disease, multiple sclerosis, and psoriasis.
* History of chronic viral infections (human immunodeficiency virus \[HIV\], hepatitis), which can lead to reduced or variable immune cell function.
* A recent positive coronavirus disease (COVID) test

Where this trial is running

Houston, Texas

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 Carcinoma
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.