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Estradiol Levels According to Body Mass Index in Premenopausal Patients With Breast Cancer (SIMPEC-E2)

16 september 2026 bijgewerkt door: D'Or Institute for Research and Education

Evaluation of Serum Estradiol Levels According to Body Mass Index Categories in Premenopausal Patients With Hormone Receptor-Positive Breast Cancer Receiving Aromatase Inhibitors and Pharmacologic Ovarian Suppression

his prospective observational study will evaluate whether body mass index (BMI) is associated with serum estradiol levels in premenopausal women with hormone receptor-positive breast cancer. Participants will already be receiving standard adjuvant treatment with an aromatase inhibitor and pharmacologic ovarian suppression as part of their routine clinical care. The study will not assign or modify cancer treatment.

Approximately 172 participants will be enrolled at multiple study sites in Brazil. They will be classified into two main groups: normal BMI and overweight or obesity. Clinical information, medication use, physical activity, weight, height, and serum estradiol levels will be recorded. Estradiol will be measured using an ultrasensitive laboratory method, with the main assessment occurring after approximately three months of treatment.

The primary objective is to compare the proportion of participants with serum estradiol levels above 2.72 pg/mL between the two BMI groups. The study will also examine the relationship between BMI and absolute estradiol levels and explore whether clinical characteristics, previous chemotherapy, physical activity, or use of glucagon-like peptide-1 receptor agonists are associated with inadequate estrogen suppression.

Studie Overzicht

Toestand

Nog niet aan het werven

Conditie

Gedetailleerde beschrijving

This is a multicenter, prospective, observational cohort study designed to evaluate the association between body mass index (BMI) and serum estradiol levels in premenopausal women with hormone receptor-positive invasive breast cancer receiving adjuvant endocrine therapy with an aromatase inhibitor combined with pharmacologic ovarian suppression using a gonadotropin-releasing hormone analog.

All endocrine treatments will be prescribed as part of routine clinical care. Participation in the study will not determine the selection, dose, schedule, continuation, or modification of anticancer treatment. No experimental intervention, treatment allocation, or randomization is planned.

Approximately 172 participants will be enrolled. For the primary analysis, participants will be classified according to World Health Organization BMI categories and grouped as having normal BMI or overweight/obesity. At enrollment, demographic, anthropometric, clinical, and oncologic information will be collected, including tumor characteristics, previous cancer treatment, type and timing of aromatase inhibitor and ovarian suppression therapy, concomitant medications, physical activity, and use of glucagon-like peptide-1 receptor agonists.

Weight and height will be measured to calculate BMI. Serum estradiol will be assessed using an ultrasensitive laboratory method. A baseline estradiol measurement may be obtained when applicable, depending on the timing of enrollment. The main estradiol assessment will be performed after approximately three months of combined aromatase inhibitor therapy and pharmacologic ovarian suppression, within a protocol-defined visit window of plus or minus 14 days. If a result suggests inadequate estrogen suppression, an additional measurement may be requested within 14 days using a different laboratory method, according to institutional practice and local availability.

The primary outcome is the proportion of participants with inadequate estrogen suppression, defined as a serum estradiol concentration greater than 2.72 pg/mL after approximately three months of treatment. This proportion will be compared between participants with normal BMI and those with overweight/obesity.

Secondary and exploratory analyses will evaluate absolute estradiol concentrations across BMI categories, the correlation between BMI and serum estradiol, a potential BMI cutoff associated with inadequate estrogen suppression, and clinical characteristics associated with inadequate suppression. Exploratory subgroup analyses will consider previous chemotherapy, physical activity, and use of glucagon-like peptide-1 receptor agonists.

The primary comparison will use a chi-square test or Fisher's exact test, as appropriate. Binary logistic regression will assess the association between BMI and inadequate estrogen suppression, with BMI evaluated as both a categorical and continuous variable and adjustment for clinically relevant potential confounders. Continuous outcomes will be analyzed using parametric or nonparametric methods according to their distributions. The relationship between BMI and estradiol concentration will also be assessed using Spearman correlation, and receiver operating characteristic curve analysis will be used to explore a potential BMI cutoff associated with inadequate estrogen suppression.

Studietype

Observationeel

Inschrijving (Geschat)

172

Contacten en locaties

In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.

Studiecontact

Deelname Criteria

Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.

Geschiktheidscriteria

Leeftijden die in aanmerking komen voor studie

18 jaar en ouder (Volwassen, Oudere volwassene)

Accepteert gezonde vrijwilligers

Ja

Geslachten die in aanmerking komen voor studie

Vrouw

Bemonsteringsmethode

Niet-waarschijnlijkheidssteekproef

Studie Bevolking

Premenopausal adult women with histologically confirmed hormone receptor-positive invasive breast cancer receiving adjuvant endocrine therapy with an aromatase inhibitor combined with pharmacologic ovarian suppression using a gonadotropin-releasing hormone analog. Potential participants will be identified during routine outpatient visits at participating oncology centers in Brazil. Participants will be classified according to World Health Organization body mass index categories and analyzed in two groups: normal body mass index and overweight or obesity.

Beschrijving

Inclusion Criteria:

Female sex. Age 18 years or older. Histologically confirmed hormone receptor-positive invasive breast cancer, defined as estrogen receptor-positive and/or progesterone receptor-positive disease, regardless of human epidermal growth factor receptor 2 status.

Premenopausal status at the initiation of ovarian suppression, as determined by menstrual history and/or laboratory criteria according to medical assessment.

Indication for adjuvant treatment with an aromatase inhibitor (anastrozole, letrozole, or exemestane) combined with pharmacologic ovarian suppression using a gonadotropin-releasing hormone analog.

Continuous use of an aromatase inhibitor and a gonadotropin-releasing hormone analog for at least 3 months before the primary study assessment.

Documented body mass index at enrollment. Ability to understand the study information and provide written informed consent.

Exclusion Criteria:

Postmenopausal status at the initiation of endocrine therapy. Known endocrine disorders that may interfere with the production or metabolism of sex steroids.

Concomitant use of medications known to interfere with estradiol metabolism or measurement, including systemic corticosteroids at supraphysiologic doses.

Metastatic disease at enrollment. Technical or logistical inability to undergo serum estradiol measurement using an ultrasensitive laboratory method.

Concurrent participation in another clinical study that may interfere with the hormonal outcomes evaluated in this study.

Studie plan

Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.

Hoe is de studie opgezet?

Ontwerpdetails

  • Observatiemodellen: COHORT
  • Tijdsperspectieven: PROSPECTIVE

Cohorten en interventies

Groep / Cohort
Normal BMI

Premenopausal participants with hormone receptor-positive breast cancer receiving an aromatase inhibitor and pharmacologic ovarian suppression who have a body mass index within the normal range according to World Health Organization criteria.

Overweight or Obesity

Premenopausal participants with hormone receptor-positive breast cancer receiving an aromatase inhibitor and pharmacologic ovarian suppression who are classified as having overweight or obesity according to World Health Organization body mass index criteria.

Wat meet het onderzoek?

Primaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Percentage of Participants With Inadequate Estrogen Suppression
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

Percentage of participants with a serum estradiol concentration greater than 2.72 pg/mL after approximately 3 months of treatment with an aromatase inhibitor and pharmacologic ovarian suppression. Serum estradiol will be measured using an ultrasensitive laboratory method. The percentage will be calculated as the number of participants with estradiol greater than 2.72 pg/mL divided by the number of evaluable participants in each body mass index group, multiplied by 100. Results will be compared between participants with normal body mass index and those with overweight or obesity.

At 3 months of treatment (visit window: ±14 days)

Secundaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Serum Estradiol Concentration by Body Mass Index Category
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

Serum estradiol concentration, measured in pg/mL using an ultrasensitive laboratory method, will be summarized and compared across body mass index categories.

At 3 months of treatment (visit window: ±14 days)
Correlation Between Body Mass Index and Serum Estradiol Concentration
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

The relationship between body mass index, measured in kg/m², and serum estradiol concentration, measured in pg/mL, will be assessed using Spearman's correlation coefficient. The coefficient ranges from -1 to 1, with higher positive values indicating a stronger positive association.

At 3 months of treatment (visit window: ±14 days)
Body Mass Index Cutoff Associated With Inadequate Estrogen Suppression
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

A potential body mass index cutoff, measured in kg/m², associated with serum estradiol greater than 2.72 pg/mL will be explored using receiver operating characteristic curve analysis. The analysis will include estimation of the area under the curve, sensitivity, and specificity of the identified cutoff.

At 3 months of treatment (visit window: ±14 days)
Association Between Clinical Characteristics and Inadequate Estrogen Suppression
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

Associations between prespecified clinical characteristics and inadequate estrogen suppression, defined as serum estradiol greater than 2.72 pg/mL, will be evaluated using binary logistic regression. Results will be reported as odds ratios with 95% confidence intervals. Evaluated characteristics may include body mass index, age, previous chemotherapy, endocrine treatment characteristics, concomitant medications, and other clinically relevant potential confounders collected according to the protocol.

At 3 months of treatment (visit window: ±14 days)
Serum Estradiol Outcomes in Prespecified Clinical Subgroups
Tijdsspanne: At 3 months of treatment (visit window: ±14 days)

Serum estradiol concentration and the percentage of participants with estradiol greater than 2.72 pg/mL will be explored in subgroups defined by previous chemotherapy, physical activity, and use of glucagon-like peptide-1 receptor agonists. These analyses are exploratory.

At 3 months of treatment (visit window: ±14 days)

Medewerkers en onderzoekers

Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.

Sponsor

Medewerkers

Onderzoekers

  • Hoofdonderzoeker: Luísa C.D.F Costa, MD, Institute of Cancer of São Paulo
  • Hoofdonderzoeker: Renata C bonadio, D'Or Institute for Research and Education (IDOR)

Publicaties en nuttige links

De persoon die verantwoordelijk is voor het invoeren van informatie over het onderzoek stelt deze publicaties vrijwillig ter beschikking. Dit kan gaan over alles wat met het onderzoek te maken heeft.

Algemene publicaties

Studie record data

Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.

Bestudeer belangrijke data

Studie start (Geschat)

3 september 2026

Primaire voltooiing (Geschat)

30 december 2026

Studie voltooiing (Geschat)

30 mei 2027

Studieregistratiedata

Eerst ingediend

16 september 2026

Eerst ingediend dat voldeed aan de QC-criteria

16 september 2026

Eerst geplaatst (Werkelijk)

22 september 2026

Updates van studierecords

Laatste update geplaatst (Werkelijk)

22 september 2026

Laatste update ingediend die voldeed aan QC-criteria

16 september 2026

Laatst geverifieerd

1 september 2026

Meer informatie

Termen gerelateerd aan deze studie

Andere studie-ID-nummers

  • SIMPEC-ESTRADIOL-001

Plan Individuele Deelnemersgegevens (IPD)

Bent u van plan om gegevens van individuele deelnemers (IPD) te delen?

NEE

Beschrijving IPD-plan

Individual participant data will not be made publicly available under the current protocol because the informed consent and data governance procedures do not provide for external sharing of individual-level clinical and laboratory data. Study findings will be disseminated in aggregate form to protect participant privacy and confidentiality and to comply with applicable ethical requirements and Brazilian data protection legislation.

Informatie over medicijnen en apparaten, studiedocumenten

Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel

Nee

Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct

Nee

Deze informatie is zonder wijzigingen rechtstreeks van de website clinicaltrials.gov gehaald. Als u verzoeken heeft om uw onderzoeksgegevens te wijzigen, te verwijderen of bij te werken, neem dan contact op met register@clinicaltrials.gov. Zodra er een wijziging wordt doorgevoerd op clinicaltrials.gov, wordt deze ook automatisch bijgewerkt op onze website .