Trial · NCT00764322

Studying Blood Samples From Women With Breast Cancer or Ductal Carcinoma In Situ Who Are Receiving Tamoxifen

NCT00764322, Phase 2, Completed, UNC Lineberger Comprehensive Cancer Center; results first posted 2017-07-02

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Studying Blood Samples From Women With Breast Cancer or Ductal Carcinoma In Situ Who Are Receiving Tamoxifen. Trials, record NCT00764322. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00764322

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Studying Blood Samples From Women With Breast Cancer or Ductal Carcinoma In Situ Who Are Receiving Tamoxifen
NCT number: NCT00764322
Status: Completed
Phases: Phase 2
Enrollment: 501 participants, actual
Lead sponsor: UNC Lineberger Comprehensive Cancer Center
Conditions: Breast Cancer, Menopausal Symptoms
Interventions: tamoxifen citrate, gene expression analysis, pharmacogenomic studies, questionnaire administration, quality-of-life assessment
First posted: 2008-10-02
Last updated: 2017-08-01
Results first posted: 2017-07-02

Source ClinicalTrials.gov

Registered outcomes6

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	4 months	Measurements of plasma concentrations of the key active metabolite of tamoxifen, endoxifen, were measured at baseline and after 4 months of treatment; The most common CYP2D6 alleles have been grouped by functional activity classifications with descending activity: ultra-rapid (UM), extensive (EM), intermediate (IM) or poor (PM) metabolism. A given patient has two alleles, giving them 10 possible allelic combinations, or diplotypes (UM/UM, UM/EM, EM/EM, etc.). These diplotypes are collapsed into four phenotypes, UM, EM, IM or PM.
Secondary	Number of Participants With Pulmonary Embolism (PE), Deep Vein Thrombosis (DVT), Stroke, and/or Endometrial Cancer	Approximately ten months from registration to last follow-up	The doubling of tamoxifen dose is defined as "unacceptable" (i.e., not tolerable) if the prevalence of Pulmonary embolism (PE), Deep vein thrombosis (DVT), stroke, or endometrial cancer, either individually or in any combination, is greater than 2%.
Secondary	Change in Median Endoxifen Concentrations to Determine Feasibility of Obtaining Pharmacogenomic Information From Patients in the Clinical Setting and Using it to Guide Changes in Therapy	Baseline and 4 months after dose increase	If the key active tamoxifen metabolite, endoxifen, could be significantly increased by genotype-guided tamoxifen dosing in patients with intermediate CYP2D6 metabolism (by increasing tamoxifen dosing based on CYP2D6 genotype), then the study would be deemed feasible and the accrual expanded.
Secondary	CYP2D6 Allele Frequencies and Endoxifen Levels Among African-American Women Taking Tamoxifen Citrate	baseline	Mean endoxifen levels by CYP2D6 genotype among African Americans. Measurements of plasma concentrations of the key active metabolite of tamoxifen, endoxifen, were measured at baseline.The most common CYP2D6 alleles have been grouped by functional activity classifications with descending activity: ultra-rapid (UM), extensive (EM), intermediate (IM) or poor (PM) metabolism. A given patient has two alleles, giving them 10 possible allelic combinations, or diplotypes (UM/UM, UM/EM, EM/EM, etc.). These diplotypes are collapsed into four phenotypes, UM, EM, IM or PM.
Secondary	Change in Plasma Endoxifen Levels After an Increase in Tamoxifen Citrate Dose From 20 mg to 40 mg Daily in Patients With Poor-metabolizing Genotypes	Baseline and 4 months after dose increase	The intrapatient change in median endoxifen levels were calculated between baseline and 4 months after the increase in dose of Tamoxifen from 20mg/day to 40 mg/day
Secondary	Patient Understanding of Pharmacogenomics	baseline	To examine patients' beliefs about how hypothetical genotype information would affect their perceived recurrence risk and benefits of tamoxifen therapy, participants were given experimentally manipulated 6 vignettes to describe hypothetical tamoxifen treatment (no or yes) and hypothetical genotype (EM, IM or PM). For each vignette, participants gave their perceived recurrence risk (RR; 0-100%)

Source ClinicalTrials.gov

Outcomes6

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	4 months	Baseline measurements are reported on all 353 subjects, while the 4 month levels are reported only for patients who completed 4 months of treatment	ng/mL	MEAN
SECONDARY	Number of Participants With Pulmonary Embolism (PE), Deep Vein Thrombosis (DVT), Stroke, and/or Endometrial Cancer	Approximately ten months from registration to last follow-up	Incidence of unacceptable adverse events among all patients who completed study	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Change in Median Endoxifen Concentrations to Determine Feasibility of Obtaining Pharmacogenomic Information From Patients in the Clinical Setting and Using it to Guide Changes in Therapy	Baseline and 4 months after dose increase	This was based on the initial 119 subjects enrolled (based on initial sample size of 100) and of those, the 89 that completed 4 months of tamoxifen therapy	ng/mL	MEDIAN
SECONDARY	CYP2D6 Allele Frequencies and Endoxifen Levels Among African-American Women Taking Tamoxifen Citrate	baseline	Only participants who self-identified as African American were included in this analysis	ng/ml	MEAN
SECONDARY	Change in Plasma Endoxifen Levels After an Increase in Tamoxifen Citrate Dose From 20 mg to 40 mg Daily in Patients With Poor-metabolizing Genotypes	Baseline and 4 months after dose increase	Analysis limited to only those subjects with the Poor Metabolizing (PM) genotype who were evaluable at baseline	ng/mL	MEDIAN
SECONDARY	Patient Understanding of Pharmacogenomics	baseline	Of 377 patients who were eligible to complete the survey, 320 patients completed the survey and 57 returned incomplete surveys	percent chance of recurrence	MEAN

Source ClinicalTrials.gov

Results by group30

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Ultra-rapid Metabolizers	Baseline endoxifen concentration	8.4	Standard Deviation 4.59	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Extensive Metabolizers	Baseline endoxifen concentration	10.00	Standard Deviation 6.00	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Intermediate Metabolizers	Baseline endoxifen concentration	7.10	Standard Deviation 4.77	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Poor Metabolizers	Baseline endoxifen concentration	3.42	Standard Deviation 2.75	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Ultra-rapid Metabolizers	4-Month endoxifen concentration	15.35	Standard Deviation 5.48	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Extensive Metabolizers	4-Month endoxifen concentration	9.30	Standard Deviation 5.03	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Intermediate Metabolizers	4-Month endoxifen concentration	10.74	Standard Deviation 7.36	ng/mL
Endoxifen Concentrations in Participants Receiving Tamoxifen Citrate Dose of 20 mg or 40 mg Stratified by the Metabolizing CYP2D6 Genotypes	Poor Metabolizers	4-Month endoxifen concentration	5.52	Standard Deviation 2.57	ng/mL
Number of Participants With Pulmonary Embolism (PE), Deep Vein Thrombosis (DVT), Stroke, and/or Endometrial Cancer	Tamoxifen 20	Pulmonary embolism (PE)	0		Participants
Number of Participants With Pulmonary Embolism (PE), Deep Vein Thrombosis (DVT), Stroke, and/or Endometrial Cancer	Tamoxifen 40	Pulmonary embolism (PE)	0		Participants

1 to 10 of 30Source ClinicalTrials.gov

See all 30 results by group

Participant flow3

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Patients Enrolled	500
Overall Study	COMPLETED	Patients Enrolled	480
Overall Study	NOT COMPLETED	Patients Enrolled	20

Source ClinicalTrials.gov

Adverse events219

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	Allergic rhinitis (including sneezing, nasal stuffiness, postnasal drip)	Immune system disorders	Ultra-rapid and Extensive Metabolizers	4	161
other	Allergic rhinitis (including sneezing, nasal stuffiness, postnasal drip)	Immune system disorders	Intermediate Metabolizers	11	290
other	Allergic rhinitis (including sneezing, nasal stuffiness, postnasal drip)	Immune system disorders	Poor Metabolizers	0	29
other	ALT, SGPT (serum glutamic pyruvic transaminase)	Investigations	Ultra-rapid and Extensive Metabolizers	3	161
other	ALT, SGPT (serum glutamic pyruvic transaminase)	Investigations	Intermediate Metabolizers	3	290
other	ALT, SGPT (serum glutamic pyruvic transaminase)	Investigations	Poor Metabolizers	0	29
other	Arthritis (non-septic)	Musculoskeletal and connective tissue disorders	Ultra-rapid and Extensive Metabolizers	0	161
other	Arthritis (non-septic)	Musculoskeletal and connective tissue disorders	Intermediate Metabolizers	5	290
other	Arthritis (non-septic)	Musculoskeletal and connective tissue disorders	Poor Metabolizers	0	29
other	AST, SGOT(serum glutamic oxaloacetic transaminase)	Investigations	Ultra-rapid and Extensive Metabolizers	5	161

1 to 10 of 219Source ClinicalTrials.gov

See all 219 adverse events

Adverse event totals9

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Ultra-rapid and Extensive Metabolizers	0	161
Total, all-cause mortality	Intermediate Metabolizers	0	290
Total, all-cause mortality	Poor Metabolizers	0	29
Total, other adverse events	Ultra-rapid and Extensive Metabolizers	149	161
Total, other adverse events	Intermediate Metabolizers	274	290
Total, other adverse events	Poor Metabolizers	26	29
Total, serious adverse events	Ultra-rapid and Extensive Metabolizers	0	161
Total, serious adverse events	Intermediate Metabolizers	3	290
Total, serious adverse events	Poor Metabolizers	0	29

Source ClinicalTrials.gov

Papers0

The papers the trial lists on ClinicalTrials.gov.

None in this release.

Grants1

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

Project	Title	Principal investigators	Organization	Funder	Fiscal years
P30CA016086	Cancer Center Support Grant	FERRIS, ROBERT L.	UNIV OF NORTH CAROLINA CHAPEL HILL	NATIONAL CANCER INSTITUTE	1985 to 2025

Source NIH RePORTER

Trial comparisons0

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

None in this release.

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT00764322

GET https://conductscience.org/api/trials/v1/NCT00764322/results?page=2

API reference For AI assistants