Trial · NCT03346200

Low Dose Tamoxifen for Mammographic Density Reduction

NCT03346200, Phase 2, Completed, Per Hall; results first posted 2025-03-07

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Low Dose Tamoxifen for Mammographic Density Reduction. Trials, record NCT03346200. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03346200

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Trial

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

Title: Low Dose Tamoxifen for Mammographic Density Reduction
NCT number: NCT03346200
Status: Completed
Phases: Phase 2
Enrollment: 1,440 participants, actual
Lead sponsor: Per Hall
Conditions: Risk Reduction, Mammographic Density Reduction
Interventions: Tamoxifen Oral Tablet, Placebo Oral Tablet
First posted: 2017-11-17
Last updated: 2025-03-07
Results first posted: 2025-03-07

Source ClinicalTrials.gov

Registered outcomes3

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

List	Outcome	Time frame	Description
Primary	Mammograpic Density Change	6 months treatment	Change in mammography density. In particular, we will test for noninferiority in the proportion of women in the intervention arms (placebo, 1 mg, 2.5 mg, 5 mg, 10 mg) who have a density reduction as great as or greater (after 6 months) than the median density reduction in the 20 mg arm.
Secondary	Level of Side Effects	From baseline (7-1days before first tablet) up to 6 months or day of discontionuation (prior to 6 months)	Assess the level of side effects in the intervention arms compared to the 20 mg arm. Symptoms are reported on a 5-graded Likert score scale in a 48-item symptom questionnaire at Baseline and at End of treatment ( End of treatment= full-filled the 6 month treatment or at time of discontinuation prior to 6 months). The outcome measure is based on the sum in Likert score of five symptoms ('hot flashes', 'cold sweats', 'night sweats', 'vaginal discharge' and 'muscle cramps') which were found to have a significant change from start to the end of treatment in both pre- and postmenopausal women when contrasting the effect of 20 mg tamoxifen compared to women on placebo. The maximum/minimum range of change per symtom is 4 steps increase or decrease. Accordingly, in the Top-5 symtoms the maximum/minimum range is +/- 20. Higher scores mean a worse outcome.
Secondary	Drop Out Level	From initiation of treatment (first tablet) up to 6 months of planned treatment (last tablet)	Assess the level of drop out in the intervention arms compared to the 20 mg arm

Source ClinicalTrials.gov

Outcomes3

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

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Mammograpic Density Change	6 months treatment		Percentage of change	MEAN
SECONDARY	Level of Side Effects	From baseline (7-1days before first tablet) up to 6 months or day of discontionuation (prior to 6 months)	In all 1175 women, whereof 454 (39%) premenopausal and 721 (61%) postmenopausal, constitute the per protocol population which fulfilled teh 48-item Symptom questionnaire at Baseline and at End of treatment (6month or at time of Early termination)	Likert score change in Top5 Symptoms	MEAN
SECONDARY	Drop Out Level	From initiation of treatment (first tablet) up to 6 months of planned treatment (last tablet)	ITT population	Participants	COUNT_OF_PARTICIPANTS

Source ClinicalTrials.gov

Results by group18

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

Outcome	Group	Value	Spread	Units
Mammograpic Density Change	20 mg Tamoxifen	-9.6	95% Confidence Interval -14.8 to -4.5	Percentage of change
Mammograpic Density Change	10 mg Tamoxifen	-6.8	95% Confidence Interval -11.8 to -1.7	Percentage of change
Mammograpic Density Change	5 mg Tamoxifen	-1.0	95% Confidence Interval -6.2 to 4.1	Percentage of change
Mammograpic Density Change	2.5 mg Tamoxifen	-6.9	95% Confidence Interval -12.1 to -1.8	Percentage of change
Mammograpic Density Change	1 mg Tamoxifen	-1.0	95% Confidence Interval -6.1 to 4.1	Percentage of change
Mammograpic Density Change	0 mg Tamoxifen	0.1	95% Confidence Interval -4.9 to 5.1	Percentage of change
Level of Side Effects	20 mg Tamoxifen	2.71	95% Confidence Interval 2.29 to 3.13	Likert score change in Top5 Symptoms
Level of Side Effects	10 mg Tamoxifen	2.97	95% Confidence Interval 2.50 to 3.45	Likert score change in Top5 Symptoms
Level of Side Effects	5 mg Tamoxifen	2.52	95% Confidence Interval 2.07 to 2.97	Likert score change in Top5 Symptoms
Level of Side Effects	2.5 mg Tamoxifen	2.39	95% Confidence Interval 1.94 to 2.85	Likert score change in Top5 Symptoms

1 to 10 of 18Source ClinicalTrials.gov

See all 18 results by group

Participant flow18

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

Period	Milestone	Group	Participants
Overall Study	STARTED	20 mg Tamoxifen	241
Overall Study	STARTED	10 mg Tamoxifen	243
Overall Study	STARTED	5 mg Tamoxifen	240
Overall Study	STARTED	2.5 mg Tamoxifen	235
Overall Study	STARTED	1 mg Tamoxifen	239
Overall Study	STARTED	0 mg Tamoxifen	242
Overall Study	COMPLETED	20 mg Tamoxifen	171
Overall Study	COMPLETED	10 mg Tamoxifen	167
Overall Study	COMPLETED	5 mg Tamoxifen	157
Overall Study	COMPLETED	2.5 mg Tamoxifen	159

1 to 10 of 18Source ClinicalTrials.gov

See all 18 participant flow

Adverse events72

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	Events
other	Hot flush	Endocrine disorders	20 mg Tamoxifen	24	241	34
other	Hot flush	Endocrine disorders	10 mg Tamoxifen	32	243	38
other	Hot flush	Endocrine disorders	5 mg Tamoxifen	26	240	47
other	Hot flush	Endocrine disorders	2.5 mg Tamoxifen	25	235	32
other	Hot flush	Endocrine disorders	1 mg Tamoxifen	20	239	21
other	Hot flush	Endocrine disorders	0 mg Tamoxifen	13	242	21
other	Night sweats	Endocrine disorders	20 mg Tamoxifen	19	241	42
other	Night sweats	Endocrine disorders	10 mg Tamoxifen	21	243	24
other	Night sweats	Endocrine disorders	5 mg Tamoxifen	24	240	49
other	Night sweats	Endocrine disorders	2.5 mg Tamoxifen	22	235	33

1 to 10 of 72Source ClinicalTrials.gov

See all 72 adverse events

Adverse event totals18

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	20 mg Tamoxifen	0	241
Total, all-cause mortality	10 mg Tamoxifen	0	243
Total, all-cause mortality	5 mg Tamoxifen	0	240
Total, all-cause mortality	2.5 mg Tamoxifen	0	235
Total, all-cause mortality	1 mg Tamoxifen	0	239
Total, all-cause mortality	0 mg Tamoxifen	0	242
Total, other adverse events	20 mg Tamoxifen	74	241
Total, other adverse events	10 mg Tamoxifen	70	243
Total, other adverse events	5 mg Tamoxifen	63	240
Total, other adverse events	2.5 mg Tamoxifen	65	235

1 to 10 of 18Source ClinicalTrials.gov

See all 18 adverse event totals

Papers6

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
33734864	RESULT	PubMed
36637153	DERIVED	PubMed
37149701	DERIVED	PubMed
38554131	DERIVED	PubMed
39593191	DERIVED	PubMed
42720596	DERIVED	PubMed

Grants0

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.

None in this release.

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/NCT03346200

GET https://conductscience.org/api/trials/v1/NCT03346200/events?page=2

API reference For AI assistants