NCT04570956

Oral Tamoxifen vs. TamGel vs. Control in Women With Atypical Hyperplasia, Lobular Carcinoma In Situ, or Increased Breast Cancer Risk

Phase IIB Randomized Trial of Oral Tamoxifen vs. Topical 4-hydroxytamoxifen Gel vs. Control in Women With Atypical Hyperplasia, Lobular Carcinoma in Situ, or Increased Breast Cancer Risk

• Status: Terminated
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 65 (actual)
• Sponsor: Mayo Clinic · Academic / Other
• Sex: Female
• Age: 18 Years – 80 Years
• Healthy volunteers: Not accepted

Summary

The investigators plan to prospectively study breast tissue changes after a short course of Tamoxifen (Tam).

Detailed description

Women with atypical hyperplasia (AH) and lobular carcinoma in situ (LCIS) are at increased risk of breast cancer (BC) (\~1-2 % per year). Over two decades ago, placebo-controlled randomized trials established that oral tamoxifen (20 mg/day) reduces breast cancer risk by 50% in generally defined high risk women, with \~70% reduction in women at high risk specifically due to atypical hyperplasia.\[1\] Years later, the side effects and toxicity of oral tamoxifen at 20 mg/day remain a significant barrier to its uptake and longterm compliance.\[2, 3\] To address the issue of toxicity, two main strategies have been pursued: 1) using a lower dose of oral tamoxifen, and 2) using a topical formulation of tamoxifen to avoid systemic side effects. The investigators will perform a prospective study of women with AH or LCIS who will take a short course of prevention therapy; breast tissue samples will be evaluated pre- and post-therapy to identify and evaluate very early biomarkers of response. The overall goal of the study is to evaluate short-term changes in background breast tissue induced by either low-dose oral tamoxifen or topical 4-OHT gel in women with AH or LCIS.

Conditions

• Breast Atypical Hyperplasia
• Breast Lobular Carcinoma in Situ
• Breast Atypical Lobular Hyperplasia
• Breast Carcinoma

Interventions

Type	Name	Description
DRUG	Tamoxifen	Oral Tamoxifen 10 mg/day
DRUG	Topical 4-OHT( 4-hydroxytamoxifen)gel 4 mg/each breast/day	Topical 4-OHT (4-hydroxytamoxifen) gel 4 mg/each breast/day
DRUG	Placebo	placebo pill or placebo gel
OTHER	Questionnaire Administration	Ancillary studies

Timeline

• Start date: 2021-07-26
• Primary completion: 2024-10-15
• Completion: 2024-10-15
• First posted: 2020-09-30
• Last updated: 2026-01-23

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study