Effect of Metformin on Endometrial Thickness in Postmenopausal Breast Cancer Patients Receiving Tamoxifen

Uruk University60 enrolled

Overview

The goal of this clinical trial is to learn if metformin can reduce the increase in endometrial thickness caused by tamoxifen in women with estrogen-positive breast cancer taking tamoxifen for more than 1 year. It will also learn about the safety of taking metformin with tamoxifen. The main questions it aims to answer are: 1. Does metformin decrease endometrial thickness in women receiving tamoxifen? 2. What medical problems do participants have when taking metformin with tamoxifen? Researchers will compare tamoxifen plus metformin to tamoxifen plus placebo to see if metformin works to reduce endometrial thickness compared to placebo patients. Participants will: 1. Take metformin daily along with tamoxifen, or take tamoxifen with placebo. 2. Acquire baseline assessment and then visit the clinic at 3 months, 6 months, 9 months and 12 months for checkups and trans abdominal ultrasound test for endometrial thickness, and to be monitored for any side effects or complications.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

Conditions

Breast Cancer Endometrial Hyperplasia and Endometrial Cancers

MetfominDRUG

Metformin Tab. 500mg twice daily for 12 months (titrated to tolerance if needed).

tamoxifenDRUG

Standard prescribed oncological dose.

Placebo matching MetforminDRUG

An inert, film-coated tablet identical in appearance and packaging to metformin 500 mg (same size, shape, color, coating, weight, and dosing schedule), manufactured without active ingredient using standard excipients (e.g., microcrystalline cellulose, starch/croscarmellose, povidone, magnesium stearate) and identical film coat (e.g., hypromellose, polyethylene glycol, titanium dioxide). Packaged in sealed blisters to minimize odor/taste cues. Dispensed by the investigational pharmacy per randomization; to be taken twice daily"

Eligibility

Sex: FEMALE

Medical Language ↔ Plain English

Inclusion Criteria: * Postmenopausal Female patients (amenorrhea ≥ 12 months). * Histologically proven (Estrogen-positive) breast cancer. * Completed all required surgery and/or chemotherapy (if indicated) * On adjuvant tamoxifen for at least 1 year. * Accepts to enroll in the study Exclusion Criteria: * Refusing to enroll in the study * Ongoing or History of: endometrial or ovarian malignancy * Concurrent hormonal therapy that might affect endometrial thickness * Concurrent Diabetes mellitus in which metformin is prescribed. * Known hypersensitivity or severe intolerance to metformin

Outcomes

Primary Outcomes

Change in endometrial thickness

Endometrial thickness will be measured using transabdominal ultrasound (in millimeters) by a trained radiologist. The primary outcome is the difference in endometrial thickness between the metformin plus tamoxifen group and the placebo plus tamoxifen control group.

Time frame: Baseline, 3 months, 6 months, 9 months, and 12 months from enrollment