Tamoxifen use and risk of endometrial pathology in breast cancer patients: A Prospective cohort study
1Babar Shahzad, 2SOMER MASOOD, 3MUHAMMAD HARIS JANJUA, 4Dr. Muhammad Waqas Khan, 5JAWAD AHMED, 6MAAZ HASSAN.
Submission: 10 February 2026 | Acceptance: 20 March 2026 | Publication: 15 April 2026,
1Services Hospital Lahore.
2Associate Professor, Department of General Surgery,West Surgical Ward, Mayo Hospital Lahore, King Edward Medical University, Lahore
3Assistant Professor, Department of General Surgery, East Surgical Ward, Mayo Hospital,King Edward Medical University, Lahore
4Assistant Professor in Histopathology, Pathology Department College:Pak international medical College,Peshawar
5Fellow Breast Oncology , Department of General Surgery,West Surgical Ward, Mayo Hospital, King Edward Medical University, Lahore
6Post Graduate Resident, West Surgical Ward, Mayo Hospital Lahore, King Edward Medical University, Lahore
Abstract
Background:
There is significant evidence implicating the association of tamoxifen with endometrial pathologies leading to various gynecological symptoms. Therefore surveillance is needed for possible adverse effects of tamoxifen therapy on uterus but data regarding surveillance of endometrial symptoms is scarce.
Objective:
To investigate the effects of tamoxifen on uterine endometrium in preventive setting.
Methods:
This prospective cohort study conducted at Mayo Hospital , Lahore between November 2019 to November 2024 that included female breast cancer patients who underwent mastectomy, aged 30-70 years undergoing tamoxifen therapy.Self- administered questionnaire was used for data collection. A non-probability consecutive sampling technique was used to recruit eligible patients. Baseline demographic data, gynecological symptoms, and endometrial thickness measurements were collected at 2.5 years and 5 years. Statistical analyses were conducted using SPSS (version 25), with p < 0.05 considered statistically significant.
Results :
The mean age of the patients was 55 years and mean BMI was 27kg/m2. The mean endometrial thickness at 2.5 years and 5 years was 6 mm and 4.3 mm respectively. The p-value for endometrial thickness at 2.5 years and 5 years was 1 and 0.0001, respectively.
Endometrial samples were taken in 160(30.4%) patients,
and the average duration for referral was 2.5 years.
Hysterectomy was performed on 3(0.4%) patients and none of them had endometrial carcinoma on biopsy.
Conclusion:
Our study reinforces the need for individualized monitoring strategies for tamoxifen-treated breast cancer patients, particularly premenopausal women. While routine gynecological assessments remain the standard of care, clinicians should recognize the potential for increased endometrial pathology in this population
Keywords:
Frequency, gynecological symptoms, breast cancer, tamoxifen.