Determining a Treatment Threshold Value for Endometrial Thickness in Women with Breast Cancer Receiving Tamoxifen.

Background: Breast cancer is a prevalent malignancy in women that often requires endocrine treatment, such as tamoxifen, which is known to affect endometrial thickness and pose risks of endometrial pathologies.

Objective: This study aimed to determine a clinically relevant threshold for transvaginal ultrasound-measured endometrial thickness in breast cancer patients receiving tamoxifen therapy and assess its predictive value for endometrial pathologies.

Methods: We analyzed a total of 205 endometrial biopsies from women dichotomized into premenopausal and postmenopausal groups. We assessed the clinical and pathological characteristics in relation to the presence of endometrial pathologies, employing receiver operating characteristic (ROC) curves to evaluate the predictive value of endometrial thickness as a diagnostic marker.

Results: Among the study cohort, 11.71% of patients were diagnosed with endometrial hyperplasia, and 3.90% had endometrial cancer. Our findings indicate that women with endometrial pathologies exhibited significantly greater endometrial thickness (P<0.001) in both premenopausal and postmenopausal cohorts. Notably, demographic and clinical factors including age, body mass index, gravidity, parity, comorbidities, duration of tamoxifen use, and abnormal vaginal bleeding did not differ significantly between groups with or without pathology. The ROC analysis yielded an area under the curve (AUC) of 0.845 for premenopausal and 0.759 for postmenopausal patients, establishing cutoff values of 0.95 cm and 0.55 cm, respectively.

Conclusion: Our research confirms that endometrial thickness serves as a significant clinical indicator for diagnosing endometrial pathologies in breast cancer patients receiving tamoxifen therapy, underscoring the necessity for risk-based strategies to monitor patients with thickened endometria and advocating for timely hysteroscopic intervention when warranted.