The Relationship of Endometrial Pathologies with Endometrial Thickness and Inflammatory Markers in Breast Cancers Using Tamoxifen

Abstract Purpose: Some proliferative and neoplastic changes can be seen in the endometrium of breast cancers using tamoxifen adjuvant therapy(TMX-BC). Identifying risk groups is crucial, but methods and frequency of endometrial follow-ups is still controversial. This study was aimed to investigate the clinical, ultrasonographic, and inflammatory factors to differentiate pathological endometrium in TMX-BC.Methods: This study retrospectively analyzed endometrial biopsy results of TMX-BC(n:361). Normal endometrium (Group I, n:237) and pathological endometrium(Group II, n:124) were compared for clinical, ultrasonographic, and inflammatory features. Neutrophil and platelet to lymphocyte ratio(NLR; PLR), mean platelet volume (MPV), platelet distribution width(PDW), red blood cell distribution width(RDW), and lymphocyte monocyte ratio(LMR) were the inflammatory markers. Results: The majority of TMX-BC with endometrial biopsy were asymptomatic (72.6%) and had normal endometrium (65.7%). Pathologic endometrium included endometrial polyp(31.9%), endometrial hyperplasia(1.7%), and endometrial cancer(0.8%). Duration of tamoxifen, cancer stage, vaginal bleeding, and menopause was similar in Group I and Group II (p>0.05). Group II had increased endometrial thickness (11.22±5.44mm) compared to Group I (8.51±3.43mm). Group II had higher RDW and PDW than Group I(p<0.05). Endometrial thickness ≥10 mm had significant diagnostic potential in postmenopausal women(AUC:0.676, p:0.000, CI:0.5-0.7), but not in premenopause. Conclusion: PDW and RDW may be promising markers for pathologicalendometrium differentiation, but these preliminary findings should be validated by clinical studies. Measurement of endometrial thickness in asymptomatic patients may predict high-risk women with pathologicalendometrium in postmenopausal women. Further studies are needed in premenopausal women and those using tamoxifen for more than five years.