Diagnostic Efficiency of Endometrial Sampling Methods and Risk Factors for Endometrial Carcinoma and Precursor Lesions in Premenopausal Women

<b>Objective:</b> Accurate preoperative differentiation between benign endometrial conditions and malignancies is essential for guiding therapeutic interventions. However, high-quality evidence regarding the diagnostic accuracy of endometrial sampling techniques remains insufficient. This study aimed to evaluate the diagnostic efficiency of hysteroscopically directed biopsy, Pipelle suction curettage, and dilatation and curettage (D&C) for detecting endometrial hyperplasia or carcinoma in premenopausal women and to identify associated risk factors. <b>Methods:</b> A retrospective single-center cohort analysis was conducted on 2054 premenopausal women. Demographic, clinical, and obstetric data, along with biopsy techniques and histopathological findings, were recorded. Diagnostic accuracy of biopsy methods was compared against definitive surgical pathology. <b>Results:</b> The prevalence of endometrial hyperplasia and carcinoma was 5.6% and 1.0%, respectively. Hysteroscopically directed biopsy demonstrated superior diagnostic accuracy (AUC 0.957) compared to D&C (AUC 0.909) and Pipelle suction curettage (AUC 0.858). Sensitivity was highest for hysteroscopically directed biopsy (91.3%), followed by D&C (82.0%) and Pipelle suction curettage (71.7%), while specificity remained excellent across all methods (<i>p</i> < 0.001). Elevated BMI increased the risk of hyperplasia or carcinoma by 1.05 times per unit increase (OR = 1.054, <i>p</i> = 0.005), while hypertension nearly doubled the risk (OR = 1.99, <i>p</i> = 0.009). Multiparity showed protective effects, reducing risk with each additional delivery (OR = 0.877, <i>p</i> = 0.029). <b>Conclusions:</b> Hysteroscopically directed biopsy provides superior diagnostic accuracy for detecting endometrial hyperplasia and carcinoma in premenopausal women. Hypertension and elevated BMI increase risk, while multiparity offers protective benefits.