A comparative study of subjective and objective techniques using two-dimensional ultrasound in the preoperative assessment of cervical and myometrial invasion in patients with endometrial cancer

Abstract

CONTEXT: Endometrial cancer is the third most common malignancy of the female genital tract in the Philippines, following cervical and ovarian cancer. Ultrasound as the first line in imaging has a major role in preoperative treatment and planning. AIMS: To compare the diagnostic accuracy of subjective versus objective ultrasound measurement techniques in detecting cervical stromal invasion (CSI) and deep myometrial invasion (MI). MATERIALS AND METHODS: Fifty-seven patients were enrolled in this cross-sectional study. Deep MI and CSI were evaluated both subjectively and objectively by measuring tumor-free distance (TFD), distance from the outer cervical os to lowest edge of the tumor border (Dist-OCO), and distance from the internal cervical os to caudal tumor border (Dist-ICO). Histopathological result used as the gold standard. RESULTS: Subjective assessment for deep (MI) had 79.3% sensitivity, 82.1% specificity, 82.1% positive predictive value (PPV), 82.1% negative predictive value (NPV), and 80.7%. Subjective assessment for CSI had a sensitivity, specificity, PPV, NPV, and overall accuracy of 80%, 90.4%, 44.4%, 97.9%, and 89.5%. Objective measurement (TFD ≤0.8 cm) to detect deep MI had 86.2% sensitivity, 57.1% specificity, 67.4% PPV, 80% NPV, and 71.9% overall accuracy. Adjusting TFD cutoff to 0.65 increased to 71.4% specificity, making it comparable with subjective assessment. Dist-OCO (≤2.1 cm) yielded 100% sensitivity, 86.3% specificity, 30% PPV, 100% NPV, and 87% overall accuracy. Dist-ICO was first used in this study, hence no cutoff yet. By using receiver operating characteristics, cutoff was 0.45 cm, which yielded a 60% sensitivity and 92% specificity (area under the curve 0.731, P = 0.09). CONCLUSIONS: Subjective assessment of CSI and deep MI performs better than objective measurement techniques. TFD and Dist-OCO as the objective measurements showed clinically comparable accuracy to subjective assessment by an expert. Dist-ICO needs to be validated to a larger population to determine its clinical value in predicting CSI.