Utility of Ultrasound Imaging Features in Diagnosis of Breast Cancer

Abstract

Background Currently, breast cancer (BC) is considered one of the most prevalent cancer worldwide in women and represents a global health challenge. Early diagnosis is the keystone in the management of BC patients. This study aims to assess the utility of ultrasonography (US) features of malignancy in the diagnosis of BC. Methods This retrospective cross-sectional study involved the electronic records of 326 female patients who were diagnosed with BC. A cross-tabulation test was performed to identify the association between the presence of each US feature (yes/no), and the final US diagnosis (benign/malignant). The strength of association of each feature was measured using the odds ratio (OR) which was assumed to be significant when > 1, with a 95% confidence interval (CI). Results The mean age of the female patients involved in this study was 45.36 ±12.16 years old (range, 17-90 years). Cross-tabulation test showed a significant association between the malignancy tumor and the irregular shape of the lesion (p < 0.001, OR=7.162, CI 2.726-18.814), non-circumscribed margins (p < 0.001, OR = 9.031, CI 3.200-25.489), tissue distortion (p < 0.001, OR = 18.095, CI 5.944-55.091), and the lymph node enlargement (p < 0.001, OR = 5.705, CI 2.332-13.960). Conclusion US imaging features of malignancy have a high sensitivity and positive predictive value for detection of the BC. However, the specificity of breast US imaging features is much lower because of the overlapping features in benign and malignant breast lesions. Breast lesions with an irregular shape, not circumscribed irregular or spiculated margins, hypo-echogenicity, tissue distortion, and those with lymphadenopathy have the highest likelihood of malignancy despite the low specificity. US is a highly valuable, safe, and affordable imaging modality with high diagnostic accuracy for BC.

Keywords: breast cancer; hypo-echogenicity of the mass; irregular shape of the mass; lymphadenopathy; specificity of ultrasound imaging features; spiculated margins of the mass; tissue distortion.

Figure 1. ultrasound images of two different patients showing a) irregular shape, partially ill-defined spiculated margin, hypoechogenic breast lesion with posterior acoustic shadowing, b) irregular shape, partially ill-defined spiculated margin, hypoechogenic breast lesion with posterior acoustic shadowing. Both lesions were malignant lesions as proved by histopathology examinations.

Figure 2. Receiver operating characteristic (ROC) curve shows the area under the curve (AUC) of each feature of BC and revealed that AUC of tissue distortion= 0.809, AUC of lymphadenopathy=0.658, AUC of irregular shape =0.639, AUC of non-circumscribed = 0.629, AUC of speculated margins= 0.574, AUC of hypo-echogenicity=0.520.