Molecular markers, pathology, and ultrasound features of invasive breast cancer.

Introduction: Ultrasound is commonly used in breast cancer screening and diagnosis. The use of ultrasound features to predict the subtypes of invasive breast cancer is of great clinical significance, since it facilitates a fast and early diagnosis and treatment. The correlation between breast lesion ultrasound features and the breast cancer subtypes requires further investigation.

Methods: 388 patients with invasive breast cancer were retrospectively analyzed by two sonographers. The tumor size, shape, margin, echogenicity, echotexture, posterior echo attenuation microcalcification, and blood vessel density were recorded. The correlation between the tumor ER, PR, HER2, and Ki67 status, the molecular subtypes, and the ultrasound features was analyzed using the chi-square test, Fisher's exact test, and multiple logistic regression.

Results: ER and PR positivity were correlated with a low histologic grade, lymph node metastasis, and smaller-sized tumors. A hyperechoic or a mixed echogenicity was rare in the tumors of all groups but was enriched in the ER and PR tumors (9.57% and 7.64%, respectively, p < 0.01). A high percentage of posterior echo attenuation was found in the Ki67 low (53.94%) and ER+ (51.28%) tumors. Furthermore, heterogeneous and microcalcifications were enriched in HER2-positive tumors. In terms of the molecular subtypes, the luminal A subtype group had the lowest lymph node positivity and the smallest primary tumor size. The luminal B subtype had the lowest percentage of hyperechoic or mixed tumors. The HER2 subtype was positively correlated with microcalcification. Finally, TNBC showed the highest percentage of hyperechoic or mixed tumors and the lowest percentage of posterior echo attenuation and microcalcification.

Conclusion: Tumor pathologic and ultrasound features were correlated with invasive breast tumor molecular marker positivity and its molecular subtypes.