Massively Invasive Ductal Breast Cancer: Association Between Mammographic Features and the HER2-enriched Molecular Subtype

Objectives: This study aimed to determine whether there were differences in mammographic characteristics (mass size and margin of the mass) between the HER2-enriched and non-HER2-enriched molecular subtypes of breast cancer.Methods: A total of 142 individuals with mammographically verified masses and histopathologically diagnosed invasive ductal breast cancer were detected (HER2-enriched: n=29; HER2 non-enriched: n=113).Mammographic features related to HER2 molecular subtype were analyzed.According to the TNM staging criteria, patients with masses on mammography were divided into ≤2 cm (T1) and >2 cm (T2 and T3) groups.The margin characteristics of the mass detected by mammography were divided into spiculated and nonspiculated groups.Results: Histopathological sampling was performed on the lesions of 142 patients with breast cancer who had mass lesions associated with invasive ductal carcinoma on mammography; 29/142 (20.4%) were HER2-enriched and 113/142 (79.5%) were non-HER2-enriched.On univariate analysis; HER2-enriched molecular subtype rates were significantly higher in tumor size ≤2 cm [17/60 (28.3%)] than in those >2 cm [12/82 (14.6%)] (p=0.007) and HER2-enriched molecular subtype rates were significantly higher in nonspiculated lesions [20/61 (32.7%)] than in spiculated lesions [9/81 (11.1%)] (p<0.001).No significant associations were observed between patients age and HER2-subtypes. Conclusion:Small tumor sizes and non-spiculated masses were more likely to be HER2 molecular subtype.This study presents a predictive model that combines tumor size and nonspiculated mass mammographic characteristics.This model has the potential to determine the HER2-enriched subtype of breast cancer before surgery.