Interrelationship between Molecular Subtypes of Metastatic Axillary Lymph Nodes and Radiomorphological Parameters in Breast Cancer Patients who did not have Neoadjuvant Chemotherapy

Background. In breast cancer (BC), ultrasonographic examination of axillary lymph nodes is a critical prognostic factor for distant metastases and for recurrence risks. Identification of BC molecular subtype using radiomorphological features of metastatic lymph nodes would lower the volume of surgical interventions and is very important for developing protocols for chemotherapy (CTx). Purpose. To study the interrelation between ultrasound findings on axillary lymph nodes and molecular subtypes in primary breast cancer patients who did not have any neoadjuvant CTx. Material and methods. 184 women with BC, aged 24–75 (53.9 ± 0.8), who were examined and treated at the Oncology Clinic of Azerbaijan Medical University in 2021–2022 were enrolled in the study. Of these, 110 (59.8%) were primary patients who did not have any chemotherapy, whereas the other 74 (40.2%) had more than four cycles of neoadjuvant chemotherapy. Device LOGIQ C5-Premium (2012) was used to assess findings of ultrasound examination of axillary lymph nodes. Immunohistological tests of bioptat tissue were used to identify molecular subtypes of malignant tissues taken from the patients. Results. There was no statistically significant difference between the groups of patients who had neoadjuvant chemotherapy and those who did not have it in terms of hormone receptors (ER – p = 504; PR – p = 895), HER2 (p = 0.592), and breast cancer subtypes (p = 0.411). However, proliferative activity index Ki-67 (Ki-67 < 14) of the primary tumor was statistically significantly lower than threshold limits (p = 0.042) in patients who received neoadjuvant CTx than in patients who did not have it (69.1% versus 82.4%). Statistical correlation between primary tumor proliferative activity (Ki-67 ≥ 14) and HER2+ expression was noted. In TNBC subtype, oval axillary lymph nodes with irregularly thickened cortex (< 3.0 mm) were seen, while in HER2+ subtype, lymph nodes had rounded form with impaired cortical structure. Conclusion. The performed neoadjuvant chemotherapy reduces axillary lymph node metastases in breast cancer patients, particularly in those with HER2+ subtype. If hormonal receptors cannot be defined, molecular subtypes identified with axillary lymph nodes and tumor radiomorphologic features in breast cancer patients are of a large practical importance for management decision in patients with BC.