The Effect of Intratumoral Budding and Other Histological Features in Predicting Treatment Response in Breast Cancer Patients Receiving Neoadjuvant Therapy

Introduction: Neoadjuvant chemotherapy (NAC) is used with increasing frequency in breast cancers. Various clinicopathological parameters predict treatment response (TR). Tumor budding (TB), which is a prognostic parameter in many cancers, can be considered the first stage of the metastatic process. In our study, the relationship between TR and clinicopathological parameters and TB in core biopsy samples of patients before NAC was investigated. Methods: Seventy-four patients were included in our study. The association between the patients' TR and clinicopathological parameters such as estrogen (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), Ki67, molecular subtype, axilla metastasis was examined. All core biopsy specimens of the cases were evaluated, subsequently the area with the highest intratumoral budding (ITB) was determined, and finally ITB was counted in one area in a 20x objective. Cut-off was determined according to receiver operating characteristic analysis and cases were grouped as <4: low budding; >= 4: high ITB. Results: High nuclear grade, ER and PR negativity, HER2 positivity, molecular groups, and absence of angiolymphatic invasion or axillary lymph node metastasis were statistically correlated with a complete response to treatment (p<0.05). ITB was not associated with TR (p>0.05). ITB correlated significantly with ER, PR positivity and luminal group molecular subtype (p<0.05). Conclusion: ER, PR negativity, HER2 positivity, high Ki67, and high nuclear grade, invasive ductal carcinoma histological subtype were associated with complete TR, whereas ITB was not associated with TR. Further studies are required to elucidate the prognostic significance of ITB in core biopsy specimens.